#help-with-hw-design

1 messages · Page 3 of 1

heavy jasper
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And yes - I’ve had a whole board with a whack-ton of high-value tantalum caps that were all backwards due to a PnP error

vast flume
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Oh no 🤣

heavy jasper
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It was entertaining

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And a lot of work to have reworked

distant raven
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They look cool when they pop

vast flume
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Hopefully mine wont 🤣

distant raven
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A nice little plasma ball

vast flume
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In case any of you wanted some more info about my plans for this flight computer:

unknown.png
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(The renderings shown are the old version from before I switched to having usb on the board, it looks a lot more crowded now)

distant raven
knotty tiger
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nice! i like the graphic design

distant raven
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Bodge wiring mileage may vary

vast flume
distant raven
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65 parts lol

knotty tiger
distant raven
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Yeah

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Lol

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Works great 🫣

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The amazon listing said magnet wire

knotty tiger
# distant raven Yeah

heh i swear i've used that wire more often for high-density solder prototyping than for actual wire wrapping

vast flume
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How do you even go about figuring out part placement for something that crowded

knotty tiger
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run the autorouter and then yell at it a lot while undoing its mistakes?

vast flume
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🤣

distant raven
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By how close parts needs to be to the ICs lol

vast flume
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True

heavy jasper
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Stones then pebbles - big chips first, little parts around them.

vast flume
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I see

distant raven
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I do fixes placement, ICs, the passives/LEDs

vast flume
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Ah

distant raven
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Fixed placement in this case being USB, battery connector, and headers. Though I made a feather template to only have to worry about usb and battery connector

vast flume
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Actually I do have a quick question about smd leds

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I have a smd ws2812b nano on my pcb

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But I didn't realize how physically small they were until mine arrived from amazon 🤣

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How bright are these?

distant raven
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Regular SMD LEDs are usually a few hundred to maybe 1K mcd which is mini-candela

vast flume
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And approx. how many mcd would a full size ws2812b be?

distant raven
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Which depending on the viewing angle, could be 0.1 lumen to maybe 10 lumen tops

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WS2812b can get very bright. A few tens of lumens

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So probably 3-4 LEDs with the same viewing angle

vast flume
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Ah ok

distant raven
vast flume
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Oh thats not bad

distant raven
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The RGB led on my fpga board here is very bright

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That’s just green too

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This video shows the brightness of it at various stages of illumination

vast flume
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Oh so you have the same led

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Nice I think I should be good for now

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I'll prob swap it out for a full sized one in the next batch

distant raven
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This RGB LED is a very tiny 1mm x 1mm one

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It isn’t digitally controlled

vast flume
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Oh its a multicolor?

knotty tiger
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i find even the smaller NeoPixels to be painfully bright, personally

distant raven
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That RGB led sinks right to RGB pins of the FPGA

vast flume
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I see

distant raven
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24mA per channel, though it will only sink as much as the LED will draw

hushed smelt
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They’re painfully bright because there’s no diffuser.

distant raven
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These LEDs 🤓

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And very cheap

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$54 and you can get 1000 lol

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But they’re super nice

hushed smelt
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0404 is pretty small. Is that the same one Adafruit uses on feathers because even the tiny ones hurt my eyes.

distant raven
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Not it’s smaller

hushed smelt
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Good lord

distant raven
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Lol

hushed smelt
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And the pads are like right next to each other too.

knotty tiger
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like you can sneeze and lose a dozen of them across the room

distant raven
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It’s true lol

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That’s why I bought 100 of them

hushed smelt
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They couldn’t be nice and put the pads on the edges?

distant raven
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Thankfully haven’t lost one yet

hushed smelt
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Have you actually successfully flowed one yet?

distant raven
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Yeah

hushed smelt
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Geeez. Beyond my ability.

distant raven
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I also did this lol

IMG_8757.jpg
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Yay tiny soldering lol

hushed smelt
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That’s a little easier though more surface area contact.

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In a straight line and not smd.

distant raven
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Harder?

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8-uson

hushed smelt
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I haven’t tried Uson8 yet. I’m scared of killing my only Bluefruit sense.

distant raven
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Bodging is not my best skill set so the fact I succeeded surprised me

knotty tiger
hushed smelt
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Are you using a camera, microscope, or diopter?

distant raven
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I used a… magnifying lamp lol

hushed smelt
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Impressive.

distant raven
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Thanks, I’m impressed too. I did verify under my electronic microscope

knotty tiger
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right-light magnifiers are possibly underrated?

distant raven
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Mayhaps

hushed smelt
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I had a nice diopter with a huge glass lense. Base broke and threw it out when I moved. Since tried to find a replacement but everything on Amazon is garbage with a 5x plexiglass looking lens

distant raven
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Mine is like a flexible neck, light ring, and I’m guessing a plexus glass lens

hushed smelt
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Wish I’d kept it and found a way to repair the base. Didn’t realize it would be difficult finding a suitable replacement. If you have any suggestions I’m all ears.

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Adafruit doesn’t have anything like that. I did get one of the small usb magnifiers, it is awful.

distant raven
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I bought a $80 cheap electronic microscope from Amazon, protege same ones for $60 on Aliexpress

hushed smelt
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Hmm maybe I could use a high quality webcam and put a magnifying lens on it somehow.

distant raven
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Elikliv EDM9 7'' LCD Digital Microscope 1200X, 1080P Coin Microscope with 12MP Camera Sensor, Wired Remote, 10 LED Lights, Soldering Electronic Microscope for Adult, Compatible with Windows/Mac OS https://a.co/d/erJApiK

Elikliv EDM9 7'' LCD Digital Microscope 1200X, 1080P Coin Microscop...

Elikliv 7'' LCD Digital Microscope 1200X, 1080P USB Coin Microscope with 12MP Camera Sensor, Wired Remote, 10 LED Lights, PC-Microscope View for Adult Kids, Compatible with Windows/Mac OS

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This is what I got

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Works well enough

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I don’t know if I trust it enough to plug into my computer but it works for what I need it to do.

granite steppe
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Hello all, I'm trying to add Qt-Py ESP32-S2 in my hardware design.
In it's pinout section, it's mentioned how to power it from external source (mine is 5.17V power source), but I would also like to connect the USB to the QT-Py and not affect the external power source.

So adding a reverse schottky diode won't be enough, using a PMOS + schottky diode combo as power selector seems another option, but without access to direct VBUS (either as pin or as Pad on Qt-Py), how can I detect if VBUS is present?

Screenshot_2022-08-26_at_5.18.00_AM.png Screenshot_2022-08-26_at_5.12.02_AM.png
distant raven
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Vusb goes to the mosfet gate, and the mosfet sits along the 3.3V line from your external regulator

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Essentially what happens is what vusb is 0V, it turns on the mosfet. What vusb is on, it turns it off

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As long as you provide a regulated 3.3V to the 3.3V pin, it will work just the same.

granite steppe
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So bypass the onboard LDO and use one of my own?

distant raven
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Yes

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Or you can use a schoolyard diode On your external voltage input to 5V like the learn guide suggested

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I don’t really like that approach personally but it’s easy and valid

granite steppe
distant raven
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The voltages would be in parallel so it would be ~5V either way going into the ldo

granite steppe
distant raven
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Schottky diode will block any reverse voltage/current into VDD from the Qt py when it’s powered over it’s USB port

granite steppe
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At this moment it will be good enough for me.

distant raven
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Yeah, it just depends on how complex or “safe” you want to make your voltage lines. I personally opt for more complexity because sometimes it can save hassle or headache. But the easy way in this case is easily valid and likely just as good an option. Cheaper too.

granite steppe
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What are the cons of using Schottky here other than the obvious power loss?

distant raven
dry bough
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i think a mosfet ideal diode would be interesting

dry bough
supple pollen
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Power is voltage drop times current, so it's all related.

elder peak
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That's watt I'm talking about!

pale umbra
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I don't understand either what they mean by using the 5v pin as voltage input

distant raven
pale umbra
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ok 😦 I guess I'll need a diode then 😦

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wanted to use batteries to power the whole qt py and power a 5V LCD from the 5V pin 😦

onyx canopy
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Which Qt Py do you have? I have the ESP32-C3 and it has battery pads that already have the diode

pale umbra
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esp32-s2

onyx canopy
pale umbra
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I've seen this several time but I can't tell if I can do what I have in mind because I don't understand it

onyx canopy
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As far as I understand (but I’m not an expert!) you have two options. Use the battery to power both the lcd and the qt py (via the 5V pin). The diode is needed to prevent current flowing into then battery.

Use the battery pads and then connect the LCD to the 5V pin

pale umbra
#

but isn't current already flowing into the battery from itself? why is that a problem ?

onyx canopy
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As far I understand you want the current to flow from the battery to the qt py but not in the other direction, which would “charge” the battery in an unsafe way.
Again, not an expert and I might be wrong

pale umbra
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it's ok if there is 2A and -2A it will just cancel up and safely dissipate 😄

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That is what annoys me about electronics, seems like with little experience it's O(n!) sometimes where n is the number of electronic components

onyx canopy
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Something I am not sure about is with the diode it is safe to plug in the USB-C (for flashing a new version of the software) while leaving the battery plugged in

hushed blade
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You want the diode. Any amount of reverse current is bad for a battery, and even if your two power supplies are conceptually both 5V, they won't be perfectly 5V, either one could be slightly higher or lower.

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In general, there is a reason for the recommendations, and batteries are one of the few places where things can get very dangerous with low-voltage DC, you want to respect batteries

limpid nest
pale umbra
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but diodes just limit current right? they can't block it ?

limpid nest
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Reverse biased they do a pretty remarkable job at blocking it.

knotty tiger
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it depends on what you mean by "limiting current". diodes don't really limit current the way that some active current limiting circuits do (hard cutoff or foldback)

hushed blade
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I think Emporer is using current when they mean voltage in at least some cases

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there are different types of diodes, but in general diodes block any reverse voltage and let voltage through the "proper" direction (with a drop)

pale umbra
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When you just got a 15$ sensor but adafruit has something better at 1/2 of the price 😢

vast flume
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Hey guys, quick question

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I noticed that this pcb doesn't have component labels on the silkscreen

unknown.png
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Is it not required to add them?

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(Assuming it is being assembled by jlcpcb)

distant raven
unreal flax
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Board assembly is typically automated, so it goes by part-coordinate files that you submit with your board, rather than humans looking at the labels.

hushed blade
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you will eventually be annoyed with yourself if you leave them off -- you WILL eventually want to use a multimeter or rework something -- but if the aesthetics are more important than that convenience to you, go ahead

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I would probably only leave them off if the board had some sort of art on it or was really designed to be looked at. The pictured one wouldn't cross that threshold for me, but no hate to whoever made that board

supple pollen
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I used to put part designators (like R1, C1, etc.) but later found if I had room for only a designator or value, the value was more useful since I hand-assemble my boards. For debugging, I can look up the designators by position if need be. One possibility is to put the value under the part (so you can see it while you're assembling it) and the designator beside it (so you can see it when debugging).

hushed blade
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The value tends to take more room, but that's a good choice, too. >50% of the time what you want when you are looking at a board on that level is the value to assemble. The designators mostly are handy when discussing with another person, doesn't come up that much for a single developer

limpid nest
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I like designator because there isn't enough room for all the other things besides value that may be relevant

vast flume
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Thanks for the feedback

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I think I'll keep the designators on the silkscreen while in development, and remove them on any production runs I do afterwards

pale umbra
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I don't even know why adafruit and other sellers usually leave them on

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not like I'm going to replace them with 1% 5W gold premium ones as a "mod" anyway...

somber marsh
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My current project is a keyboard with some rotary encoders. I have a 10x7 button matrix wired to a feather board (RP2040). The feather has 21 accessible GPIO, I'm also using 2 for I2C and one to drive neopixels. I want to add a rotary encoder to the keyboard. Rotary encoders need two pins. Is it possible (or even a good idea) to wire and access the rotary encoder into the matrix in place of a switch? I'm using the circuitpython keypad library if that makes a difference.

distant raven
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Feather RP2040 should have a Stemma connector

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And it’s i2c so it can also use the same i2c bus you’re already using

somber marsh
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Seen those. They don't quite work where I want this rotary encoder. its in a tight space between keys. The space available between keys is a square, 19.05 mm on each side. This product is about 25mmx25mm, unfortunately. Maybe a very small IO expander would work (number of pins, I'm sure I could find some physical space for it.) It's also just (possibly) unnecessary complexity and cost. Thanks for the help!

distant raven
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Ah gotcha

vast flume
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Any tips for hot air reflow soldering a 12-VFLGA package?

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How will I know when its done & if any of the pads bridged?

distant raven
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Sometimes if there is enough space around the chip you can look under it and inspect

hushed smelt
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a proper reflow depend on heating profiles and trying to adhere to them best you can. some smd packages provide the reflow tolerances and profiles, some don't.

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most hobbyists try to get it close and cross their fingers 🤞

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even a toaster oven can be used on a professional level. adafruit literally started out making thousands of boards with a single toaster oven.

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like anything else it takes practice

vast flume
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Its also gonna be the second time I've ever reflowed something 😅

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Practiced today on a old motor driver pcb but it only had larger packages where the pins were on the outside

distant raven
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Yeah, BGA is a bit tough

vast flume
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I'm scared, this is gonna be interesting lmao 🤣

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Luckily I bought a bunch of extra components so I can mess up a bunch of times

supple pollen
vast flume
vast flume
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Says the drain to source voltage is 50v and continuous drain current is 14amp but just wanted to be sure

unreal flax
vast flume
supple pollen
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You'd need a driver board and the voltage for it. With appropriate drive voltage, that MOSFET is around 100mΩ, so would be dissipating about 2.5 watts. That would need some heatsinking.

vast flume
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Should I use a THT mosfet instead?

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Oh wait yeah couldn't I combine a THT mosfet with a transistor so the transistor can switch low-current 12v and be controlled by my microcontrollers 3.3v, and then in turn switch the mosfet?

supple pollen
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Yes, you can build a transistor based gate driver circuit. THT is often easier to heatsink, but it is possible to headsink SMT with sufficiently large copper area and plenty of via stitching.

supple pollen
vast flume
supple pollen
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Usually it will have more resistance and need higher gate drive to work than a lower voltage MOSFET.

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More resistance = more loss = more heat to dissipate

vast flume
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Higher gate drive as in it would drive more current?

supple pollen
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No, it may require both higher gate voltage to turn on fully, and have more gate capacitance to charge/discharge

vast flume
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The one I sent says the drive voltage is 10v

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But yeah at the same time I calculated 70w of power dissipation...

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Wait no my math was completely wrong

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It should actually be 1.9w

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Would this one work better if I controlled it with a transistor?

inland jungle
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You can use an optocoupler with a transistor output to drive a mosfet

vast flume
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The Rds_on at 3.3v is only ~0.025ohm; so at a 5amp load that would only be 0.625w of power dissipated. Am I reading this correctly 😅

unreal flax
#

You previously were considering an N-channel FET, and this is a P-channel one, so if you're switching 12V, that could be a problem with a logic-level input.

supple pollen
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The specs you quote sound good but I'm on my phone and can't double check the listing

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Oh, yeah, you'd still need a level shifter for a P-channel unit but there should be comparable or better N-channel units available since it's easier to build high performance N-channel FETs

vast flume
#

This one looks like a N channel mosfet with comparable specs

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rds_on of 0.024 at 3.3v

hushed blade
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mosfets that are driven by 3.3V are annoyingly hard to find, unfortunately.

void sentinel
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I am wondering who to use for pcb fabrication?

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That link is not very informative. Should I delete and repost here?

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The only design checks that I approved are dimension errors on the usb micro I used from the Adafruit's M0 proto board.

supple pollen
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There are lots of choices for PCB fab

void sentinel
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That is why I am asking. Have you ever made one? who did you use? what have you heard? what am I doing wrong? lol

tough matrix
#

how many boards do you need? how quickly do you need it?

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for small boards or when speed is crucial, Oshpark is a great choice

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for anything else, I normally use jlcpcb

tough matrix
#

As for board review, can you post PDFs rather than screenshots? it would be easier to read.
Two first questions:

  • did you run DRC?
  • how will you program the SAMD21? usually it is done using an SWD programmer, but then you need to provide a header (or test points) on the board for connecting it
vast flume
#

Is this the correct configuration for a pulldown resistor on an output pin?

granite steppe
vast flume
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@granite steppe D6 is going to the gate of a mosfet ic. Does that change anything?

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I read about sometimes wanting to use a "soft" pulldown on gpio outputs, but couldn't find any values for what that could be

knotty tiger
granite steppe
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A P-channel or N-channel Mos? Is the gate connected to anything else? What's the Vgs of the MOSFET? What's the resistor used for, gate discharge?

knotty tiger
#

hm, yeah for n-channel, i think driving the gate actively low for turn-off might be preferred, if the GPIO can sink enough current?

granite steppe
woven bluff
#

is there a LCD that can be mount directly on top of Feather doubler or tripler ?

knotty tiger
woven bluff
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doesn't matter

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from the size of Feather doubler or tripler , it cannot be alphanumeric

knotty tiger
#

can you elaborate by what you mean by "mount directly on top of a Feather double" etc?

woven bluff
#

aligned screw holes

knotty tiger
#

so a standard Feather/wing form factor?

woven bluff
#

more like twice the Feather form factor

knotty tiger
woven bluff
#

single Feather is too small, there's 128x64 OLED and ESP32-TFT

knotty tiger
#

yeah most of the larger FeatherWing displays don't seem specifically designed to plug into a doubler/tripler

vast flume
vast flume
granite steppe
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Go for the 10kΩ then.

vast flume
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Awesome, sounds good

supple pollen
hidden marsh
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If i power the digispark attiny85 with 3,5 - 4v at VIN can the voltage regulator handle that?
The datasheet of the regulator says 5-35v bit datasheets for the digispark say something about 7-35v.

Can undervolting that regulator kill the attiny or other chips connected to the 5v rail?

knotty tiger
#

undervolting can result in unstable behavior, if the clock speed is faster than specified for that supply voltage. on occasion, it can result in permanent damage of devices that contain boost regulators, due to overcurrent conditions from trying to boost from too low an input voltage

rustic fulcrum
#

I want to monitor the voltage output from some batteries with a QT Py. Am I correct in saying that I can just have the +/- from the battery go to two of the same value resistors, that'll halve the voltage, and as long as the resulting voltage is below 3.3V, I can then connect the output to an analog input pin and read it to monitor the battery voltage? Is this (utterly terrible) circuit diagram basically correct? Would A1 be getting 2.25V and be able to read that easily in code?

Artboard.png
unreal flax
rustic fulcrum
# unreal flax Yep, that's all correct, although you'll want to think about the value of the re...

Ah great, I wasn't sure about whether this somehow changed ground and I wouldn't just get one output pin or not. The resistor value thing and current used is indeed a big thing for me as I'm targeting below 100uA for this circuit (during deep sleep), so are there some absurdly tiny resistor values I can use that'll use almost zero current? I just picked 100 as a random value to make the diagram.

unreal flax
rustic fulcrum
unreal flax
rustic fulcrum
#

the electrons.. they do things

knotty tiger
#

sometimes small-valued resistors are the physically largest (because they have to dissipate more power)

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(somewhere, as part of the power system of Boston's MBTA, is a 1-Ohm resistor the size of a small house)

rustic fulcrum
knotty tiger
rustic fulcrum
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And yeah.. this is definitely a case of me having a very bad basic understanding of how something in electronics works. I thought resistors inhibited current and dissipated it as heat, but at the same time, I thought that current was only pulled by other things, or ohh, resistors pull current all on their own?

knotty tiger
#

it depends on what else is in the circuit

rustic fulcrum
#

..getting tempted to just order the fuel gauge breakout just so I can just do voltage reading over I2C 😉

knotty tiger
#

i think even some Feather boards have a simple resistor divider to let the MCU read out battery voltage

rustic fulcrum
#

Most Feathers have a fuel gauge chip built-in, the problem is that for a couple of projects I'm doing I really need/want an external antenna, and there's no ESP32-S2 Feather board that has that, have to get a QT Py for it

rustic fulcrum
knotty tiger
rustic fulcrum
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So the dissipation is only about current that can actively get through it, and resistors don't take current and dissipate it as heat themselves?

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I think my knowledge that resistive heating is a thing is probably confusing me here a bit

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Plus that I assumed an analogue input pin wouldn't really take almost any current

knotty tiger
knotty tiger
rustic fulcrum
knotty tiger
rustic fulcrum
knotty tiger
pale umbra
rustic fulcrum
pale umbra
#

sure it does

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never seen condensation on pipes ?

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I had a cat who drank that way no matter how much I put near its food

rustic fulcrum
rustic fulcrum
pale umbra
knotty tiger
# rustic fulcrum Is this it? The 50nA numbers?

maybe? I_IH and I_IL are probably for digital inputs, but typically they're leakage currents that might also be included in the analog input leakage. see if there's a section for ADC characteristics

rustic fulcrum
knotty tiger
# rustic fulcrum

hm, i would expect more details than that. is there a different section about using the ADC?

rustic fulcrum
knotty tiger
#

(e.g., the ATmega32U4 datasheet has an equivalent analog input circuit shown in the ADC usage section)

knotty tiger
rustic fulcrum
#

So the amount of current that a voltage divider will use is dependent on the amount that the analog input pin will pull

knotty tiger
#

it might be that Espressif has a separate document for a ADC peripheral module that might be shared across MCUs

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i would go with assuming the 50nA digital input current as a starting point. as long as your resistor divider draws 10-1000 times that much current, the errors shouldn't be too large (especially if you follow the other advice from EdKeyes to put a capacitor there)

rustic fulcrum
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But I want it to draw as little as possible is the thing

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If it helps, I have a ESP32-S2 TFT Feather, a Nordic PPK2, and a SparkFun book of resistors here

knotty tiger
#

i guess you could have an op-amp buffer that you only power on while sampling the voltage, but that's more complexity, and you'd have to make sure it can handle the inputs when unpowered, and that the op amp input leakage is lower than your resistor divider

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i would suggest first getting your power usage as low as you can without the voltage measurement, so you know how low you might need to go with battery voltage sampling current

rustic fulcrum
#

Unless you just mean as to whether it essentially matters compared to the overall current used

rustic fulcrum
knotty tiger
rustic fulcrum
knotty tiger
#

@rustic fulcrum you said you're targeting 100uA in deep sleep? how much current consumed by the voltage divider can you tolerate?

rustic fulcrum
knotty tiger
rustic fulcrum
#

I've got a kit with 0Ω, 1.5Ω, 4.7Ω, 10Ω, 47Ω, 100Ω, 220Ω, 330Ω, 470Ω, 680Ω, 1kΩ, 2.2kΩ, 3.3kΩ, 4.7kΩ, 10kΩ, 22kΩ, 47kΩ, 100kΩ, 330kΩ, and 1MΩ resistors, already

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Am I right to assume that I shouldn't be able to break anything if I take the 3V3 pin and wire it to an analog input without any resistors, and that the resistor values also can't break anything?

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Just wondering about testing this with the PPK2 but obviously want to limit any magic smoke potential.

knotty tiger
knotty tiger
rustic fulcrum
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I'd be testing it with an M4 then a ESP32S2 TFT Feather initially (partly as I have headers on the M4 and partly because I'm happier to accidentally fry it rather than the TFT)

arduino_compatibles_Feather_M4_Page.png adafruit_products_Adafruit_ESP32-S2_TFT_Feather_Pinout.png
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Can you tell I magic smoked a Particle Photon years ago and it stuck with me? 😉

knotty tiger
rustic fulcrum
#

Though this is also relevant because one of the projects is a mailbox notifier and the plan has been to have it work by having the flap opening break a circuit (copper tape etc.) and wake it from deep sleep to send a message, and I was figuring I'd use the 3V3 output for that too

void sentinel
#

Adafruit does what you are talking about in their M0 basic rev c with 100k resistors to pin 9...

Screenshot_2022-08-29_191220.png
void sentinel
# tough matrix As for board review, can you post PDFs rather than screenshots? it would be easi...

I can post any way that helps you help me... 😉

I copied the adafruit M0 proto and mcp9600 break out and added a max485 chip with it's pull ups and caps. So I have the swclk and swdio broke out. I have never programmed them, but did see that Adafruit had a tutorial and skimmed through it as I do. I could post brd or sch files or whatever. I did the ferric chloride thing 30 years ago in high school. I have had a spare toaster oven for years now, but haven't got around to converting it. I do not have much smd experience that I cant do with a fine tip soldering iron. No hot air yet... So I want to eventually do stuff with stencils and reflow my own, but it is hard for me to stay focused long enough to finish things without proper motivation. I am easily distracted... So I feel the need to compare. I want only a test sample but I want potential for assembly to compare cost. I am not really in a hurry, but would rather not wait more than a couple weeks. different people want different files. or formats. most are the same but there are differences. Also I am not comfortable editing individual layers or knowing which is which. Other than an obvious name. like is the silk_top the silkscreen or silktop or both and why is there 2 and I need a glossary lesson. place, names, values, stop, cream, finish, glue etc. they glue things now? I am a fast learner. So today will be Eagle binge day I guess.

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wow sorry so long

pale umbra
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can't help with the smd / pcb because that is above my level but seems like a nice project

void sentinel
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Do all these different assembly companies just happen to have the parts you want to use? Assembly prices are all over the place. digikey has a pcbuilder thing and there are prices from like 9 to 50 per part. wow. it's a robot. how can there be such a spread? No one says would you rather pay 177 for this or 1081? You know, because you can?

unreal flax
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(There's a setup overhead for loading the robot with each type of part, that is, which can be a big deal or not, depending.)

void sentinel
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that is what I had assumed. There are so many out there and if this community already has ones they use (and importantly: don't use) there are obvious reasons and I am not trying to reinvent anything. I wish I wasn't making such a big deal about it

pale umbra
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you may have to provide the parts

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personally I would prefer one with an online quote system and different options so I can decide what I want to compromise on or not and the consequences

void sentinel
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As far as pdf. what do you want in it? Am I exporting something from Eagle to the pdf and anything in particular that is preferred or just pasting the images into it? and if the latter, how is that different? Also I have a lot of dimension errors but they are all from the same part. The micro usb jack from the M0 basic. I approved them. lol. And stubs keep showing up like the file readjusts and just adds these bits. If deleted there is an airwire. sometimes I change the path to see if it helps sometimes it's the same. Sometimes the same ones reappear and sometimes...

pale umbra
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also personally i would check https://www.reddit.com/r/AskElectronics/wiki/buying/pcb/ for recommendations, because recommendations from here are going to be personal preferences as there is no one that generally speak for adafruit here or for the community

reddit
buying/pcb - AskElectronics

r/AskElectronics: This is a technical ELECTRONIC ENGINEERING subreddit, covering practical, component-level circuit design and repair, electronic …

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whereas reddit electronics strenght that they have recommendations from answering questions over the years

void sentinel
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I feel that I can reflow these. To me they dont have the pins in the middle and have less of a chance of shorting. bga/qfp or whatever

pale umbra
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the ones who are going to print your pcb will usually tell the specs and how they want the export

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my local one has a 20 pages document on correctly setting up fusion 360 export for their machines

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them rejecting a pcb design is free afaik 😄

void sentinel
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I am here for the very knowledgeable and experienced community and do not expect anyone from Adafruit to help me unless they wanted to lol. I mean I am not against it.

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I have never used paste. It has always looked so wonderful to me. I have always been a 60/40 .032 kind of solderer.

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is there a certain size range that is going to cost the same? as in 4 different 2in boards or 1 4in board that is really just the same board copy pastaed? I am guessing those are what they mean by panel?

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I uploaded just my .brd file to oshpark and they showed an image of it on their purple board and said 3 would cost me $21.70.

pale umbra
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this discussion make me realize that I should move to the US or shenzen 😦

void sentinel
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Is it really that easy? other sites are all with the gerber and whatnot

pale umbra
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did you leave an email ?

void sentinel
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I am about to I think lol I don't even see a need to look further.

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Oh except I am not satisfied with my silkscreen.

pale umbra
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you do know that it doesn't usually include pcb assembly right ?

void sentinel
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I think I am just going to do that part myself. Why not?

distant raven
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It’s great experience

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I do it a lot

void sentinel
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there are not a lot of parts and I really only need 2 or three to demo

pale umbra
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because of where I am geographically personally Id probably go with jlpcb or another asian pcb maker 😦

distant raven
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OshPark after dark PCB hand assembled

723F6691-02CA-4776-B423-B9E08DE0CABA.jpg
void sentinel
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I am not picky. you were the one with the watch weren't you @distant raven

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that is so crazy

distant raven
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Yeah, I’m making the watch

void sentinel
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is that just moded?

pale umbra
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the problem in Canada is that there is probably such service

distant raven
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Well, watches

pale umbra
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But they talk about their service like the minimum is 1 million PCB

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so I'm never sure about electronics services in Canada

void sentinel
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what is the zz component? antenae?

distant raven
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Close up of the watch

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Hand assembled as well lol

void sentinel
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I saw you post that pick a few weeks ago. It is gorgeous! That color is neat too.

pale umbra
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should have been a white pcb imho and actual feathers (not the electronic feathers) 😄

distant raven
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I’ve also hand assembled panels like this lol

3329DE45-C9FB-4C7A-AA22-8BFACFB73B35.jpg
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So anything is possible

pale umbra
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if you are starting from zero though aren't you going to spend a lot to get the hardware to do pcb assembly ?

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like the smd gear, 300$ hot gun, 2000$ hot plate, the 50$ per stencils etc ?

distant raven
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Tweezers, a $80 hot plate, $100 reflow gun, $7 for a JLCPCB stencil

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If you’re feeling spicy you can buy an $80 tshirt silk screen jig to have a more sturdy pasting station

void sentinel
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I got your piwatch right here

PXL_20220830_003701735.jpg
distant raven
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Maybe like $400-$500 that will carry you through hundreds of projects

pale umbra
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ok the chaper hot plate on amazon from a decent brand seemed to be like 1000$ 😦

distant raven
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After that, your recurring expenses are additional components that you don’t already have, solder paste, etc..

void sentinel
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looks like a qtpi

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stencils are that cheap? wow that's great

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what is the temp of hot plate normally?

pale umbra
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jcl are kinda agressive with their pricing, I trust them as "good/cheap" option just like elegoo

distant raven
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This was $85 when i bought it

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Weird name but it works pretty well

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YIHUA 862BD+ SMD ESD Safe 2 in 1 Soldering Iron Hot Air Rework Station °F /°C with Multiple Functions https://a.co/d/7su1kiK

YIHUA 862BD+ SMD ESD Safe 2 in 1 Soldering Iron Hot Air Rework Stat...

A 75 watt output soldering iron with temp range of 200°C - 480°C / 392°F - 896°F with Silicone cord that are extremely pliable and virtually. Suitable for SOIC, CHIP, QFP, PLCC, BGA and temperature-sensitive components. Fits for heating shrink, drying, lacquer removal, viscidity removal, ice-out,...

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I use this solder station

void sentinel
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is the same one...

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it's amazon

distant raven
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Pretty much the same one. Slight difference on the temp display but functionally the same

void sentinel
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ah hot air

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that is one of my next investments. ok plate vs oven?

distant raven
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Plate works good enough to get started

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If you’re doing a lot and want something slightly more hands off, try modding a toaster oven with the Reflow Master Pro from UnexpectedMaker

pale umbra
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I guess I'll make my own hot plate eventually

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these don't feel safe at all and no brand stuff (probably because they dont want to be found)

void sentinel
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I have a heat gun. I know it would be awkward, but could I do aluminum foil nozzle action on that?

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it is as safe as you make it hehe. I am down for making my own plate too. You can buy a regular cooking hot plate probably. What is the operating temp? 300ish?

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less than 50

pale umbra
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it doesn't have any electrical cert that is what I mean that CE is as meaningful as if I wrote it with a pen and it's a very common design that was probably assembled on someone street food cart.. and I said "decent brand" above but anyway...

void sentinel
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Ok I am off to watch silkscreen how tos. What is the difference between the layers silk_top or silktop

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I dont agree with ce and ul meaning very much. there is a lot of junk out there.

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expensive things that fail in certain ways repeatedly that were engineered to be that way even...

pale umbra
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I don't mean failure I mean basic human safety because I don't like living in fires or touching a conductive thing which is the basic thing that UL/CE test

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but maybe I'm missing something and everyone here put asbestos suits when they do heat stuff, have ceiling gas fire extinguishing systems, electrical gloves etc...

rustic fulcrum
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If you only need a teeny hotplate, the Miniware USB C one looks great and I think ladyada uses it

pale umbra
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honestly using a pan and a stove feel safer than the above...

rustic fulcrum
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Also if you're doing anything battery/low power @void sentinel , the Nordic PPK2 is excellent

pale umbra
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what tell me that whoever made that blue device even know anything about electronics and they didn't even do basic safety measures ? their "word" ?

rustic fulcrum
pale umbra
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most fires nowadays in my area is from uncertified cell-phone chargers shaped object

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yeah I'm trying to figure out whenever I ask for recommendation from a decent brand here I'm told about things that don't even have basic safety...

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since we had a sears and zellers close a few years ago I guess getting a big used toaster could do the job too

void sentinel
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I already solder. i just haven't used hot air yet.

pale umbra
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I might get it because I cant stand that sticky flux anymore .... 😄

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do you even need a soldering specific hot plate or that's just to avoid ever forgotten and putting foods on it ?

rustic fulcrum
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I'd assume yes, in part because you want to have temperature control that's precise

pale umbra
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induction cooktops seems to have good temperature control

void sentinel
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I have an induction frying pan 😉 they are neat. I have a copper one

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"copper"

rustic fulcrum
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It's just so cute:

4948-09.jpg
void sentinel
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That is awesome. I never noticed it b4

pale umbra
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getting r/c stuff is my next purchase, but better soldering stuff would be the 3rd after that...

rustic fulcrum
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Yeah, I've seen ladyada use it on streams a few times.

pale umbra
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I've seen the blue plate above used on documentary in africa from ARTE but my issue is the randomly-named brands that seem to make it over and over

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I know they work, just like those tiger generators, but I'd trust original ones more than the randomly-named brands ones

rustic fulcrum
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I do need a new soldering iron hmm

void sentinel
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thats how manufacturing works. one company makes it, then the other companies pay to have their stickers put on...

pale umbra
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yeah we don't know if the made it like the original or ruined it in their clone too

void sentinel
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as long as you know the base package, you are fine

pale umbra
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@rustic fulcrum I don't recommend the hk888d it works a little too well does 0 to 750oF in less than a minute you have to be agood a t soldering and it's obviously meant for pro/industrial use and doesnt allow for mistakes much

rustic fulcrum
pale umbra
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not everything is meant for hobby use allowing mistakes etc

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is what I mean

rustic fulcrum
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yeah, but I don't get how that's the case here

knotty tiger
pale umbra
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temp at which my lead starts to melt (700oF), I lower it when it's on my pico as the pad/tip heat better

knotty tiger
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hm, should melt well before there, for 60-40

pale umbra
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not sure the display represent the actual temperature but cant calibrate it

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so I just wait for it to get to 650 and since it heat really fast start to aim my solder and start my work at 700

rustic fulcrum
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Yeah, 700F is more for lead free solder

pale umbra
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military-grade soldering 😄

knotty tiger
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calibration for a brand-new iron shouldn't be that far off

rustic fulcrum
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Wait, is the Hakko 888 what you were referring to as a "military" soldering iron? It's a really good one.

pale umbra
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yeah the D one though, people prefered the A one (analog)

rustic fulcrum
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Hey I mean I'll take a Hakko 888 off your hands if you don't want it 😉

knotty tiger
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if your 60-40 solder isn't melting until 700F and you're also having trouble with flux burning off and desoldering nearby components, it sounds like your heat transfer needs improvement (better iron tip tinning, more flux, etc)

pale umbra
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it didn't desolder anything the first shifter had an issue

knotty tiger
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i prefer irons with digital readouts so i can see in real time how quickly it's losing heat to a given soldering configuration

rustic fulcrum
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Yeah, I mean I assume my soldering experiences are bad because I'm using a 25W Antex iron with no heat adjustability and SAC305, but a Hakko plus leaded solder should be easy

pale umbra
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the 2nd and 3rd one went perfectly

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2nd and 3rd shifter

IMG_20220828_183351.jpg
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so I guess the 1st one just had a defect and it probably got washed off by a flux wave or something...

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I'm almost in 😻 with some of the solders at the top, wish it always turned up like that

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pico went really went of course because the pads are copper and much bigger, it's just these tiny ones that are very hard to do...

knotty tiger
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yeah sometimes with cheaper SMD boards, the reflow profile isn't dialed in quite right and there are some marginal joints that can be easily broken

pale umbra
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differences between ease of soldering pico vs those level shifters...

IMG_20220828_183332.jpg
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the pico will allow for for mistakes/bigger margin than these shifters...

knotty tiger
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they both look like 100mil centered pin headers; i guess the pads are a bit wider on the Pico?

pale umbra
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yeah, at least 5-6x and the pins go higher

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and the pads/pins seems to conduct heat better

void sentinel
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careful with too much solder

pale umbra
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only problem I had on the pico is 2 solder bridges so I can just lift it up by touching the sticky flux now and raising my finger 😦

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tried to clean it with alcohol but wipes dont seem to work well

knotty tiger
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anyway if anyone's interested in a less expensive but still decent soldering station alternative to the Hakko 888D, i happen to like the WESD51 (only 50W vs the Hakko's 65W, but works well enough for many purposes)

pale umbra
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here it was more expensive than the 888D

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so I got some tips for the price difference, the 888D was 101$ at pishop

knotty tiger
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interesting, it seems the WESD51 has been discontinued? i wonder for how long

rustic fulcrum
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Was just looking at the ATTEN ST-60/ATTEN ST-80

pale umbra
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I accidently soldered my finger also the other day so I can now power myself with a battery instead of food since I now have a 5V pin

void sentinel
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I guess I do have the tool. I have used it to shape plastic, but I think it would work. This is my favorite, or was. It is old and doesn't get as hot as it used to.

PXL_20220830_021551984.jpg
rustic fulcrum
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Adafruit sell the ST-2090D and so I'm assuming that the fancier ST60/80 are good too. Wondering if there's much point/advantage in getting the 80W version instead of the 60W?

pale umbra
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I'll receive my chemtronics wick this week as well

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80-5-5 whatever that mean

knotty tiger
pale umbra
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shame that my iron isn't hot enough to solder aluminum though 😦

rustic fulcrum
pale umbra
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I was unable to reuse rca connectors because of that limitation

tough matrix
# void sentinel I can post any way that helps you help me... 😉 I copied the adafruit M0 proto ...

sorry, I was slow to respond and there has been a lot written here in between.
I do not have Eagle anymore - switched to KiCad - but if you post here pdf of your schematics and board files, people can better see and comment.
And I'd say that if you have never done smd soldering, starting with SAMD21 chip in QFN48 package will be quite challenging. But @distant raven can tell you more than me on this subject

distant raven
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A good stencil is crucial for getting a good solder finish the first time

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I’ve also found that if you don’t have a stencil, lay a bead of paste from a syringe of paste, reflow it and then use a chisel tip on an iron with some flux and place and drag out from the pads on the broad edge

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I usually don’t buy stencils for prototypes because I’m cheap but also know what works and doesn’t

rustic fulcrum
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ponders just giving in and spending all the money on a Hakko FX888D

woven bluff
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at home I use one of those Chinese made iron with all control circuit integrated in the handle

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temperature adjustable with a thumb wheel pot

hushed smelt
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@rustic fulcrum I didn't even know Adafruit had something like that. That one is really nice. The Weller I have looks similar but it's 48W. The higher wattage allows the iron to heat up faster and maintains heat easier. Honestly if I knew that one existed I probably would have gone for it instead of the Hakko 888D. The Hakko is overly complicated for no reason. It's got 2 digital buttons for navigating and setting the UI... imagine if your microwave oven had 2 buttons... that's what it feels like, it's stupid and overly complicates what should be a simple process if there were 4 buttons and a keypad. The ST-2090D keeps it simple, powerful, and can use hakko tips. Looks like a winner to me.

void sentinel
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Grrrr no it doesn't

Screenshot_2022-08-30_034412.png
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Does it search the bitmap for certain colors? I expected it to only want 2 colors. That's what I did. I wasn't sure if it should be black on white or the inverse.

rustic fulcrum
void sentinel
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i forced monocolor and it worked, however with no config change, the scale was wrong.

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Oh my. That wasn't bad

v2.0.png
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Ok now I used those stupid default vias, but I really wanted the narrow tented ones.

void sentinel
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my via can only go to a certain minimum in my diameter options and drill options. These via from the pink 2040 are tiny. How can my via be tiny via?

2040pinkvia.png myvia.png
void sentinel
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Ok now I wait. This was so much fun. Thanks everyone so far. I will be back when I need help with the bootloader lol.

oshparkhistory.png
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Oh yeah, now to Digikey...

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do they happen to have a bom search thingy? that would be convenient.

distant raven
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@void sentinel you can edit the Design Rules to get smaller via size and change the mask setting to tent via.

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I would have also put a ground pour on top and bottom give that massive D-PAK part

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Then put via in the thermal/ground pad for that d-pak to better sink heat.

void sentinel
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I wanted to do that, but this is just a test

inland jungle
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what's the best way to wire up 25 microswitches so that you can detect the state of each one, with any number of them being true or false at any given time? Some sort of parallel to serial encoder?

hushed blade
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if you're gonna use a microcontroller, look at how keyboards are wired up. the good ones have something called NKRO or N Key Roll Over, which means you can press any number of the keys without issue

inland jungle
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yeah, reading about it now, thanks

unique patio
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@rustic fulcrum The Hakko 888D is a good unit, but it has a terrible user interface. It's easy to mess up the calibration when you meant to change the temperature. So if you get one, read the directions carefully. ... I bought a used 888 analog unit partly to avoid this problem.

pale umbra
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I thought so too but the video is very clear on how to use the UI so I disagree

inland jungle
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I think I ran into that issue once or twice

pale umbra
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There are videos and the manual https://www.youtube.com/watch?v=r1pl61mbhOo but it feels like programming the apollo 11 lander sometimes (function is just a number, etc)

YouTube
HakkoUSA
Hakko FX-888D Soldering Station by American Hakko — How To Change t...

This is the official video from American Hakko — Learn HOW TO "change the preset temperatures" that are used in the preset mode of the Hakko FX-888D soldering station.

The Hakko FX-888D is an updated digital version of the popular FX-888 and includes several new features, including preset temperatures, digital calibration, password protection, ...

▶ Play video
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I guess it's harder for younger peoples because they didn't have to change the clock on their vcr/dvd player attached to the tv before

distant raven
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Feels slightly disingenuous

knotty tiger
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i think that style of minimal interface is very error-prone whether or not the user has prior experience with UIs such as VCR clocks

distant raven
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Being young != technically naïve to older technology. There are plenty of older people who likely would struggle operating it as well. So let’s not cast nets and generalize.

pale umbra
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yeah I think so too, just saying it's not completely impossible and you just have to go throught it once until the manual explained tip maintenance

knotty tiger
distant raven
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My Yihua solder station(or as I call it my rodeo solder station) has a pretty simple but useful interface

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Pay no attention to the highly flammable 99.99% IPA on top or the charging cable running over the top lol

pale umbra
distant raven
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Hold a button until it flashes and the press it until you reach a number, wait a few seconds for it to switch to the next hours/minutes, press it a bunch again and then bam, it’s set lol..

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My Hamilton Beach coffee maker is like this for programming the time and auto start

pale umbra
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yeah that's even worse than the hakko 😦

distant raven
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Luckily there is also pre coffee brain mode where you just hit start

pale umbra
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I wish they made replacement card for the UI and face and allowed one to change them

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for me personally it's the using numbers instead of names like the apollo 11 lander that bother me

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having an up button wouldn't solve it, can't understand why they didn't just slap in a cheapest of the 5$ cheap 1602 LCD...

unique patio
pale umbra
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yeah that's how time was entered back then on a vcr after every power shutdown

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if you wanted to set 12:00 you had to press once for the 1, twice for the 2, then hit menu or do the whole thing until the 0 to set it

unique patio
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So for temp adjustment you use the ENTER button; for calibration adjustment you use the UP button

pale umbra
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all of this while the iron is searing hot 😦

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because of course you have to power the iron to set this 😦

unique patio
#

The addition of a single extra button would have helped enormously

pale umbra
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or a small keypad...

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with numbers

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they are 3$

unique patio
#

another example of silly design:

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My Breviile toaster oven

IMG_2504.jpg
pale umbra
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or mustard bottles without a squeezing action/dispenser...

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because using a spoon is so accurate....

unique patio
#

four buttons, but you need to press the TEMP button and then use the arrow keys to change the temp, and press the TIME button adn then the arrow keys to change the time. But there are four buttons. There could be up/down arrows for TEMP, and up/down arrows for TIME, eliminating the modal nature of the interface.

pale umbra
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BUT the one I dislike the most, virtual keyboard on cellphone...

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I never found the secret...

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I don't know what model of humans is supposed to have small enough finger to use them, same with the tiny buttons adafruit & co put on board and I'm scared of shorting the board when I have to press one...

hushed blade
#

my oven is the same interface, still. so are some (this is slowly vanishing) clocks in cars. really, the vcr was nowhere near the only place this style interface is/was used.

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and yes, it's a bad interface in all of these cases.

pale umbra
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same for my stove 😄

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despite all the space

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but at least my stove has a chip to keep time

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I like how you don't even have to set a password to keep your hakko 888d secure, the difficult UI does it already 😄

knotty tiger
# unique patio

wow that's even worse than i thought! almost as bad as some Airbus(?) avionics distinguishing safety-critical mode information by the status of a decimal point in a 7-segment display that led to a crash a while ago

pale umbra
#

so err, polyester capacitors are legal ?

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doesn't seem like a good idea to me to put acid in textile to make capacitors ?

inland jungle
pale umbra
inland jungle
#

I pushed the wrong button when setting a temperature, so ended up setting the calibration temperature to a wrong value, just checked with a thermocouple and I was waaaaay off

pale umbra
#

which thermocouple ?

inland jungle
#

I'll double check by testing the melting temp of SAC305

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I used a type K thermocouple

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and a handheld meter

pale umbra
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handheld meter didn't work for me because the tip is too small

pale umbra
void sentinel
#

Sometimes the complications are to verify to ensure change is not accidental

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The are you sure pop up vs: sudo rm -r *

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No redo undo ctrl z etc

inland jungle
void sentinel
#

I imported a bitmap into the layer 21 and it wasn't right. I couldn't unrun the script. It was too late. So I closed without saving and imported it into a different layer, then when it was good, I changed it's layer to 21...

pale umbra
void sentinel
#

That doesn't happen programming a vcr.
I deal with temp controllers and other things that have much more complicated configs.
Look how complicated a Eurotherm Nanodac can be.
Compare that to a Honeywell 2000 for example...
Oh wait. I was talking about setting vcrs.
What is my context?

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It doesn't matter the context. You are talking about menus

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That is the subject. Navigating menus

pale umbra
#

sudo -rm -r * and bitmap/layer 21 is related to vcr ?

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I'm confused now

void sentinel
#

Sometimes you have short presses and long presses to do different things with only one button.
I was annoyed when they changed 2 knob radios to button volumes because you couldn't turn it down as fast. Then I redesigned it so everything had it's own button and it was too noisy. Too many buttons.
I/O is a compromise on functionality vs user experience.

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The idea of confirming your choice was the reference to that

pale umbra
#

a knob would have been better but even then I remember having to be really careful to be precise because the knob would jump by 10 to "help me" but I wanted 2 or 7

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and it was almost impossible to get 2 or 7 because even by turning it really slowly it would jump between singular values

void sentinel
#

One metaphor goes like this:
6 of these
Or
half a dozen of these
Which one do you want?

#

Sometimes you scroll your mouse wheel and it moves 1 sometimes it moves 10.
We want it to move 5 though.
The magic is in the software somewhere...
Why can we access every single little config?
Hardware hacking. You control firmware, you "control" the device.

#

Too many choices. The programmer does it for you. You do it their way. Or you hack the device. Or you buy something else. Or make it yourself.

#

I mean, i am the king of off topic or tangenting or adhd or whatever. You say the topic was vcr. I say the topic was settings on a solder station. I thought all the other was just banter...

#

10 degrees is a bit

#

If you care about accuracy

rustic fulcrum
void sentinel
#

Sometimes the operator doesn't calibrate and they just offset the setpoint...

pale umbra
#

Personally I just live with the factory default 😦

#

Also I like black PCBs so it's okay

void sentinel
#

That's always good

#

I have a Beagle Bone Black. They are sweet.
These days there are a lot to choose from.

#

Colors...

pale umbra
#

Wish you could choose the color of the PCB when ordering even if I know that's almost impossible

#

would be handy to color-code things at first glance (like yellow for 3.3V, blue for 5V, red for breakouts etc)

void sentinel
#

All the places I looked at, I could choose. I like the looks of the purple. Actually I like all the colors except boring glossy green because it was the only color... I have even recently seen matte green. It is cool.

#

Oshpark does purple by default and I didn't even check, because I was good with it. Pink and light blue and all the colors are sweet cuz they're different.

hushed blade
#

oshpark is purple by default and they also offer black. They don't have a huge set of options.

#

The black looks pretty sweet in photos, I haven't ordered one yet

pale umbra
#

the pcbs should be clear and they run a coin battery led under it 😦

void sentinel
#

Pcbway

Screenshot_20220830-150517.png
hushed blade
#

your gerbers can control where copper and soldermask is (soldermask is what has the actual color). in theory you should be able to get something quasi-clear by removing both of those

void sentinel
#

Jlcpcb

Screenshot_20220830-150631.png
hushed blade
#

IIRC, in afterdark the pcb material itself might be black and the soldermask is clear? but with the purple one it should work

void sentinel
#

Pcbs are made of fiberglass fiberglass isn't clear

hushed blade
#

yeah, the big chinese manufacturers have much wider color options. for my specific use cases they don't wind up cheaper (once I add shipping) and they take way longer to arrive. But your case may be different.

void sentinel
#

I could imagine a copper foil on acrylic. That would be awesome

hushed blade
#

pcbs are made of fr4, which is similar to fiberglass, also fiberglass can be clear -- boatmakers often put a layer of epoxy fiberglass on the outside for strength and it winds up being clear in that application

void sentinel
#

The epoxy is the clear part

hushed blade
#

plain fr4 can often be "quasi-clear", meaning somewhat translucent. but I've never seen one like glass clear, in case that isn't clear

void sentinel
#

Yeah like opaque...

hushed blade
#

if the index of refraction matches, epoxy + fiberglass winds up clear. it's not that fiberglass isn't clear, it's that the edges of the strands refract the light

void sentinel
#

That raw brownish

knotty tiger
#

glass fibers in FR-4 are small enough to scatter plenty of light, preventing it from being actually transparent (yeah i guess if it's index-matched it could become transparent, but i've never seen that accomplished)

hushed blade
#

look at boat makers, they put sheets of fiberglass on the outside of a wood boat, use totalboat epoxy which is purposefully IR matched and you cannot see the fiberglass at all

void sentinel
#

The purpose is non conductive

pale umbra
#

saw a boat where the coating had flaked off and at some place the boat was almost transparent. Was a weird experience

#

Like an inverse periscope

hushed blade
#

Yeah, there are more and more "art" boards being made and I think there's potentially a market for discussing the fr4 you use in art terms

void sentinel
#

They put circuits right into plastic ribbon cable. And have for a long time

hushed blade
#

My next PCB order I'm planning on having a small section without copper or soldermask to test how translucent it is for my manufacturer, but since they don't talk about it I assume it's technically subject to change without notice

void sentinel
#

What is the functionality of the transparency of the board?

hushed blade
#

to have the pcb be visible in the final application and a light behind it.

#

far more on the art side than the practical side, admittedly

void sentinel
#

Aesthetics?

pale umbra
#

I thought you were going to say something very exciting like "to catch neutrinos"

void sentinel
#

Ok nice

knotty tiger
#

some quick searching shows most transparent PCB manufacturing services are using some kind of polymer flex-PC substrate, glass, or ceramic, but not FR-4

void sentinel
#

Art doesn't have to be just in museums. If people were proud of their things, their things would be nice to look at.

pale umbra
#

Don't know if it count as art but I'm making a workbench out of empty prime boxes

#

Small apartment so I have to maximize the slots in my bag so to speak 😄

#

When you can't have more bags you put more things per bag

void sentinel
#

I just get more bags. Try Amazon. Lol

distant raven
hushed blade
#

I'm not sure argon, I'm going off of not much more than some google searches, what I'm finding might not TECHNICALLY be fr4, though it does come up when searching for fr4

distant raven
#

There is transparent PCB, it’s just really expensive lol

#

And transparent PCB generally is pretty application specific. It’s not ideal for a lot of projects. Mostly focused on lighting/optics/high heat functions

hushed blade
#

Yeah, I wouldn't need completely transparent. I want just good enough to see the backlighting and be able to print silkscreen over it because you can get way more detail out of silkscreen vs putting holes in an opaque board

#

and can have disconnected areas

pale umbra
#

If your light is strong enough transparent or not doesn't matter 😄

#

Like my bike light goes throught my hand

knotty tiger
#

i don't know that you can have an epoxy that's index-matched for transparency and still meet all the other FR-4 specifications. maybe, but if it were possible, i would think that someone would be selling it

void sentinel
#

Oshpark has a flex option. See what they use for that. It would have cost me 43 to go that route instead of 21.50

#

So expense seems to be the word

hushed blade
#

I've seen someone (forget who, sadly) who got every pcb option from jlcpcb and ran a light behind them. Some of them (i remember the red specifically) showed light pretty nicely

#

you can get decently translucent already, it's just that no manufacturer puts that in writing so it's hard to know without just ordering to see

void sentinel
#

Of course switching to rush would have doubled it too, so not sure of their system.

#

Maybe just a brighter light source? Lol
Change of perspective

hushed blade
#

it's ultimately a problem of scale, probably. they are trying to combine multiple customers orders to fit efficiently on a fixed size plate. the more customers you have a time, the more likely you are to find a perfect fit

#

and rush means they have to put you on a plate before they can necessarily find that perfect fit, meaning wasted space

void sentinel
#

They have a tutorial on the motorized slider potentiometers.
Those things are sold out every time I look.

pale umbra
#

mouser and digikey have a model in stock atm

#

64 / 267

knotty tiger
pale umbra
rustic fulcrum
hushed blade
#

Usually it's so that your electronics can be fairly simple in concept (it's "just" a potentiometer) but you can add fun features like saved settings

pale umbra
#

Do they connect to standard knobs anyway? Or it's just for the backend inside a panel/enclosure ?

hushed blade
#

audio mixers use it so save settings and be able to return to them at the press of a button

pale umbra
knotty tiger
rustic fulcrum
pale umbra
#

these are the ones I meant, except mine consume scrap ICs

hushed blade
#

oooh yeah, lighting control boards I don't have personal experience with, but it makes sense they would have almost identical needs to the audio mixers

pale umbra
#

like just because the board is dead doesn't mean all the ICs are, some still contain their magic smoke

rustic fulcrum
#

Just realised that they could also potentially be used to make little indicator displays that only use any power when changing what it's set to

#

Like very simplistic physical e-ink heh

pale umbra
#

so you can use a servo to crush them on command and crush them to release the smoke on command 🤣

hushed blade
#

yeah, linear actuators tend to be pretty expensive and too overdesigned for some uses. I bet there's some subset of uses where those are the most economical solution to just linear motion

pale umbra
#

if it's motorized enough it's a cheap way to produce linear motions on the attached operator 😄

#

like if you want to make an electronic that is scared of humans and throw them away when they try to operate it

rustic fulcrum
#

there really should be a term for when you're about to make an order for parts and are trying to work out if there's another stuff you should get while you're at it

pale umbra
#

I call it packing my order with deadweight 😄

#

"Don't kid yourself 5$ oled, you are just there so I don't pay 50$ in shipping"

rustic fulcrum
#

oh I'm gonna have to pay for shipping regardless, but Pimoroni have a big sale on

hushed blade
#

adafruit is really good at eliciting that feeling. I have so many uses for rp2040s that I tend to go for that tier, then once I have that much, free shipping is right around the corner...

rustic fulcrum
#

mumbles something about a 10% off coupon code he knows about for Adafruit

#

though I guess that'll make it even harder to get free shipping so you'll need to order even more 😉

hushed blade
#

it's never ending!

#

but I don't mind, because I get cool stuff

pale umbra
#

I'd like motorized switch personally for permanent memory

#

still need a countermeasure against the user (like shock) if they try to prevent the circuit from physically changing the switch position

void sentinel
#

Hey everyone. Now that I see my chip is not around and I ordered my boards, what are my next options? It was an ATSAMD21G18...

#

Do I take the loss and switch my board from the G to the J? ATSAMD21J17D-AU
or can I get them somewhere else? I mean if digikey doesn't have them...

void sentinel
#

the samd51 and the samd21 are like the same price. lesson 3042 great.

hushed smelt
#

It happens, sucks bad when it happens but it does happen. Sorry to hear that. 😦 You're going to have to redesign the board anyway most likely so which chip you go with is completely up to you and your design goals.

void sentinel
#

Maybe I should switch to the rp2040?
You know, for my first smd... Lol

#

Suggestions? I guess I will get to work on the reflow oven. The good thing is my boards are on a panel with 47 other projects and they should get it back Sept 8.
I am thinking I can get 3 samd21g18 from somewhere maybe 5. I expect to mess up.

Come on, who has a couple?

distant raven
#

RP2040 might be tricky for your first SMD with its 0.4mm pitch

void sentinel
#

Ha, tricky and not finishing what I start, are all middle names of mine

#

I was designing in my brain a circuit board that would solder onto the place where the samd21 should be and break out the needed pins to something else. My qfn breakout board lol

#

This project was going to start with a mega328 or something but I got a trinket m0 and a feather m0 basic proto and i can only program 1 thing at a time.
I have been bouncing back and forth with c and python

distant raven
#

You can back order from Digi-Key

void sentinel
#

I haven't even written any real code. It was slightly modified from the original arduino tutorial

distant raven
#

Says they have some coming in stock in November

void sentinel
#

They have like 43,000 on back order

distant raven
#

Do a back order now and it will ship when they arrive

void sentinel
#

One of them did lol

distant raven
#

Back order date given means that subtracting all other back orders, there will be some available on that date

void sentinel
#

I can't wait that long. A new thing will just happen instead

distant raven
#

In this case, Digi-Key says Nov 21

#

3 in stock and only $18 a piece

#

Or how about going the ESP32-c3 route and referencing this Adafruit QtPy ESP32-c3?

void sentinel
#

Those are 18 bucks each. I could just buy something else and reflow the chip off for less

distant raven
#

They you get RISC-V, WiFi, BLE

void sentinel
#

Adafriit has 2040 for a buck a piece. I am pretty sure that is my new potential chip

distant raven
#

0.4mm lead pitch is not very first time friendly.

#

It’s a great cheap chip, don’t get me wrong. I’ve made tons of rp2040 boards myself

rain remnant
#

the ESP32-C3 can be very small

void sentinel
#

I has esp-cam boards for like 10 each.
I have a rover break out.

#

That is supposed to be the next gen (wireless)

distant raven
void sentinel
#

This is going to be rs485 differential signaling for 200ft distance with potential rf noise

#

Eh my learning curves are very sharp

distant raven
#

0.5mm QFN is much easier to solder

void sentinel
#

I mess up the bell curve and all the kids hate me

#

I am making up for lost time.

distant raven
#

Sure, that’s fine and all. Are you using an rs485 translator?

void sentinel
#

I learned eagle and ordered my first board in 2 days

distant raven
#

Since voltages are well above what most microcontrollers can handle

void sentinel
#

Max485 chip

#

Maxim

#

Ttl to balanced line

#

It seriously communicates serial with rx tx

#

It is so basic

#

The mcp is an i2c

#

Thermocouple amplifier

#

All it needs to do is read a temp when called on. Like a good little device that does what it's told and follows directions

distant raven
#

Gotcha, makes sense

void sentinel
#

An uno asking these other processors for their data.

#

ANY processor is overkill.
But it needs one of em

distant raven
#

Gotcha

void sentinel
#

This is actually the test unit for the next evolution.
I decided the I want it to be 2.8" or 3.5" instead of the esp32tft

PXL_20220831_123840692.jpg
#

That connects to wifi and sends data to a server of mine. And datalogs locally of course

#

Then I added a section that uses ajax to grab the latest data and plot it on a web page I made to organise some of the other furnace stuff.

PXL_20220831_124012238.jpg
#

So These things I am actively working on are like entry level dummies. Real simple one task.

#

Potentially upgradeable

#

We all know (other than finding chips) the real magic is in the software.

#

We can buy a webcam for 10 dollars and throw a few hundred lines of code somewhere and that thing can recognize objects and motion, it can tell if you're lying (depends on the code...) Whatever...

tough matrix
void sentinel
#

It was qfn lol

tough matrix
#

:(

void sentinel
#

I didn't research. It's my bad

#

I started backwards this whole thing. Failing helps you learn way faster

#

The fancy nerds just call it iteration

#

Makes it sound intentional

#

That's why I like to think I will fail. And I try to figure out how before it happens.

#

Of course there are always unexpected variables.

#

Insert an excuse for ignorance. I can't know what I need to know until I need to know it.

#

At that point I either know it or...

tough matrix
#

or you can order one last chip from lcsc for whopping $15 + shipping

void sentinel
#

It comes with extra parts...

#

Oh they only had 1 in stock anyway lol I need 3 or 4 at least. I am picturing 5 for somewhere between 25 and 50

#

They don't even have 32u4 in stock. See it's like the world is forced to evolve.

void sentinel
#

I never got into the attiny or pics or that propeller chip. That was the generation before Arduino basically. Like 20 years ago it seems.

woven bluff
#

I don't even consider QFN for hand solder... you can not even stick a probe on it if something goes wrong.

distant raven
#

Sure you can, you just need needle probes

#

Get yourself a kit like this Bionso 25-Piece Multimeter Leads Kit, Professional and Upgraded Test Leads Set with Replaceable Gold-Plated Multimeter Probes, Alligator Clips, Test Hooks and Back Probe Pins. https://a.co/d/4qAshGL

woven bluff
#

I have this design I wanted to send to fab half a year ago, but every time I open it I can find something to improve...

light prism
#

I need a quick and dirty way to power a project from usb-c. 5V ~50mA is all i need, but I need some kind of short-circuit protection. (power is being supplied to pogo-pins that can easily be shorted). any thoughts?

woven bluff
#

I would use a power switch IC

#

if you want to keep things simple, just use a fuse

light prism
#

maybe I'm over thinking this and should just put a small resistor inline to limit the current to like 200ma?

woven bluff
#

depends how much voltage drop you can tolerate

light prism
#

fair - this is feeding a bq25100 battery charger ic, which has a min input voltage of 4.45

#

time for some maths

#

i guess it works out then that a ~10ohm resistor would give me 500ma in a short situation, and about a .5v drop at 50mA charging.

#

seems borderline though

woven bluff
#

be aware there's already a short-circuit protection in usb host controller, it may trip at 500mA.

rustic fulcrum
light prism
#

it does seem like that is what i want - but is there a way to implement that quickly? i don't have time to get a board made

#

looking for an inline option or something with a breakout board that already exists

#

looks like TI may have some evaluation boards that could work

rustic fulcrum
#

Looks like there's some through-hole ones too

light prism
#

i'm a mechanical engineer wearing an EE hat. That looks scary to me

rustic fulcrum
#

woah

#

that's a very expensive and huge way of doing so

#

hang on

light prism
#

i have budget and space. I wouldn't mind saving some money, but time is probably the most important thing here

rustic fulcrum
#

Assuming that all the extra things it can do don't get in the way, these are available as through hole

#

oh the link blocking bot is not my favourite thing

light prism
#

i gotta run for now but will give that a look through in the morning. thanks for the help

rustic fulcrum
rustic fulcrum
# light prism i gotta run for now but will give that a look through in the morning. thanks for...

Yeah, I think that's a better plan. Combine a SMT breakout https://www.adafruit.com/category/475 with an actual eFuse chip that's designed for this. You could also possibly use the magnetic connectors instead of your pogo pins, which are magnetically polarised so you have to somewhat fight to get them the wrong way around, or possibly change the design to make it harder to physically do it otherwise? I also just discovered that RS Components will actually ship to the US, albeit with pricier shipping and import tax. If you've not come across it, Octopart is quite handy to to search for stuff across retailers: https://octopart.com

woven bluff
#

I'd opt for power switch IC, they are cheap and come with all sorts of protections

#

e.g. TPS2049DR

rustic fulcrum
# woven bluff e.g. TPS2049DR

Think these would work? I'm getting confused by the different SMT package names versus the breakout Adafruit sells, not sure which if any would be compatible: https://www.digikey.co.uk/en/products/filter/power-management-pmic/power-distribution-switches-load-drivers/726?s=N4IgjCBcpgbFoDGUBmBDANgZwKYBoQB7KAbRABYAGAVnICZyQCraBmapim8qkAXQIAHAC5QQAZWEAnAJYA7AOYgAvgTDq6CEMkjps%2BIqRCxKPCATqU6ADgDsrTmFvUw5CAJAixk2YpVrrMGstHT1cAmJIMlZ2AE5qYIIY6liTTlhrOhdzEGTUxiS423hClNtbTjzrSk5ye1pEkGpnSnZa6tjXSszMgtyeuu6bWA4kzNjTIYnR-rpYuhyqBcmPL0gJaXklVRAAWk1obShpAFcDSLIZ2P5lW6A

https://www.adafruit.com/product/1230

distant raven
#

12.5W max rating is pretty stout for $0.65

rustic fulcrum
distant raven
#

I didn't claim it did, I was just chiming in with a load switch i've used and like

rustic fulcrum
distant raven
#

you could get short circuit protection with a PTC

#

depending on your needs and anticipated power source, you can choke it at 500mA, 1A, up to like 280A lol

pale umbra
#

"allowing just enough residual current flow to maintain the block’s internal temperature at 125C" cool it can boil water for my coffee!

distant raven
#

🙂

void sentinel
#

My new 2040 collection

PXL_20220901_050459975.jpg
void sentinel
#

They are tiny... that is a needle tool I have and my smallest iron tip. but according to legend, I would want to reflow this in an oven or maybe on a plate and or with a hot air gun. Not with an iron. If that is what was meant by hand solder?
Not saying I can do it. I am just mentioning that I might also have a microscope. So at least I can see all the shorts...
and who knows, ok you know who you are, maybe I can solder wick it off lol

2040qfn0.4.png
hushed smelt
#

oh i'm using that pic for my github

#

i have a hw design problem maybe someone can help with. i'm using an RP Pico with MCP23017 gpio expanders. Unsure what to do with the interrupt pins.

#

I've seen some diagrams online that chains each expander to each other and 3v3 with a pull down resistor. That just seems odd to me.

#

interrupts are on U5 and U6 inta A & B each.

#

breaking them out to pads right now just in case because i'm not sure if they're required or if they are how to wire them up in this scenario.

#

wouldn't it be better to run the interrupt lines straight to the Pico and let the Pico's GPIO handle the interrupt to both of them individually instead of daisy chaining them?

void sentinel
#

that is a neat chip. i thought the interupts were input. they are configurable to potentially be triggered on change of the GP inputs so I guess each chip could be 2 different 8 bit inputs. But what do you WANT to do with them? I am guessing you were just using u5 and u6 as pass through expanders? so you have bonus hardware to write code for? or to not... lol

#

analog bits too

#

not sure how they get used when you have in and out on the same channel

#

nevermind the analog bits are the address

#

I cleaned my tip...

cleaner.png
hushed smelt
#

think i figured out the interrupts yeah. as far as i can tell they're unnecessary if i have enough i2c busses for each. the pico has 2 and i'm only using 2 expanders. i think interrupts would be more handy if i was doing something Liz Clark's xylophone and had like 8 with some needing to be daisy chained.

#

moved some of the SPI pins and other stuff. think it's just about cleaned up now.

#

added a reset button too because it's a pico.

#

i might add jump pads for the expander reset too just to be safe in case it might need a resistor

#

expanders are just a way to add 16 step switches. pico alone doesn't have enough gpio.

#

interrupts being inputs makes a lot more sense. if i run them to pico gpio then i can control interrupts from software, hopefully that'll work.

#

i don't know if they're necessary in my design, yeah it'll be an additional feature hopefully unneeded. i'd rather not have to deal with interrupts in the design if possible, interrupts i feel like would just slow it down.

dry jetty
#

Not sure this is a HW question: I did a design blunder - and now I have to find a way to use a digital pin for measuring analog. From my days with Parallax/Propeller I remember a way where the analog in charges a small capacitor, the digital pin is set as output with a 'zero', quickly disharges the capacitor, then it is set as input and measures the time it takes to recharge the capacitor (dependant on analog in signal level) to the level when a 'one' is detected. This enables a (crude) calculation of the AI level. Is this feasible/done on a Feather M4? It's only for an LDR, so accuracy is not imporant.

knotty tiger
knotty tiger
outer adder
#

Hello,do anybody have any idea how cound I implement hot-plug in MCP9808 sensor in SW and HW.Thanks in advance

light prism
#

@woven bluff thanks, TPS2049 is exactly what I was looking for!

void sentinel
#

Do you have a breakout board? I2c? How are you using it?

#

I mean I know it is i2c I am just like wondering why it is unplugging and all

dry jetty
outer adder
void sentinel
#

Why is it unplugging?

outer adder
#

its is not unplugging,but how can it be implemented in hardware hotplugging.What changes should a do,in HW part firstly in difference to a normal connection.MPU is a RPi.I a beginner maybe Im saying smth wrong

void sentinel
#

It sounds like you want to write code for something that you aren't doing?

#

What language are you coding in?

#

Hot plugging is when you plug or unplug when the connection has power

#

You said you are not unplugging. Which is it?

outer adder
distant raven
#

Basically pulls the lines up before connecting them. Used for hot swapping

outer adder
#

its not possible without a terminator?

distant raven
#

You run the risk of a fault of the buses are connected at a bad clock interval causing you to have to reset the board

outer adder
#

understand,thanks for the advice

rustic fulcrum
# outer adder its is not unplugging,but how can it be implemented in hardware hotplugging.What...

I think this is probably the board you want, the one @distant raven suggested is great if you want to make them work on super long cables, but this is explicitly to enable hot swapping: https://www.adafruit.com/product/5159

Adafruit TCA4307 Hot-Swap I2C Buffer with Stuck Bus Recovery

As we've been adding  STEMMA QT connectors to our breakouts and dev boards, folks have been really enjoying the simplicity and speed of plugging in I2C sensors and devices for quick ...

distant raven
rustic fulcrum
#

I do keep being tempted by the LTC4311 tbh, one of the projects I want to do is an outdoor temp/humidity sensor, and all of the power issues, and to some extent, some of the waterproofing ones, go away if I can just get a cable outside which attaches directly to the sensor board.

rustic fulcrum
#

Can I ask what your project is that it needs to handle the sensor being disconnected without being reset @outer adder ?

rustic fulcrum
#

Does anyone know of a service that'll make a super basic breakout board for a SMT chip you send them? Adafruit make SMT adapters for a few chips but only really the larger ones and even their pins are teeny though that I'm not sure how likely it is that I'll be able to successfully solder them. Keep thinking it'd be an awesome service for someone like Digikey to partner with someone to offer.

distant raven
rustic fulcrum
distant raven
#

JLCPCB would

#

And PCBWay

rustic fulcrum
distant raven
#

Lol

rustic fulcrum
#

I still can't quite figure out if that voiceover is a real person or text-to-speech

rustic fulcrum
#

It also took me way too long to realise that PCBWay's quote was telling me that it was the same price to get 50 of them as ordering a single board.

knotty tiger
#

i wonder if there are any standard EDA parts libraries that have SMT-to-DIP breakouts

rustic fulcrum
#

Hmm, how feasible might it be for a noob to get the super mini hotplate and just order teeny PCBs and then actually put parts on there myself with paste (?)? I have no idea how any of this works

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Or would I need a custom stencil for the paste?

knotty tiger
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i thought i've seen retail solder stencils for common SMD footprints

distant raven
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Long link but that’s a common part stencil

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It’s for a kit but you could totally use it for other things

rustic fulcrum
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hmmmmmmm

distant raven
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Digi-Key had a whole lot of stencils

rustic fulcrum
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so I'd design a breakout board for the part/see if I can find a premade one, order it from someone, then get the stencil, place it over it, brush (?) solder paste over it, carefully place the chip on it, pop it on the teeny hotplate, heat it up, then cool it down, and then that's that?

distant raven
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Yup

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The stencil part takes a little practice but definitely fairly easy to get the hang of

rustic fulcrum
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though I guess admittedly the chip I wanted isn't actually in stock anywhere. Is there a chip shortage? 😉

distant raven
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Chip shortage? Never heard of it

pale umbra
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nah the slves were full last I looked especially plain and bbq

void sentinel
void sentinel
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it seems like we are heading down a similar path

rustic fulcrum
void sentinel
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I have a device I started as a nest thermostat alt. It was really to replace an existing thermostat that had a broken wire to the up button on the plastic ribbon cable...
As it started to evolve, I got the esp32-s2 and started working on a different datalogger/ display/ almost controller...
I stopped working on the basic unit and realized what would be cool if I had the MCP9808 and the MCP9600 even thought the hot junction on the MCP9600 is similar to what I would get from the 9808, I wanted dedicated chips. And I wanted it to switch through software not hardware... I had thought of hotplugging, but that isn't needed really.

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right when I was like, "ok this works. lets print an enclosure" iterating happened. It never stops. I have change issues...

rustic fulcrum
void sentinel
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anyone familiar with 4-20mA control loops? circuitry? These are usually 24vdc. not necesarily, but in my case that will be the design. basically a 5k pot in series with 1k ohms could do the job. But I want software control not a pot...
It's the output my controller needs to um control things.

knotty tiger
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you want to somehow output a 4-20mA current loop signal from a microcontroller?

knotty tiger
# void sentinel anyone familiar with 4-20mA control loops? circuitry? These are usually 24vdc. n...

i found these with a quick search; haven't investigated thoroughly https://www.maximintegrated.com/en/design/technical-documents/app-notes/6/6508.html
https://www.ti.com/lit/ds/symlink/dac161s997.pdf
is your board being loop-powered? or is it providing loop power?

How to Implement a 4-20mA Transmitter wit | Maxim Integrated

How to use a highly configurable analog front-end for 4-20mA sensor transmitter.

void sentinel
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dang that is a 32 pin qfn or whatever

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it is integrated. but dang. I have been researching the op amp circuitry involved in the measuricating

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Yup there is the magic:

voltageToCurrentMagic.png
knotty tiger
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yeah, a current-sensing op amp with a hybrid analog/digital feedback loop wrapped around it might be a way to homebrew one

void sentinel
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I actually bought one of these: https://www.amazon.com/gp/product/B07BDJJNK3
a while ago and it is very simple. I just wasn't sure if anyone here was into that sort of thing and would have refined something.
I mean besides maxim and microchip lol

NOYITO Voltage to Current Module 0-24V to 4-20mA

Features: Using single-chip embedded technology. Implement the industry standard voltage (0-24V) into an industry standard current (0-20mA, 4-20mA). Linear output, output signal can be directly connected to the AD converter. Can be connected with a microcontroller with AD function. Easy to operat...

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Uses an LM224 from ti

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and a npn transistor for the power like that q1 up there

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BCP56

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it's fun to brainstorm here

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I can't wait to put a drop of nail polish on a pot. I'm usually breaking them off...

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I wanna be like open source Honeywell/Yokogawa (I don't)

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That is funny because in the 90s I did audio video security for auto and commercial/residential. Before I got into ADT type of security stuffs the car audio was my thing. I was the one that made the cars go boom... That was also around when I was schooling so I really did want to be like Alpine and Bose. crazy magic sound waveforms and to imagine installing a system in a car where the head unit says your name and the amps have your symbols on them? That is what I wanted.

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It is quiet here at night 😉

supple pollen
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Heh, I was in the Kenwood/Pioneer/Sony camp.

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Having become disenchanted with Blaupunkt after they seemed to lose their way.

void sentinel
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that was entry level. like the jensen 200w everyone had one of them with some 6x9s

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because who cares about physics and soft cones

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I still have a pair of 10 solobarics in my basement

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talk about physics ha

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Orion was one of the best speakers I hooked up one 18" in a honda civic.

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spl was way way up there

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I could just throw that in a pile and have noise. I mean sound.

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Alpine had those units with the 6 green buttons. Those were the very best for years. Pretty much until navigation came out.

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There were some rare ones that no one could afford like Harmon Kardon. Those weren't around much though.
Around then is also when auto manufacturers started partnering with audio manufacturers.

rustic fulcrum
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Huh, I just had a terrible idea. I wonder if it might be possible to buy an Adafruit breakout board with a chip on it that's the same package as you want, pop it on a teeny hotplate, pop the existing chip off, and then replace it with one you want a breakout for

void sentinel
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it is. and if adafruit doesn't make it, sparky fun time probably did.

woven bluff
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or hot air with QFP nuzzle

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or hot air on the back side

void sentinel
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Look at this mess...

redo.png
woven bluff
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that's what happens when you add stuff to the schematic. I don't think any EDA software has automatic placement

void sentinel
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It looks the same lol. red lines green lines black text

redoSch.png
void sentinel
woven bluff
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any idea on human presence detector?

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I tried PIR, but it won't work if I remain still.

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and amg8833 breakout board is too big to fit in my project

supple pollen
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Clever use of the double decimals as colons

outer adder
outer adder
void sentinel
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Other than scanning temp sensors pir is funny. i used rf blankets to detect motion. The thing is, presence and motion are different. do you have entrances or exits that have to be passed? beam break, door sensor, pir on two sides of an entrance. pir just isnt good for anything but certain motion. Image object detection is making that obsolete I feel. Nothing like a good old yawcam or whatever. Even espcam stuff has object detection codes laying around.

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a lidar could paint a map then scan for new objects. expensive though

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i vote with timer after pir detects. just like motion sensing lights work...

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what is it for? lol

cunning hull
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specially interested in how slim it is an the rotay enc with a button in the middle

void sentinel
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I saw that and I forgot to buy it. grrr. thanks though I can add it to my cart

cunning hull
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out of stock 😅

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thats why i want to build it, to hve some thing like it and learn to build a piece of hardware

void sentinel
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at the bottom of almost every product is a link to the learn site

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and they recommend you buy the break out. It looks pretty simple. But fancy

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and with that neopixel ring, perfect

cunning hull
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yeah how to use it but not how to build it, i spcially want the really slim rotary encoder it uses, cant find a similar piece online

void sentinel
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what do you mean how to "build it"

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the actual encoder?

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and the buttons

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in a plastic housing? all that?

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look up how encoders work. there are a few kinds the ones I just bought are quadrature style. they have 2 switches whos oututput is a square wave 90 degrees out of sync

cunning hull
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yeah, at lest get that nice slim wheel encoder it uses and i can build the rest around it

void sentinel
cunning hull
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that piece but slim would be perfect

void sentinel
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actually the best would probably be the thumbwheel to have slits in it and have photo electric sensors (2 of course) detecting the slits. that could be pretty compact

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you could even have the pattern on the underside with the sensors reflecting off the pattern instead of the beam break way

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I mean if you are going to "build it" yourself...

cunning hull
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hey thats not a bad idea, i havent thought about approaching it that way

void sentinel
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are you familiar with the balls in old mice or trackballs the way they work? or capacitive touch screen they have round ones. people make watches and all kinds of things with them

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a pseudo rotary encoder

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imagine walking up to the super secret spy gate and there is a coin slot, but the coin only goes in half way and it rotates something and there may be holes or special reflective surfaces or embedded chips like rfid

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oh oh

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hall effect sensors

cunning hull
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so much to play around with, so little time

void sentinel
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rotary encoder with hall effect sensors. that might be really easy

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I love choices. I spend all my time choosing and not doing

cunning hull
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i feel you

vast flume
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Have any of you used Flux.ai for pcb design?

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I just got into the beta for it

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Curious about everyone's thoughts on its current state

pure gorge
distant raven
vast flume
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So I finally got around to testing my hotplate...

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It doesn't work

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The pcb hasn't arrived yet, so I just thermal glued the heating element to the aluminum sheet, but it seems that too much heat is being transferred from the sheet to the air for the aluminum sheet to heat up hot enough

pale umbra
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the sides of it going to be 3d printed plastic ?

vast flume
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Yeah but the sheet mounts to the base through 3" metal standoffs

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So theres an air gap between it and the petg

vast flume
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I'm going to try running 2 50w heating elements instead of 1

woven bluff
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I'm trying to make a plasma arc lighter with fly-back convertor, but I couldn't find compact HV transformer for sell.

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is it possible to make a transformer-less design?

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boost convertor can go 1KV with SiC FET. maybe 10 stages of voltage multiplier after that?

supple pollen
knotty tiger
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large voltage ratios are more efficient to achieve using inductors or transformers; i think capacitor-based solutions end up being too lossy for any substantial current, though i forget the exact reasons

supple pollen
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I think that's why they're proposing a boost converter followed by a multiplier

knotty tiger
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oh ok, maybe i misread somewhere that they were asking about a switched-capacitor converter somehow

supple pollen
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That may have been the other thread about LCD contrast, I dunno

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Amusingly, I'm looking at a switched capacitor converter to boost 9V to 25V for another project.

pale umbra
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Saw a 1200W (25V to 240V) power supply yesterday for different uses (computer, lab, etc) I bet it would light my LCD up really well in every meanings of the word 😄