software requirements are a facet of software engineering i wasnt very familiar with before working in the field. it was hardly mentioned in school. turns out they are more important than the software itself - at least where i work. i dont see them taken very seriously in open source software either
#general-tech
slim silo
plain dagger
as ardnew pointed out, its harder on learning/personal projects. those don't generally start out with defined requirements...
thick prawn
Indeed
Well, I learned about TDD from Robert C. Martin
So, you might be able to guess the kind of person he is to take it incredibly seriously
Seems like a very professional and clean thing to do properly
plain dagger
Uncle Bob is def a believer. 😄
thick prawn
I love that man
His books are just awesome
Punching me in the face every new chapter I read. He makes too much sense
But I'm disappointed that I can't apply what he's teaching me as simply as he makes it look
Really makes me beat myself up when I try
He completely changed the way I think about myself as a developer, and so early in my career, too. But every time I've tried to apply religious testing like he does it, I flop, and I flop hard
Because the type of testing he demonstrates in his books...it's very "vanilla". Testing a string parser class, for example. He doesn't get into making towers of mock objects, like I have to do
buoyant lintel
I think the idea is that if you have to make towers of mock objects, the code you're testing is badly written
inner linden
I dono, I think of Robert C. Martin as a snake oil salesman.
Like, why should I call him "Uncle Bob"
It's a lot easier to write a book and talk about "Hey, you should write a lot of tests and do TDD" than it is to actually make it happen.
Also, he's a jerk and a transphobe and has actively gone after my friends.
thick prawn
Uhhhhhhh
What?
You know the guy in person or something? Or has he flamed your friends online?
inner linden
He's disliked by a lot of the women-in-tech community for justifiable reasons. I'm being vague on purpose.
So, like, yah, I'm a huge fan of software testing for writing software. I've been part of teams that have written software that was so well tested that it sat running with zero support staff for years after we all left.
My advice on how to make that happen may or may not align with Robert C. Martin's books, but he's a really really problematic person.
desert cipher
does it make any difference if person goes off on homophotic rant in person or online? (not have met guy in person or online but asking) (familyfriendlyname)
inner linden
Yeah, because if a cuddly "Uncle Bob" sort of guy is homophobic than a bunch of junior engineers read his book and think he's kinda smart and decide that if he's able to be a jerk online, that makes it OK.
Like, he's been working in consulting for years, not actually writing stuff, so at this point he's kinda at the motivational speaker level of coding advice.
And most of what I know about writing testable code comes from writing tests for code that's not testable and then asking myself how I can not have to write a tower of mocks or something next time.
As far as I'm concerned, if someone's spending a book telling you to do stuff, showing you a vanilla case, and not also teaching you well enough to apply it to the complex sticky case of real world code, that's puffery not teaching. Because I have had a bunch of lightbulb moments over the years where people did introduce concepts that made testing of real-world complex code easier.
desert cipher
such is good for basic examples for begineer but yeah should have real world examples
inner linden
It's really really hard to figure out how to condense an aspect of a real world problem down to something that will fit into a book. That's why there's so many bad CS books out there, because it's easier to write a tome of puffery that doesn't hold up to reality.
mental mica
tbh, the lack of documentation for arduino features like this is really frustrating sometimes
I remember a past project where I was trying to set a PWM frequency of an Uno, and the only source of info I could find was an obscure forum post— not a datasheet or documentation
glacial crater
Why is it so hard to turn a dumb sketch up file to something 3D printable. All I want is a tiny little tikes cozy coupe. 😭
meager wraith
Hey I need urgent help here
I am trying to install Mpv based on the post on Raspberry pi official website
Idk what's happening and it's failing
This is my code that I use which is exactly the same as the one listed on the website
I am using a new Raspberry pi 3b+ here
serene rampart
I saw an addition to GitHub a few days ago of code for a LiPo single cell battery gauge. https://github.com/adafruit/Adafruit_LC709203F -- this is the one I use in my projects ( for STM32 and for Atmega )
When will the breakout boards be available?
cold pebble
I don't think adafruit pre-announces dates, but they do leave breadcrumbs. It could show up pre-release in the Top Secret segment of Ask An Engineer, or sometimes there are #LEEKS here, or sometimes it just gets mentioned somewhere random.
grim leaf
anyone want to join my project
proper escarp
@grim leaf do you want to describe your project first?
grim leaf
yes
this is a ai which also has a hard ware
you can think it is like hey google hop in my server i will give more in for mation
are you intrested
buoyant lintel
Are USB-C cables generally active, or passive? I'm thinking of using them to power my project by just connecting to the pins on a barebones USB breakout, because a conductor is a conductor. But the protocol includes things like advertising the amount of power it can handle, using the CC pins to determine the mode, etc
And I don't know how much of that is happening in the cable or in the socket
I could tear down a cable, but that only tells me about the one cable
hearty karma
I suspect @slim silo might be able to answer that, given the amount of research they've done on USB-C PD.
My guess (which is only a guess) is that most of the wires are simply that: wires, but some cables have the "electronically marked cable" circuitry as well for additional functionality, which would likely not affect your use case but I don't really know.
grim leaf
yes
what webinar
the webinar is not ready yet but ypou can join my project
one sec
here my sicord link
pine igloo
@meager wraith Might try posting you question in "#help-with-linux-sbcs" 🙂
wicked matrix
It's not permitted to share discord links due to spam.
pine igloo
@buoyant lintel USB under 16' (5m) are usually passive. They fall into the spec not needing help to provide a clean sigal and full power. USB2 spec
Over that length requires amplification and, in a good cable, filtering which adds some circuitry to the mix making them active.
buoyant lintel
Perfect. I'm not going over 1m
pine igloo
@wicked matrix I understand, it was not intended to be a link. Will show more care in the future. 🙂
proper escarp
@pine igloo this is true for USB2
for USB_C, "USB 3.1 cables are considered full-featured USB-C cables. They are electronically marked cables that contain a chip with an ID function based on the configuration channel and vendor-defined messages (VDM) from the USB Power Delivery 2.0 specification. Cable length should be ≤2 m for Gen 1 or ≤1 m for Gen 2.[9] The electronic ID chip provides information about product/vendor, cable connectors, USB signalling protocol (2.0, Gen 1, Gen 2), passive/active construction, use of VCONN power, available VBUS current, latency, RX/TX directionality, SOP controller mode, and hardware/firmware version.[6]"
pine igloo
@buoyant lintel Excellent. Have a fine day.
proper escarp
so they are not just passives
buoyant lintel
Right, but if the chip is just for the benefit of the host and doesn't stop me from putting whtaever signal on the pins I want, then I can ignore it
proper escarp
@buoyant lintel probably so
pine igloo
Seems to be the case, I stand corrected 🙂 Thx!
Wikipedia is so good.. <grins>
buoyant lintel
sounds like I'll need to test to make sure, but it's probable that I can use the cable the way I want to use it. awesome
meager wraith
@meager wraith Might try posting you question in "#help-with-linux-sbcs" 🙂
@pine igloo Yeah thanks for the tip
See you in raspberry channel then
buoyant lintel
Anyone have good ideas for labeling ICs once they're on breakouts? I always forget what they are when I don't have a magnifier handy
inner linden
Permanent marker works well if you have lighter-colored breakouts.
static stream
I use paper price labels, you can easily remove them if you need to
meager wraith
Would be great if I could get more help in #help-with-linux-sbcs
buoyant lintel
Oh good idea about the labels
mental mica
In PC building, it's been said that it's bad luck to put the side panel on until you've seen it boot. I'd like to propose that the MCU equivalent is removing Serial from your code.
I dunno how common this is, but I so frequently use Serial.println(some var) during programming, that removing the Serial class is part of "final cleanup" in all my projects lol
real scarab
The fun bit is when removing Serial breaks the code.
mental mica
That sounds like a terrifying/frustrating bug to hunt
real scarab
Serial.println is relatively slow, so it affects the timing of your program. Timing bugs are the worst!
slim silo
@buoyant lintel it really depends on the USB-C cable you have, AND which wires you're referring to. by and large, if you are using a USB 2.0 Type-C to Type-A cable, then only the traditional VBUS, GND, D+, D- cables are actually connected from one end to the other. the Type-C connector will also have the little Rp resistors built into the connector, but this only matters on the off chance you are plugging the Type-C connector into a USB PD capable supply, as this is what tells the PD supply to output the typical 5V/1.5A-3.0A power (bypassing an active PD negotiation). In either case, the 2.0 pins I just mentioned are passive wires just like if the cable wasn't Type-C at all.
buoyant lintel
What if it's a true USB C cable, not a 2.0 in a C form factor?
slim silo
what sort of breakout are you using?
if it is USB 3.0/3.1 Type-C to Type-A, then again, the cable is not capable of performing PD negotiation (it must be Type-C on both ends). in this case, the Type-C connector will have those same Rp resistors and outputs nominal USB voltage like i mentioned for the USB 2.0 case
buoyant lintel
Plain breakout that just exposes the pins (which is how I'm planning to use it in the end anyway )
I just want the wires to carry current. That's it
slim silo
if you have Type-C on both ends, and it is a true USB 3.0/3.1 cable, then you will have to pull those CC1/CC2 lines to ground via 5.1K resistors on that USB breakout you have
buoyant lintel
USB-C is appealing for my project solely because of the physical form factor
Ok, that's not a biggie
slim silo
A breakout like this?
buoyant lintel
Yep
slim silo
all of the Adafruit Type-C breakouts already have the Rp resistors on them (unlike this)
buoyant lintel
as far as I can see, it doesn't involve any pulldown resistors
I'm using a random ebay breakout
but I mean, if resistors are the only issue, I'm fine regardless
I can slap the appropriate resistors on there if necessary
I just want to make sure there's no negotiation going on within the guts of the cable itself that will stop me from just sending current on arbitrary pins
slim silo
yeah, if youre just needing 5V/3A, then the only thing you would EVER have to ensure is the existence of those pulldowns
buoyant lintel
I'm using it to send PWM signals to my LEDs; no USB negotiation on either end if I can avoid it
I wanted an alternative to a ribbon cable that was something I could plug in behind my back for a wearable, and smaller
seriously, I do not require ANY features
slim silo
cables won't ever do negotiation proper, they just detect termination and orientation
buoyant lintel
Gotcha
reading up on hte USB-C protocol, I was kind of worried that if I didn't send some signal on the CC port it wouldn't let me transmit over 500 mA on some arbitrary other pin, or whatever (that's a completely bogus example but you get the idea)
so, the cable itself does do some stuff, but the stuff it does is passive and at its most complex involves a couple resistors
right?
brb but I'll be back in a few minutes
slim silo
well im not real certain the capabilities of the active circuitry in cables, but all of that functionality is moot so long as you tie the CC lines to ground with proper resistence
buoyant lintel
"does the cable do anything other than house conductors" is my real question, I think
slim silo
yes, if it is a full-featured Type-C cable, but im not sure what exactly
buoyant lintel
If i can get it to behave like a dumb cable with a couple resistors, that's good enough for me
oak cove
With active cables resistors on the CC pins will probably not work unless its a really nice active cable with a DAC.
That requires using a USB-C sink controller
But CC resistors will cover most cables
slim silo
if you aren't plugging the cable into a USB PD power supply, then it will be a dumb cable regardless of the existence of resistors
buoyant lintel
👍
oak cove
It will devliver a default power profile, but thats not entirely true
buoyant lintel
And I can transmit whatever I want on any pin?
slim silo
if you use one of the SBU1 or SBU2 pins, you can be confident any active circuitry in the cable will not affect data transmitted across them
buoyant lintel
Awesome
All I want it to do is to be a bundle of conductors with connectors on the enda
*ends
I want to use USB c solely because the form factor is convenient for my project
And it has a decent number of pins
slim silo
yeah, its just that USB-C is a terribly complex confluence of confusing technologies
thats what the "C" stands for
buoyant lintel
Hah
icy moth
Does anyone have a recommendation for 0.05” male jtag socket? I’m only finding SMT and I need through hole
buoyant lintel
are breakouts available?
icy moth
I can make one but ya know lol. I’d rather just buy it
buoyant lintel
fair enough
nothing on digikey? their parameterized search is awesome, particularly if you're only interested in through hole vs surface mount, or whatever
hearty karma
Through hole at that pitch is going to be an oddball.
hearty karma
I'm guessing it's pitch, but I could be wrong
buoyant lintel
You know, it just occurred to me that you can't get decoupling caps anywhere as close to the pins on a breakout/through hole as you can with SMD. I wonder if it's ever a problem? Hasn't been for me, so far, but who knows in the future
the next compoent I'm working with where the cap is important conveniently has a pin SPECIFICALLY for the decoupling cap right next to the VCC pin - well ,at least on the WSON package. So I can drop a capacitor right on the breakout. But noticing that they had a specific pin for it made me wonder
hearty karma
It could be that pin has a different kind of low-inductance bond wire or something for best coupling.
buoyant lintel
(This is the LM3410, if you're wondering)
I mean I was like "wow, that's super convenient, they put them rihgt next to each other!"
but yeah, is it ever an issue, not being able to get the decoupling caps close enough to the pins on components that are attached to a breakout? It seems plausible, and I'm just curious if that's an amount of distance that matters
(as you noticed, I am perpetually curious)
buoyant lintel
aliexpress?
sly violet
Does anyone have any idea why every piece of ILI9341 code I can find seems to swap the column order and the RGB order? According to the docs the defaults should be RGB and origin in the top left, yet everything in existence seems to have to flip those bits.
Like is the datasheet wrong? Or the display manufacturers wiring things up incorrectly? Or every piece of code getting something subtly wrong?
mental mica
I made my arduino dump its FFT data into serial, and pasted the data into google sheets:
I used a (probably inaccurate) tone generator phone app to generate (what should be) a 1050hz sine wave :)
wicked matrix
https://www.adafruit.com/product/2743 SWD breakout, but I think JTAG needs additional pins
slim silo
@sly violet what do you mean by swap column order and RGB order? are you talking about the byte ordering of each? like why is the 16-bit RGB sent high-byte first?
bleak ospreyBOT
Adafruit is now live! join us on https://youtube.com/adafruit/live
karmic obsidian
DESK OF LADYADA - AAA Battery Holders https://youtu.be/FM3ZaN0yvGY
glacial crater
Overture is having an amazing sale rn on 2.85 mm pla. 12.99 a roll
sly violet
@slim silo I mean during initialization they use the Memory Access Control / MADCTL command and flip the MX and BGR bits.
Docs say MX = 0 should start in the top left and BGR = 0 should be RGB order. Yet everything in existence seems to have to flip both of those to actually get top left and RGB order.
My own testing leads to the same thing. Leaving those bits at zero causes 0,0 to be in the top right and for the RGB order to be reversed.
pine igloo
I think I got added here by accident
For all you know I'll be your new best friend
Probably not but maybe
thorny skiff
so i'm watching that stream about the battery holders there... tektronix just sent you a 3104?! i've been hoping to win the lotto so I could buy one and they just mail you one out? That's incredible 😂
charred apex
my math work has a question that says an electrician is using 1.25 feet of electrical tape 😆
who needs that much?
real scarab
I guess it depends on the diameter of the pipe. 😉
harsh venture
I get asked a lot what my development process looks like - here's a thread with some insight into how I develop firmware: https://twitter.com/theavalkyrie/status/1297911069319614464
serene rampart
Well, I just made my own little breakout board for it 🙂
That's meant to be a "shim" board to replace the i2c fuel gauges I have on a project. I'm also making a bigger board with 0.1" through hole pin spacing and a jumper for installation of a thermocouple to monitor battery temps
icy moth
Nice
serene rampart
Yeah -- a real bear to solder them by hand. I have to apply the solder paste using a microdot syringe method
inner linden
@harsh venture I guess you have a firm grasp on things, then.
harsh venture
Firm like tofu
charred apex
god thats tiny
serene rampart
0402's are smaller! 🙂
charred apex
how small?
charred apex
i couldnt do that
charred apex
nah i can barely solder 20 guage wires
charred apex
ima stick with tht for now
cold pebble
At ~$6, this is the cheapest ready-to-go Arduino-able micro with Wi-Fi that I could find. Can't wait for a tiny esp32-s2 for CP.
wicked matrix
I can confirm that practice helps with soldering. Being at peace with the inevitability of destroying a component or board no matter how experienced you are helps too
Pushing your boundaries but not by too much is also good to help grow in a skill
My latest hand soldered surface mount
Lots of room to improve technique, but the board works!
slim silo
@cold pebble good gravy, $55 for that thing? https://m5stack.com/products/atom-lite-esp32-development-kit
cold pebble
that's for a 10-pack
slim silo
oh snap!
charred apex
why are a million people in the voice chat
finite egret
they record an episode that go on youtube
charred apex
oh
vernal garden
It's for our weekly Circuit Python development meeting -- every Monday at 2pm eastern, except for US holidays.
Feel free to catch past meetings on YouTube or your favorite podcast service.
charred apex
what is circuit python
vernal garden
CircuitPython is an open-source programming language designed to simplify experimenting and learning to code on low-cost microcontroller boards.
charred apex
so kinda like arduino?
vernal garden
It's an alternative to Arduino. It's a runtime language versus the compiled language like Arduino, and it runs on a subset of Python.
charred apex
ok
vernal garden
It excels with rapid development and easy of access for beginners.
It does come with the cost of slightly more overhead needed, but with microcontroller processors becoming more powerful, it's a very fair tradeoff for the benefits -- depending on your use case.
for more information, you can go to https://www.circuitpython.org/
Or hop on over to #help-with-circuitpython 🙂
icy moth
Super exciting, my Lattice FPGA boards are back from fab and should ship this evening 😄
Then assembly either Friday or Saturday 🤓
Going to be a fun weekend
keen lichen
@wicked matrix one tip I have for soldering is raising the temp of your iron for the connectors and sometimes ground pins in general. The more copper and metal connected to the pad will wick away the heat much faster than an IC pin connected to a thin trace. I believe the solder will flow onto the whole pad when hot enough. (Fancy irons will do this automatically which is on my gear wish list.)
wicked matrix
those SMA connectors have a LOT of thermal mass.
also very easy to burn yourself if you're not careful (ask how I know)
vernal garden
Wait, auto-regulating irons? That puts my decade old Weller to shame....
wicked matrix
this is a thin board with GND covering most of both sides, so I was also caught out by just how hot the whole board became to handle, after working on those honking GND pins
wicked matrix
yeah I think that's what this is
bitter gale
You could go with a gas soldering iron too they heat up faster. Thats the route i went and i dont regret it. Of course with my project im under my house soldering so pulling a regular soldering iron with me could be hazardous to my skin
icy moth
When you need to test all the digital pins sequentially when you make your own Arduino board:
Just line up 14 LEDs with 330ohm resistors and you’re good
trail forge
I am trying to use a TPS2034p on a breadboard https://www.ti.com/lit/ds/symlink/tps2034.pdf
it's a 8 pin DIP.. my question is two of the pins are "IN" and three of the pins are "OUT" do they all have to be used? or can I just use one of the IN's and one of the OUTs?
and obviously the GND and EN pins
for it to work right do I need to tie the two IN's together and the three OUTs together?
pine igloo
Those pins are likely discussed in the context of the solder mask thingie.
They're electrically equivalent but are provided due to thermal constraints, current handling or the like .. that's my guess without doing any reading.
icy moth
This is one example given in the data sheet
It like many of the application examples the all output together
And the input are tied together as well
pine igloo
The little catalog suggests there may be two distinct circuits.
No, the part number given is a 'single' and matches the leftmost drawing SPST.
trail forge
I think @icy moth is right. They do show them tied together. I'll try that next
pine igloo
I haven't seen a thing suggesting you would not tie them together externally as well.
Was surprised the 'landing' pad diagram doesn't have them tied together.
trail forge
I'm not used to a single "switch" having multiple in's and OUT's
icy moth
Yeah, it’s interesting for sure
pine igloo
Got to be for thermal/current related handling.
icy moth
That’s what I was thinking @pine igloo
pine igloo
It shows separate pads, which isn't great for thermal.
icy moth
My guess is it does current divider over the three outputs so it can deliver max current in constant current mode
pine igloo
I don't remember the other example I looked at, months ago, with a similar issue to it. That one (unless I'm misremembering) had the pads connected, for better thermal dissipation.
icy moth
DIP has big leads so thermal dissipation shouldn’t be too terrible on it
I’d be more concerned on SMD variants
pine igloo
Figure 40.
So fig. 40 fairly well settles the argument of 'would it do any harm' (no) to bond them together.
icy moth
Overcurrent protection for hot plug applications
pine igloo
PDIP isn't going to have a land pattern. My bad. ;)
(gonna have holes to accept thru leads)
icy moth
I feel like I get so much better at reading data sheets when I’m trying to answer questions for people. Such a nice feeling
pine igloo
These little doo-dads can be used for USB.
https://www.ti.com/product/TPS2034
This is why a good laptop won't blow when you abuse the USB system. ;)
_ Application notes TPS202x/3x And TPS204x/5x USB Power Distribution_
@icy moth Yeah it's different when you're putting your name on an opinion about what's in a datasheet and what's not. ;)
escapes to the dinner bell
icy moth
Lol true
buoyant lintel
So uh... Is there any way to tell if I soldered it right, except for just seeing if it works?
desert cipher
resistance testing? dunno
buoyant lintel
There's definitely some solder vaguely in the vicinity of the pins. Good enough??
buoyant lintel
Oh... I think this breakout and this chip aren't actually the same footprint. Whoops.
That would explain why it didn't want to click into place
tropic drift
hello i have some questions and running out of options on what to do. I'm not even sure if I am in the correct place for asking these questions if that's the case let me know where I can. I just bout a circuit playground and cannot copy the lib folder to it. My computer keeps saying not enough space available. I tried using terminal with the commands listed on the website and nothing.
tropic drift
oh sorry mac os 10.15
tropic drift
2.1mb available and 1.7mb is the lib folder
desert cipher
you need more space as you need more for copy over to work usually
maybe try emptying trash
and usually theres gigbytes so you are really low in space.
tropic drift
deleted everything possible on the board and emptied the trash
what is the usual available space on these boards?
desert cipher
ahh board device not computer heh not sure though not sure what else can clean up though
try it again since trash is emptied
pine igloo
2 MB on Circuit Playground Express iirc.
Generally you can mkdir /lib on the circuit playground express. Then copy related files to it.
Copying the entire library collection is way overkill as most of it is never used.
(there might be room for all of it; I don't remember)
tropic drift
i was just trying as the online instructions said but i'll try with terminal
pine igloo
Circuit Playground ATMEGA32u4 based. Is that the one you have? Or the Express with ATSAMD21?
I didn't see any SPI flashROM on the Circuit Playground.
tropic drift
express
pine igloo
CPX has 2 MB storage on-board.
It's an SPI flashROM formatted as a filesystem.
You could be able to copy a small text file to it.
If that works, make a new directory on it called lib if it doesn't yet exist.
tropic drift
there is one currently on it. I'm kinda new to using terminal a lot so trying to piece together all of the commands to manually copy it that way will more than likely take me some time. So more than likely I will just be copying things as I need them.
pine igloo
You can cd /path/to/media first in the Terminal.app
It uses Unix pathnames (forward slash not backslash as path element separators)
tropic drift
let me try that
lol I'm not gonna lie kinda struggling with this. I won't keep you occupied on this. Thanks I appreciate it.
pine igloo
I'm around for a bit. ;)
tropic drift
i don't know if you might laugh at this but between three tabs on chrome on how to this. This is what I've been doing cp -r /lib /CIRCUITPY
it was there is no such file or directory
lol
pine igloo
I like to change directory to the target directory and 'pull' the file, not 'push' the file from the source directory. Simplifies everything quite a bit.
same command (cp) used for either case.
tropic drift
i went to directly to the the lib folder on terminal using cd
once here what would you suggest to type
tropic drift
so moving the lib folder to the cpx like that would not be possible there are more folders throughout the computer named lib? did i get that right?
plain dagger
/lib points to the lib folder at the "root" of MacOS. ./lib would be the lib folder at the current directory.
tropic drift
ohhhhh gotcha
plain dagger
@tropic drift also, in case you didn't see this before, MacOS likes to do its own thing with file indexing: https://learn.adafruit.com/welcome-to-circuitpython/troubleshooting#macos-loves-to-add-extra-files-2978466-45
tropic drift
@plain dagger i tried that too and followed all the commands listed there and still nothing.
twilit depot
I need help with linux persistence
tropic drift
I don't understand why it doesn't want to load the library folder on the cpx
I really don't what things I would use or not. My best guess was to follow along on the instructions.
plain dagger
@tropic drift ok. just making sure. 😄 also, the reported disk space is faked iirc. will it accept things one-by-one, as opposed to the whole folder?
tropic drift
if put one at a time yeah it adds them.
plain dagger
@twilit depot i'm not sure what you mean by "persistence", but go ahead and ask your question. someone may know.
tropic drift
but dropping the whole folder it won't
twilit depot
I wanna create a portable linux usb with debian 10 32 bit xfce so it works on most of the pcs
pine igloo
Dropping the whole folder may not fit by a small margin.
Figure out what you need from that folder, and copy just what's needed.
I'm sure there's a primer that outlines this approach.
tropic drift
i guess i'll have to go one at a time to add what I need. Thanks for the help.
pine igloo
Start with that and see if it works properly.
Plonking an entire ./lib onto it may in fact work (I don't know) but is rarely necessary.
trail forge
@icy moth and @pine igloo and @hearty karma : It works!!! The TPS2034P as a switch to turn off the sensors during deep sleep on the ep32
I'm down to 0.0020A from 0.042A
pine igloo
Cool, @trail forge -- that's a nice chip btw. I want one, now.
trail forge
🙂
@icy moth is making a breakout version for the TPS22917. It should be really sweet
night all
pine igloo
nice job.
mental mica
How unusual would it be to design a PCB that'd normally be protoboard?
Like, to have items like adafruit components (an arduino with headers, an electret microphone breakout with headers, etc), and design a pcb that they can all be soldered to?
To give some context, I've got a pretty complex project (arduino nano, 8 28-pin SOICs on breakouts, a buck AND a boost power supply, an electret mic) that optimally would be better on a purpose-built PCB with custom circtuitry, but I honestly don't have the requisite knowlege-- I don't even know how to design a boost power supply
But I do have the headered components all together on a breadboard, and it could be majorly compacted if I just had the same components on a pcb
I dunno, is it worth it?
peak spear
so a PCB where the "components" are mostly modules?
mental mica
Yeah
peak spear
it's not the worst idea in the world so long as absolute minimum board size isn't critical
another possibility would be perf board, but it's a lot of wires
mental mica
That's kinda what I was thinking-- this thing is gonna be a bar-graph music visualizer using 7 IV-21 (13mm x 72mm long) tubes, so I'll have decently large space to work with due to the sheer size of the tubes
peak spear
oh yeah, the IV-21's. How does it look so far?
peak spear
the pro mini is doing the FFT, nice!
mental mica
The code is sufficiently object-oriented, so, easy to mess with, and doing all the processing for 7 tubes results in 13ms between FFT updates! (the display gets refreshed 4 times during that period, 'cause I gotta keep the multiplexing going)
peak spear
I bow to your coding chops 🙂
mental mica
I'm still extremely new to c++, such that typedefs and C-stuff like memcpy() still scares me
but I've read enough to be comfy with classes :)
peak spear
it's an impressive frame rate for such a small MCU
mental mica
Yeah, that's due to some well-optimized code for the displays (a full 1-grid-per-tube update requires sending 20x7 bits over SPI, so multiply that by 8 for all 8 grids), but MOSTLY owed to the fft library
If I can even call it that-- it somehow functions despite literally being a .h file and some machine code in a .S file-- I didn't even know that's possible
mental mica
Thanks! I'm really excited to get it all nice & polished 🙂
peak spear
its a bar graph type display
bitter gale
Ohh for music thats right
mental mica
yup!
bitter gale
Got it mixed up with someone else’s project lol
peak spear
I love using MCU's to drive tubes, just seems cool
mental mica
Yeah, it allows for the nostalgic coolness of tubes, AND gives you some beefy performance to drive them in an easy way that wasn't possible back then
bitter gale
Tubes in themselves are cool. I really wish i could make my small solid state amp into a tube amp
peak spear
maybe you could design a PCB in a kind of hybrid mode, some modules, some of the easier modules placed as discreet parts
mental mica
Yeah, the chips for driving the displays can def be soldered direct-to-board
I bought them as a reel & slapped 'em on some breakouts
peak spear
you have one mini doing FFT and one as a driver?
mental mica
oh, lemme clarify
the arduino takes mic input, does fft, and generates the array of bargraph values
to drive the tubes, I have 1 high-voltage serial shift-register chip to multiplex each one (7 20-output shift register chips in total)
I just daisy-chain the shift-registers, and clock data into 'em from the 1 arduino
peak spear
oh, "with 2 of 'em" refers to the tubes
mental mica
oh, yeah sorry that was a lil unclear
but anyway, yeah, the shift registers don't need to be a module
peak spear
even better, when I started in electronics all there was was tubes lol, now $5 of silicon can do the job
mental mica
It's amazing how cheap stuff is
peak spear
my first 4K memory board was 8" x 6" and cost $100 in the 70's
peak spear
all TTL
before EEPROM
I forget how many chips, but a large array of 'em
are you going to put the finished product in a box of some sort, to protect the tubes?
mental mica
I'm not sure yet! I do know that I want a dark stained-wood base with brass accents & the tubes comin' out the top
if I use it as a shelf-decoration, I'm pretty confident that there's not much to worry about in terms of protecting the tubes
peak spear
you could sell those for big bucks, from that description it'll look great
mental mica
Unfortunately it's not too sustainable as a business model, as IV-21s, despite their cheapness, are in limited supply & not manufactured anymore
mental mica
Yeah... but the price :/
peak spear
I've seen folks quit their day jobs and sell Nixie clocks, in a nice case they go for thousands
mental mica
Dang, that's actually pretty surprising to hear
I didn't think there was that much demand
peak spear
we are not the only folks drawn to the nostalgic look of tubes. not a HUGE market but a market
and I've never seen what you are doing for sale
i have a bare bones Nixie at my desk, even non-technical folks stop to ask what it is
mental mica
Yeah, using 7-segment displays sideways as a bargraph is definitely a random idea
but like, it looks so cool that I have to make it work
peak spear
even as VFD, seven segment is sooo common it doesn't look as cool
mental mica
the neon-esque glow of nixies is just so... signature, I guess
VFDs come close, but the more flat nature of em isn't too great
peak spear
most folks have never seen a Nixie, or that lovely blue-green glow of VFD for that matter
(except as an odometer)
mental mica
Yeah, and that's where I feel particularly drawn to these specific tubes-- the fact that they're an actual tube gives them a lotta character imo
peak spear
exactly, else you could just use some neopixels and be done, but it wouldn't have nearly the character
you may also want to ask in #help-with-hw-design for thoughts from folks who have used a hybrid approach
Do you have KiCAD or Eagle or some PCB software?
mental mica
I've got a eagle license through my uni email
Tbh, my main concern is attaching the tubes to the pcb
I wanna have header-based mount so I can easily swap them, but that'll require designing some sorta 3d-printed base for the tubes, and I'm struggling to envision something that'd work well
peak spear
madbodger may have some thoughts on best practices for tube mounting
mental mica
Yeah, I'm hoping so
It's just a lil difficult since 19-pin tubes don't really have any sort of standard socket mount
peak spear
they only have wires right, not pins?
mental mica
Eeeup
which is why I'm thinking I'll have to design & make a "base" to attach to each one
peak spear
maybe a simple 3d printed disk is sufficient
they don't get hot, maybe something squishy between the disk and tube for shock absorption
mental mica
optimally, I'd like to have a solution as clean as farny's-- a base that converts each tube wire to a good, rigid pin
Probably not too doable on this small scale though :/
peak spear
yeah, whats the spacing between pins?
mental mica
8mm diameter, and what looks like 18° spacing between pins
peak spear
@native hare there are inexpensive Nixie power supplies out there, or whole PCBs for $50 - 100
@mental mica yes kinda tight to add rigid pins
mental mica
did the math, ~1.3mm arc length between pins
of course, that's straight out of the tube, and the wires can bend outwards as needed
peak spear
and 1mm pins aren't going to be that much more rugged
anyway, work tomorrow, the very best of luck and please keep us updated @mental mica it is a very cool project!
mental mica
Will do! 🙂
hasty knot
does anyone know if there's any soc other than rpi that fits for emulation? something that spits out rbg?
real scarab
People use FPGAs for emulation.
hasty knot
unknown territory
hehe
doesn't seem very flexible though
but of course, nothing is gonna be as flexible as software emulation, not really the point i assume
real scarab
With an FPGA you literally upload the game console's hardware into the chip.
real scarab
There's a bunch of YouTube videos about this, it's pretty cool. Because it's in hardware, the emulation is almost perfect.
hasty knot
are they solid state or volitile then?
real scarab
Not sure what you mean by that. An FPGA is a chip that you can reprogram indefinitely. But instead of using software, you work directly with digital logic gates.
hasty knot
probably applied those words on the wrong thing but yeah
do i have to reflash it or is it swappable on the fly, which it sounds like
real scarab
When you turn off the power, the FPGA forgets what it was programmed to do. When you apply power, it usually reads its configuration from Flash memory. So if you want to change what it does, you just upload a new configuration to the Flash.
hasty knot
okay alright, so they're volatile
in the sense i meant it
like ram
heh
i'll look into that, cheers.
can't perform well on anything 3d though can it?
or at all
real scarab
I think people use FPGAs to emulate Sega Dreamcast.
But there are obviously limits to how fast an FPGA is. 😄
hasty knot
Hehe
This project has turned out to be a metric ton of stuff to wrap my head around
Or, throw money at, but buying a rpi to emulate and then having to get a scart connector for more than the rpi cost feels sad
real scarab
Why do you need the SCART connector? Are you using a CRT?
mortal aspen
Is there a raspberry pi zero case that's not over $3
hasty knot
box it comes in?
mortal aspen
No the case it goes in
hasty knot
jk, yes. but you probably have to order it from banggood or alibaba if you want it that cheap
mortal aspen
Eh
mortal aspen
-_-well WHERE THE F am I gonna get a 3d printer
hasty knot
What
No need to get upset
and, no need to 3d print it. You realize things are made by hand of other materials?
mortal aspen
OH sorry I just like caps
hasty knot
take some other container or thing, mark for inputs, make holes
be careful and it might just look good
mortal aspen
Okey
hasty knot
or like, wood and glue.
or some random thin metal sheet, cut and bend?
use that thinking meat we got in our heads you know
might learn someting :P
hasty knot
build it out of lego
who knows
i bet you got some stuff that you can use.
i mean, this is an old can of tuna
hasty knot
if you aint got cash you gotta be smart ;)
mortal aspen
Lol
real scarab
The other day I built a logic probe into the tube that used to hold my solder. 😄
real scarab
hasty knot
Oh that looks nice
real scarab
I was wondering what to put it in, and it turns out this tube thing was an ideal fit. Never throw away things! 😄
hasty knot
NEVER
like, why wouldnt you keep 20 boxes of unopened mitel telephones from the 90s?
People keep saying it's odd but throwing them away is odd if anything!
Hehe
Made a crt discharge stick yesterday
Does not look as good.
Plus I need the screw driver 😄
real scarab
Better than using your fingers.
trail forge
@pine igloo, @icy moth and @hearty karma : Adding that Ti TPS2034P switch to cut power to my sensors during my ESP32's deep sleep took my 24 hour power usage from 297mA down to 170mA a 43% reduction.I should be able to run over 12 days on an 18650 (2200mAh) Lipo
icy moth
Very nice!
trail forge
Thanks for the help gang
pine igloo
Sippin'.
icy moth
Straight sippin’
trail forge
it runs for 30 seconds takes it's readings.. and goes to sleep for 5 minutes
and during that 30 seconds it connects to adafruit.io and logs it's readings thru my wifi
pine igloo
Heh that's a fast login.
trail forge
ya That's one of the reasons I picked the ESP32.. it can do wifi fast
pine igloo
Oberon running on an old IBM laptop, at a time before Linux was easy to place into sleep mode .. was a fast boot.
pine igloo
Put the laptop on the counter in the c0ffee shop. 30 seconds later, typing that thing that occurred to them on the walk over.
trail forge
now I just need to rewire it on a proto board.. or something and put it outside with a soloar panel and charge circuit
pine igloo
I wonder if Dave is making any more of his tombstone boards for the CPX.
It stood on end.
@raven latch etsy
trail forge
tieing the inputs together and outputs together made that switch work just fine.
I think I actually should be ok using adafruit's 6v 1w solar panel
but I really want to go nuts and use the 6V 2W one.. but I would have to modify the stl to make it fit.
hmmmm
I'd like to add a battery monitor to this setup.. That would eat some power.. but I saw a way to use voltage dividers and a transistor to tun the divider on and off to save power.. but so far that discussion was over my head
pine igloo
If you cook it ..
trail forge
then dinner is done? 🙂
I married a math major.. should have asked her to take EE as a minor 😄
pine igloo
Just say 'Sparky' a lot.
pine igloo
I can't even tell my stories. ;)
trail forge
🙂
pine igloo
I'm on a handheld. ;)
Fought Kindle + Calibre battles today, to be able to read James Joyce.
One of the things I like to think about .. is how to raise the floor of an analog Ammeter.
(or Voltmeter).
So a generic milliammeter (probably 50 uA movement come to think of it) .. that reads 18-22 volts, or 2 to 5 Amps.
How to spread out the reading you want over the entire range of the meter.
Most solutions for panel meters put you near the top of the movement in your target range.
I think I wanted it so that was still true, but to be able to glance at the meter from several feet away, when it was on the lower end, and have it still read a significant portion of the upper range's value.
To differentiate between 11.7 volts DC and 13.8 volts DC, for example.
thick prawn
I have a new Alienware laptop that only came with 106 gigs of space
But I have some external SSDs that I can use
How do I get my hands on a Windows 10 ISO, and boot from the external drive
Wait, I'm not sure how these things work, uhhhhh
Do I install windows on the internal smaller drive, and simply use the SSD outside for general storage, or do I boot from the drive, and install windows on the drive?
frank jay
The video linked in this Prusa Prints post is Private
https://www.prusaprinters.org/prints/39421-neopixel-led-torch
I'm not sure how to correctly route that information, whether it's a github issue, comment on the post, discord channel or twitter...
bitter gale
@thick prawn use the ssd for the boot drive they are so much faster than a hdd
bitter gale
You might have the space to make it internal
And you can usually take apart the external case and its just a regular ssd inside
With a sata cable n such
stuck halo
Can anyone help me use an aurdino to show altitude and air speed in Microsoft flight simulator with a screen attached to it
icy moth
I really love that Texas Instruments has its TPS6223x buck converter designed such that you can use chip inductors and take up such a tiny space on the board.
Also it can use ceramic caps (X5R or x7R rated) too which helps save space
vernal garden
@mortal aspen
This is being sent in a public channel due to your DMs being disabled.
I'm one of the Community Moderators on the Adafruit Discord.
Your earlier comment (https://discordapp.com/channels/327254708534116352/327254708534116352/747784249180028959) is unnecessarily loud (in all caps) and indirectly references a swear word. Such behavior & language is prohibited by our Code of Conduct.
Earlier, another moderator communicated to you regarding another issue. When they attempted a subsequent message, DMs were blocked.
Please note that the next violation, regardless of severity, will result in a ban. Review our #code-of-conduct before posting again.
covert hound
Does anyone have a preferred app/method for mirroring an android (6.0) phone to a desktop (win10)? I am aiming to screen capture demos.
cyan hemlock
@covert hound some devices can record screen via ADB. There is a button inside Android Studio logcat window for it.
ADB a command line Android Debugging tool that allows the PC to control an Android device, mostly used for development. If you prefer not to set up all of Android Studio you should be able to get ADB by itself and use a command with it to record the screen as long as your device supports it.
buoyant lintel
Welp, since my wson breakouts apparently weren't the right size, I decided to mill one myself, and throw in pads for the decoupling caps while I was at it. Good times
covert hound
@cyan hemlock Thanks! I will check it out
vapid wedge
What's a good resource for electrical engineering quizes?
primal tiger
I want to start learning electronics from scratch
how do I do this?
I went through r/AskElectronics wiki/faq for beginners
I still don’t have a clear idea how/where I should begin
Where does adafruit or sparkfun or arduino fit into this, and is there a learning track for this
I’m so confused
I also want to emulate this in Minecraft
I’d communicated with some people on reddit/discord and it seems like I can apply knowledge of electronics to minecraft, albeit not 1-to-1, and anything I learn I can translate into real life projects very easily
but I don’t know where to start, can someone please help
Computation Structures - Part 1: Digital Circuits | edX
https://www.edx.org/course/computation-structures-part-1-digital-mitx-6-004-1x-0
This course has a prerequisite course mentioned too
Is this a good place to start?
real scarab
@primal tiger I'm not sure exactly what you're interested in. Are you talking about emulating a digital computer circuit in Minecraft? In that case, I would recommend the book CODE by Charles Petzold. It explains the basics of computers and digital logic. The book is from 1999 and it explains techniques from the early 1980s but those are still the basics for computers today. Or are you asking about learning electronics in order to build your own things in real life? In that case I recommend the book Make: Electronics by Charles Platt as a good starter.
hearty karma
Another good resource if you want to get started in electronics is the electronics learning kits offered to children (like Lectron and Snap Circuits). They have lots of basic circuits to build, along with good explanations of how the different components work together to accomplish various things.
pine igloo
I got a Radio Shack 50-in-1 kit in 1969 which started my interest in electronics. The day before, I must have had a different career path in mind. Probably biology ('nature').
clear quarry
in this tutorial -> https://howchoo.com/g/ote2mjkzzta/control-raspberry-pi-fan-temperature-python
he uses a NPN transistor (2N2222) i have a NPN transistor (2222) is that the same?
primal tiger
@primal tiger I'm not sure exactly what you're interested in. Are you talking about emulating a digital computer circuit in Minecraft? In that case, I would recommend the book CODE by Charles Petzold. It explains the basics of computers and digital logic. The book is from 1999 and it explains techniques from the early 1980s but those are still the basics for computers today. Or are you asking about learning electronics in order to build your own things in real life? In that case I recommend the book Make: Electronics by Charles Platt as a good starter.
@real scarab Can I do both
I don’t have a really, really specific area of interest, but right now I think I’ll focus on the former
thanks for the answer!
pine igloo
@clear quarry Very likely the same. Any common NPN will work.
clear quarry
@pine igloo ty for thar
bleak ospreyBOT
Adafruit is now live! join us on https://youtube.com/adafruit/live
pine igloo
@clear quarry Most small simple projects can use any BJT you have handy, just make sure you use the same kind (NPN, or PNP).
bleak ospreyBOT
Adafruit is now live! join us on https://youtube.com/adafruit/live
buoyant lintel
@primal tiger my general strategy for getting into a new skill is to pick a project that needs the skill, and use that project to point me in the direction of what I need to learn
pine igloo
I treated a dictionary as an index into the language, using the definition of one word to learn other, related words. In that manner, built a vocabulary.
I use a similar approach with electronics, but the sources aren't a 'dictionary'.
Reading schematics, and datasheets, helps.
They say mathematics is a 'language' .. so are schematic diagrams.
bitter gale
@primal tiger i second what sheltatha said there. Ive found jumping into a project starts me on the path to finding other things i can make and spurs learning more to accomplish whats needed. It also sinks in better if you have something to apply it to cuz if you just read this or that but dont apply what your learning to something then your not gonna get far and also tire if reading about it
primal tiger
thanks for the advice!
right now, getting components is tough, so I was looking around and found that I can apply what I learn to minecraft in some capacity
hearty karma
That's a new one on me. I don't recognize the connector nor the symbol.
clear quarry
maybe a stupid question
adafruit uber guide
Place a 300 to 500 Ohm resistor between the Arduino data output pin and the input to the first NeoPixel. The resistor should be at the end of the wire closest to the NeoPixel(s), not the microcontroller. Some products already incorporate this resistor…if you’re not sure, add one…there’s no harm in doubling up!
this also apply to my 16x16 right!
hearty karma
If it has a first neopixel, yes
icy moth
@hearty karma question for you
If a LDO has an output range from 1.2V-5V, and a supply pin on a device is supposed to draw 1.2V, I’m measuring 3.3V across the caps on the 1.2V input. It’s on a separate regulator from the 2.5V pin and the VCCIO pins
I’m supplying 3.3V to the board with 3 separate LDO for each voltage range.
Maybe I should just have used those small footprint buck
I’m guessing I should hit the drawing board again on this one
I found this part with the Digi-Key mobile app. https://www.digikey.com/product-detail/en/TPS73201QDBVRQ1/296-19676-2-ND/1033596 this would drop right in to what I have
Pin out is the same
Or maybe @pine igloo do you have any suggestions?
I’d rather not reorder boards if I don’t need to
pine igloo
What are you trying to do?
icy moth
Drop 3.3v to 1.2V and also have 2.5V
pine igloo
heh.
icy moth
I know I need 2 different regulators/buck setup
clear quarry
erh i have a "stuck" pixel on my matrix :/ it's not there when i start up the matrix and the ESP32
pine igloo
I don't really understand what 'buck' means the way people toss that term around. It used to mean a transformer winding out of phase with normal.
icy moth
Buck/step down
pine igloo
Bucking literally means bucking. boost/buck as a pair in terms.
I don't know how the solid state version works, if it exists.
Could be an oscillator in there somewhere.
(use DC to create an oscillator; which is AC; rectify the AC after step up/down with a transformer)
The LDO means literally low drop-out.
I'm having trouble making sense today. ;)
In general, you don't cascade LDO's if you can help it.
(I think plenty of people do just that, but I sure don't)
There are wide-range input voltages on some kinds of supply modules.
So I would set the rail to the highest DC voltage the project needs.
Just like with an ATX supply you may see multiple rails at different common values, such as 12.0, 5.0 and 3.3 volts.
icy moth
it's a feather wing so 3.3V is regulated on the associated feather. It also used VUSB because the RGB LED needs a certain input voltage to the open drain inputs on the lattice IC. Then I need 1.2V for VCC & VCCPLL, 2.5V for VPP2.5, and 3.3V for VCCIO
pine igloo
That's a lot of mojo. ;)
icy moth
it's. a lot going on for a simple feather wing
pine igloo
Well in theory you read the datasheets and cruise around stackexchange looking for answers.
Sombody's either done that or can say why you mustn't do that. ;)
proper escarp
why not just put one fixed voltage LDO providing 1.2V, another providing 2.5V, both from VUSB?
pine igloo
shurik: that works fine if the LDO of both regulators has the same 5 VDC input.
proper escarp
and use 3.3v pin of feather for 3.3v
icy moth
That's an option. I'm going to use the 2.5V and 1.2V drop in equivalents on the current design and then switch it up for the next iteration where those LDO are off VUSB
pine igloo
If I want to hack my kindle paperwhite 3 I have to work with like 1.8 volt signals.
icy moth
1.2V says caps on input/output V is optional. for the 2.5V, I'll just need to change the 0.47uF on vout to 1uF and it will be good
not ideal to cascade but I don't want to order new boards right out the gate.
pine igloo
I just assume there's an LDO on the other side of the USB jack, inside the computer, so technically we're already in cascade. ;)
icy moth
very good point lol
pine igloo
But .. they made it commercially and knew it would be treated roughly.
So maybe it's an LDO (or regulator) based circuit, but with differences.
It's easy to just assume I have this part in my hand and it plays a role and I think I know what that role is, when I don't. ;)
icy moth
Good notes for the next iteration
pine igloo
IN the old days, you had a transformer secondary winding. That was your effective starting point. A bit earlier than that, there was this 'hot chassis' idea (and danger).
One of the things they did was to provide multiple secondary windings on a single transformer core.
switching power supplies remind me a bit of hot chassis, which is why I don't trust them and don't fool with them too much.
They save a lot of shipping weight, which is how we ended up with so many switching supplies in our lives. ;)
hearty karma
You say you're using a regulator with 1.2V - 5V output, so I'm guessing it's adjustable, presumably via the feedback network. Have you checked the resistor values to see if they're the proper ones for 1.2V? Alternatively, some regulators come in specific versions with fixed voltages, if so you'll need a different part for 1.2V.
icy moth
You say you're using a regulator with 1.2V - 5V output, so I'm guessing it's adjustable, presumably via the feedback network. Have you checked the resistor values to see if they're the proper ones for 1.2V? Alternatively, some regulators come in specific versions with fixed voltages, if so you'll need a different part for 1.2V.
@hearty karma I found drop in replacements for 1.2V and 2.5V
hearty karma
And the 1.2V part isn't delivering 1.2V?
icy moth
well, it was a 3.3V regulator that had a range for 1.2V-5V out. But i'm guessing without a voltage divider on the output, it was going to always do 3.3V. A misunderstanding of how that specific regulator functioned.
hearty karma
That could be.
If so, you might be able to tack on a couple of feedback resistors to set the desired output voltage.
icy moth
It's a different beast getting into variable supply systems where you need 3+ different voltages. So it's a slight learning curve
hearty karma
You've already figured out the bulk of it, and know you want a separate regulator for each different voltage. Now you're down to implementation details.
icy moth
Yeah, I'm hoping these drop ins fix the issue because that will be a huge time saver. Then the next iteration can be more refined.
At this point, I'm just thankful TI has drop in alternatives
pine igloo
_11
It is not only right to connect a 3.3V regulator to the output of a 5V one, it is considered normal. You find that arrangement all over the place. The main advantage is that the 3.3V regulator doesn't need to drop as much voltage, so can be smaller as it dissipates less power.
The main caveat though is that the 5V regulator has to consequently handle more current, as it has to cope with all the 5V demands and the 3.3V demands, so you should take that into account when choosing the 5V regulator._
icy moth
Yeah, I’ve known about that consideration
So it should be okay
Just don’t expect to run high power systems off the GPIO lol
pine igloo
This bothers me a lot:
Are there any timing issues related to startup/shutdown? When power is first applied does one rail need to be stable before the other turns on, or vice versa at power-down? – Matt B. Jan 3 '14 at 21:20
from
https://electronics.stackexchange.com/questions/95342/5v-and-3-3v-power-supply?noredirect=1&lq=1
My first approximation was the 'master power switch' that you throw, that brings everything up 'at the very same instant'. ;)
I'm pretty sure now (not certain) that I've seen schematics I trust that cascade 3-wire regulators.
icy moth
Well, the 1.2V and 2.5V will be in parallel so only 2 regulators in series at least on the Vusb to 3.3v to 1.2/2.5V
pine igloo
Right. Just assuming 3 cascaded is 'worse' than two cascaded.
pine igloo
Most of the stackexchange talk is about efficiency, which of the multiple regulator packages needs a heat sink; and .. battery life effects on this design approach.
icy moth
Guess we will see what happens when I bring it up 😬
pine igloo
Somebody said cell phones use 'DC to DC converters' because 'they need to achieve so many different voltages in them' foo.
You're using your brain, so you're going to be fine. Or, at least, eventually. ;)
icy moth
haha very true. It gives me something to talk about when I do my 2nd round interview with Texas Instruments in the next week or so
pine igloo
That sounds like fun!
Connect with the interviewer. Don't be afraid to be human, because if you cannot be, how good was that job, again?
Of course I used to smirk too much.
icy moth
haha, I find myself to do okay in interviews. Even if I think i came across a little brash
I'm also interviewing with L3Harris for an embedded software engineering role. I got a little snippy when asked why my GPA (a 3.25) was low
pine igloo
brash is better than a lot of other things, but you can catch them on a bad day and they'll just drop your application in the wastebasket before the door has closed as you exited their office.
icy moth
I got a second round interview request so I guess it wasn't too bad lol
pine igloo
Friend of mine said he applied to some wierd place and they put him in a cold room.
pine igloo
I'm gonna get out of here. Nice to chat with you.
icy moth
have a good one
pine igloo
🛩️
chrome citrus
Good evening gentlemen. I hope everyone is in good health and keeping safe.
I just finished coding for the adafruit amg8833 thermal imaging camera and I'm very happy with everything. I just tried to add a blinking LED to the code and the time.sleep(0.25) to make the led blink seems to interfere with the whole function as the counter slows down significantly after the led blink command is triggered.
Is it possible to blink the led without using a time.sleep delay? Everything works perfectly without using a timer here.
icy moth
yeah, you can use a for loop and if statements
chrome citrus
Thank you skerr I'll give that a go.
loud brook
hello, any engineers in the server?
icy moth
There are a lot on this server
loud brook
i have this real easy assignment for school and dont know any engineers to ask but other than here. these are the question that they want me to ask.
bitter gale
So now i am wondering is 30 feet of cat5 cable too much for the arduino pullup pins to be able to handle? If so how would i tackle the issue to make it not an issue anymore?
bitter gale
I was thinking of reversing the logic and going with a 5v common through my limit switches and then back to the individual pins
But still 30’ of wire that turns into 60’ round trip
Not sure the arduino will push that much amps to make that
bitter gale
Im more wondering if its an arduino amperage limitation yhan the capacity of the wire itself
Could also be that i got a bad end
As i have it now i have 4 pull up pins that im watching to go low
When i plug in my cat5 the stepper drivers start skipping badly and the motors dont turn
So just a guess that the wire is pulling too much itself and causing it to go low
oak cove
The amount of current that passes would be the resistance of the internal pullup + the wire right? You would have less current, you would have an opposite problem if anything
waxen bear
I would think that trying to do comms through a long cable, without special hardware is going to create problems, through reflections or ground loops or something
oak cove
There are bigger things to worry about with long wires
bitter gale
I mean the plan is to ground them when the limit switches activate
oak cove
Sure, and the wire if its super thin, will act like a resistor, less current.
bitter gale
So do yall think reversing the system and going 5v and watching for a high on the pins might work?
oak cove
I am a fan of active low but thats just me and i dont think is in the scope of issues rn
waxen bear
I'm wondering if the reference voltages at both ends of the long cable are going to be the same,
what is low or high? You need a common ground / reference, and in a long cable that's going to be tricky
assuming you supply power at both ends
bitter gale
This was mostly just a loop
oak cove
Its for limit switches, so probably not
bitter gale
The way i had it planned anyhow
waxen bear
Right, so one side is completely passive, that's maybe better
bitter gale
I kinda wish i still had a 50’ cat5 laying around that was professionally made
At least that could tule out my cable end being the issue
oak cove
You can use a CAN bus 😂
icy moth
Yes, he... can
oak cove
Running a network stack just for limit switches seems odd to me
bitter gale
I could direct wire it too lol
oak cove
You could, and it will probably be fine
bitter gale
Issue is for what i am doing i need to to be swappable
oak cove
Connectors?
bitter gale
But that would give me a solid answer if the footage of the wire is causing enough draw to cause the pin to read low
icy moth
I’m pumped for show and tell though I know it’s probably going to be tough to get on lol
oak cove
Wait are you the fellow wiring up a house?
oak cove
Lol, great. You should figure out a common bus for the entire place for data so you can just keep adding on with minimal work
bitter gale
I mean i have a setup so i dont have to create another driver box if i can make the cat5 connectors work lol
oak cove
Have a central controller, maybe a pi or two for hosting control applications, lol, ethernet would allow for normal computers to wire in too
icy moth
Any chance you’d be willing to use DAC?
Higher power
Might be a smidge more expensive
bitter gale
Im hoping not to push higher power for this particular application since this is my first endeavor with a microcontroller
oak cove
Add a lora gateway so you can add wireless devices around your RV whereever you go 😆 I like this project you could expand infinitely
bitter gale
Lol nono i can only expand 4 feet off either side i dont want bigger slides
oak cove
Well say you keep leaving something at a site, put a LoRa tag on it, dont charge it for 10 years, and if you leave it behind you could get a phone notification
bitter gale
Its more of a singlewide than an rv. I dont want to haul the 18000 pounds from site to site
Just from here to whatever property i buy in the future
oak cove
Im just sayin, many ways to expand, like add solar
bitter gale
I had plans for a solar style air conditioning system
But thats more of a heat based thing
bitter gale
Im doing a mini split already
Gonna go double head unit
The solar ac is more of an experiment
Not using solar panels tho
oak cove
Nice, sounds like a neat project. Are the limit switches on the other end of the structure?
bitter gale
Kinda they are about 3/4 of the way down from the box on the slide tubes
I have 4 tubes 8 switches
4 are for going out and 4 for in
knotty raven
First time deciding NOAA satellite
bitter gale
My place is 50’ long
oak cove
Hm, with the Cat5e you wanted to run ethernet right?
bitter gale
On the flip side the 2 smaller slides are only 10’ away from the box
I just wanted to use it for the connections since i have a need to connect 8 pins i fogured itd be a clean way to accomplish that
So @oak cove do ya think the length of the cable is whats pulling those pins down?
karmic obsidian
WE ARE LIVE! SHOW AND TELL! https://youtu.be/xEWfCK2DmU0
bitter gale
I could see it being that the arduino might not have enough to power 4 pins at 5v
oak cove
Honestly, Im not too sure, dont quote me, but I think due to the strength of the internal pull up if it is wired correctly
Which arduino are you using?
bitter gale
Uno
oak cove
Which input are you using? Not 13 right?
bitter gale
Nope not 13
oak cove
Okay, and you're using INPUT_PULLUP?
bitter gale
I have 5 analogs and 3 digital using input pullup
oak cove
I didnt think the UNOs analogs had the pull up but I might be totally wrong on that
bitter gale
It worked in my testing
oak cove
If you short the switch, what voltage is measured on the input of the UNO?
oak cove
Well I actually meant open sorry
bitter gale
Let me go check. I dont have internet that far away so ill be back in a minute
oak cove
Oh wait a minute, the internal pullup is right next to the input and the switch isnt allowing current to flow, so if you have an issue detecting open switches thats not the issue
bitter gale
4.8 volts
oak cove
And the voltage on the 5V pin? 4.8v?
bitter gale
Didn’t check that one lol
But
I did notice the stepper started skipping when i put the multimeter on that pin
I have a feeling thats the issue is the length of wire is pulling voltage away
oak cove
If there is no loop of wire, current goes no where
Voltage is a potential, it doesnt really get pulled away
bitter gale
Well there isnt a loop when I attach the cat5 either since its open on the other end and not connected
Now im wondering if its the cat5 end
bitter gale
Yeah ive heard of long lines taking a small amount of voltage before tho. But it coukd be some tall tale
Only other thing thats odd is all the pins in the cat5 are pullup pins so even if they are creating a loop they shouldn’t cause issues untill grounded
bitter gale
Thats the whole reason i was wondering if the length was the issue. I have 8 pullups for that and 2 for other switches
oak cove
Oh.....
If Im not mistaken you made a 2.5 ohm resistor, might want to recheck the arduinos
Im not sure if that can cause an issue or not, maybe not
trail forge
argh I get so flustered by out of stock/backorder... and since one item is a lipo shipping is higher.. doh
bitter gale
Hmm i dunno do ya think running a 5 volt common line and looping it back to the pins and checking for high on them would be a better system?
oak cove
Yeah ive heard of long lines taking a small amount of voltage before tho. But it coukd be some tall tale
it does but because of resistance when you have a lot of current
@trail forge I feel that
Thats the whole reason i was wondering if the length was the issue. I have 8 pullups for that and 2 for other switches
I think I misread this, dont worry about the 2.5 ohm thing I was worried about
bitter gale
But in all seriousness would the 5v common make more sense or would be divide the voltage when all 4 switches are active
oak cove
I think the only benifit to that is you need to add an external pull down maybe
oak cove
Well resistors outside the arduino from the logic lines to ground
trail forge
digikey is out of one thing, adafruit out of another item.. so neither is the solution at the moment
bitter gale
So for my current setup or the 5v loop back one?
Been kinda bouncing back n forth a bit iot just wanna make sure i got it straight
oak cove
With 5V on your switches
oak cove
Im still confused why your current setup doesnt work though
bitter gale
Maybe mzero might have an idea?
oak cove
Maybe, by all my math this should work, but you have an issue with the switches open right?
bitter gale
I feel like in theory my current setup is probably the best so i dont have to worry about shorting the board is a wire gets mangled at some point
I mean they are open as far as im aware. Unless i have a bunch of broken grounded wires
oak cove
If they are open and you have pull ups the ground does not matter
Do they work sporadically, or not at all? So this is when the button is depressed
bitter gale
Yeah it will only tell the board its low when the pin is read
My switches aren’t connected yet lol they are reed switches
oak cove
Do they work sporadically, or not at all?
bitter gale
And its on n off sporadically yes
oak cove
Ah, so it might be either debounce or noise
bitter gale
When the cat5 is connected only tho
oak cove
I think your Cat5 is wired insecurely
I think its the wiring, not the length, if not than the reed switch is doing something weird
bitter gale
Reed switches aren’t connected yet lol
It’s literally a bunch of cat5 hangin in the air
oak cove
Oh, well I assumed we were working with a switch so I knew it worked properly with good connections
Check the PHY mate
bitter gale
Phy?
oak cove
I would wait for switches, and physical, your physical layer so I just mean the connections, you dont really have a stack it was kinda a joke
All my networking issues recently have been PHY related
bitter gale
Lol i didnt even know that term at all
The whole reason im stumped here is due to the open ended connections causing issues lol
oak cove
I think its the cat5 dangling thats the issue
bitter gale
I can take n short everything on the female cat5 and nothing changes. When i plug in the male end of the cat5 it starts freaking out
Ok so wire it up n see if thkngs change then?
oak cove
Yes
bitter gale
Alright i will see what happens
Its not hard from that point to change it to a 5v system and reverse logic anyways
Yeah its the length of wire pulling voltage lol i connected the wire to run to the switch and just for kicks turned it o and no more chatter at all which means it pulled it low
Gonna have to reverse my logic
@oak cove what size resistor do ya think would be good?
oak cove
10K is the usual value
bitter gale
Ok hopefully that will do it thanks for the help
bleak ospreyBOT
Adafruit is now live! join us on https://youtube.com/adafruit/live
karmic obsidian
WE ARE LIVE! ASK AN ENGINEER! https://youtu.be/hFgVxN0H-yc
desert cipher
paid vacation for voting for adafruit employees? im so jelious.
peak spear
I thought my 2 hours was good...
thick prawn
Is there a way to make a sort of FTP server in my local network
oak cove
Yes
ashen kestrel
anybody here go to mit?
thorny skiff
I knew a guy named Mitt, once.
oak cove
But either way yes @thick prawn
ashen kestrel
lol not exactly what i meant
upper coyote
@ashen kestrel I went to MIT a while before @humble jetty did. Why do you want to know?
ashen kestrel
im a rising senior, and I am applying to mit after deciding that i would rather get rejected than not know if i got in or not. i know that i can handle the coursework but do u have any advice to get in and make my application unique?
upper coyote
Any advice from me would be O.B.E. I applied in 1973, and have no idea how I got in...
buoyant lintel
same here - I graduated about a decade ago
I wrote my essay about chickens, if that helps...
(no, really. long story)
ashen kestrel
what do u guys do now? like if i got into mit what could i get out of it?
buoyant lintel
you get a lot of suffering, a piece of paper that proclaims that you can handle stress, and a network
icy moth
I feel like mostly people benefit most from the prestige of the MIT name and the network
upper coyote
I was a student from 1973-1982 and later came back as staff from 1987-1992.
buoyant lintel
skerr: yeah
icy moth
But what you get educationally you can get cheaper elsewhere
buoyant lintel
there's nothing magical about the teaching at MIT; they select smrat people, put them under incredible pressure, and the ones who graduate are the ones who can cope. did we learn more or better? unclear
icy moth
I see most prestigious schools only really having a bigger leg up when it comes to graduate school
Mostly due to larger endowments for research
upper coyote
The joke going around at the time I was a student was that it didn't matter what your degree was in, you'd end up working with computers (programming or building),
icy moth
Eh
Graduate school in most (not all) cases require you to pass the GRE and have a solid 3.0+
upper coyote
The most educational stuff I got from MIT I got from non-classroom experiences.
icy moth
And lots of good academic and professional references
I can personally tell you that you only learn so much in the classroom. All they are there to do is teach you how to learn. What’s really matters is what you do outside the classroom like @upper coyote mentioned
I’ve learned more from wasting money on PCBs that straight sucked and digging through data sheets for hours than I have in the classroom. And it’s not because of bad professors, it’s just class is for theory, life is for application.
ashen kestrel
do the interships and stuff at mit differ from any other college, im applying to mit, cmu, rpi, wpi, and rit
icy moth
They have recruiting channels specifically set up for those schools so you have that
upper coyote
That looks like a good selection.
icy moth
Apple, NVidia, etc.. have job postings specifically for those schools
hearty karma
Some of the most valuable stuff I learned was hands-on debugging and fixing stuff, and from a kids' electronic kit that let me get an intuitive feel for how the components actually worked.
ashen kestrel
thats really interesting, ig i hadnt really thought about where i was getting my advice from, for example, i really only talked to my school counselor and my friends about college and career stuff. idk why i hadnt messaged you guys sooner
icy moth
I’d personally go to a state school (which I am) focus on maintaining a decent GPA because it still matters even if it isn’t really relevant, and develop projects on the side
ashen kestrel
im still gonna apply to mit just so that im not left wondering if i was good enough or not, but if i dont get in then o well ig i have to get a normal education now lol
icy moth
I go to the largest Historically black university in the US, and because of the projects I do and have to show for, I’m out swinging with students from top colleges
proper escarp
@ashen kestrel they all are looking for something that sets you apart form tons of other candidates with near-perfect SAT scores and good letters from school teachers
icy moth
Heck, I’m even good enough to get an $85K return offer along side people who go to Rutgers and Georgia Tech and Stanford
proper escarp
but this is a lottery. I have worked with quite a few high schol students. some got to MIT, others didn't - and there is no logic apparent to me
icy moth
but this is a lottery. I have worked with quite a few high schol students. some got to MIT, others didn't - and there is no logic apparent to me
@proper escarp this is also very true
ashen kestrel
ive always wanted to work on robots. specifically ones related to mobility
proper escarp
one year in my robotics team the season was almost ruined because one girl got to MIT, and the cheif programmer - who by universal opinion ws stronger than her - didn't
icy moth
It’s worth saving the money to go to a top public university than going Ivy League or any other “top tech school”
ashen kestrel
like prostetic limbs, rovers, self driving cars, that stuff
proper escarp
@ashen kestrel what state are you in?
ashen kestrel
nj
icy moth
You can do that anywhere
Heck, I’m going to be doing a paid research project at my school to inject faults into autonomous vehicle systems
proper escarp
Rutgers is pretty good - sure, not as good as MIT or CMU - but it would be a pretty good place
ashen kestrel
u mean like put it into situations that the vehicle doesnt know how to handle, or like fix the code that doesnt work?
icy moth
Granted... I’m taking a graduate course which is one of the prerequisites for being asked to join
Yeah, basically trying to make the system fail and see what caused it to fail
proper escarp
@icy moth nice! i'd like a project like that
icy moth
It’s digital systems verification
ashen kestrel
👀 thats sick
icy moth
And even cooler is our work will be published 😃
ashen kestrel
where
proper escarp
@ashen kestrel I expect you have also looked at other good public schools in engineering - Georgia Tech, Virginia Tech?
icy moth
NCState
proper escarp
yes
our school - Stony Brook - is also quite decent, at least in computer science and math/physics; not sure about robotics
ashen kestrel
yeah i did but they are kinda far, im applying to njit
ashen kestrel
also i got a question about studying robotics, a ton of schools dont actually have a robotics major, and even tho im not 100% decided that i want to work on robots and stuff as a career, what do i study if robotics isnt available, electrical, computer science, computer engineering, etc?
ashen kestrel
ik but should i study it if i want to do robot stuff
icy moth
And if the EE, they likely have CompE
Computer Engineering (not to be confused with computer science) is big for working in robotics because of how much it focuses on embedded systems design
And embedded systems is the heart of robotics so 😬
You get a healthy dose of electrical theory, electronics, computer science, and computer architecture and digital design.
ashen kestrel
tru tru
icy moth
Alternatively, look at places like UNC Asheville and their mechatronics degree
It’s pretty well known in the region as being a great program
ashen kestrel
so now, in terms of getting in 👀 what shouldnt i do?
icy moth
Have a horrible trend of socially unacceptable tweets or social media posts
That’s a big one these days
icy moth
You should definitely gather the most influential letters of recommendation you can
icy moth
School principle, if you know any state senators or local politicians
Big names go a long way lol
proper escarp
competitions - from AMC to FRC - certianly help, and so does SIemens competitions