halcyon river
Building a CD player based on a old CD drive, project split in multiple tasks (not everything is in order):
o Implementation of the ESP32-S3-MINI ESP32-WROOM-32E > WIP
o PD (Power Delivery) triggering
o I²C to IDE I/O expander
o RTC circuit (Real Time Clock)
o Overvoltage and undervoltage protection
o Bluetooth implementation
o Physical control interface (screen, buttons, etc.)
o Data storage (EEPROM)
o FM Radio
o Data interface (SD card, USB port)
o DAC and ADC
dang I can't even pin messages
picking up from where I was, routing D+ and D- to my ESP32, I managed to get a .0053mm length diff between the two
halcyon river
Feedback on this routing? Amazing how a good layout can change routing
late cobalt
Feedback on this routing? Amazing how a good layout can change routing
two layer board?
late cobalt
4 ground planes?
halcyon river
My old layout required 3 signal layers
new layout only requires two but JLCPCB has a nice 6L deal with free epoxy filled and capped vias, vias in pad and 2U" ENIG
So I just have ground to fill unused layers
red crow
I'd put a power plane in there: top→SGGPGS←bottom
This track is really thin for 3V3
Should JP1 be after C1/C3?
If you're planning to provide power through J4 then this is weird
late cobalt
can you attach a schematic?
also I'd just throw the concept of stitching vias in the room
late cobalt
This track is really thin for 3V3
I mean.. depends on current
halcyon river
1A max
halcyon river
can you attach a schematic?
also I'd just throw the concept of stitching vias i...
For via stiching I've alreadt quickly read about it, not sure if there is a function in KiCAD to do it for me
Found a plugin to stich for me, however I'd like to know more about the benefits of stiching
halcyon river
This track is really thin for 3V3
13 mil, 11 mil would be enough
red crow
There is no such thing as a too big power trace
it decreases inductance, which this calculator doesn't take into account
red crow
why work in mils at all? personal preference
I aim for 0.8mm for power (0.6 minimum if it's tight), dunno about mils
halcyon river
I base my measurements from this article, 1st section
Remember this is low power anyway, the whole board won't draw more than 1A
Upgraded to .4mm
red crow
1-2mm if it's really close (like this) #kicad-schematic message
halcyon river
1mm !!!! This is huge!!!!
This is going to ruin my layout!
Why does the article I sent here says to avoid wide traces if possible and you say the opposite
late cobalt
if you read the article (I just checked to figure out which part you mean) he says
You always want to use the narrowest features you can with no extra cost to get the highest routing density.
So use narrow traces to save space
for power that is
a power plane (that you could do on 6l) would basically be a 52mm wide trace on your board ^^
halcyon river
I'd need a double power plane, or should I say two power planes on the same layer
but I swear I've seen people here saying power plans are useless
late cobalt
power planes are comfortable
you wanna route power on low layer count boards to avoid having to add 1-2 layers for a power plane because more layers cost more
if you wanna go 6L anyway and your current stackup is
S/P
G
G
G
G
S/P
just do a power plane for the love of god lol
halcyon river
true lol
late cobalt
also check the other server xd
halcyon river
if you wanna go 6L anyway and your current stackup is
S/P
G
G
G
G
S/P
just do ...
power plane requires switching layers
late cobalt
and?
halcyon river
isn't that bad, or does that only apply to signal?
junior shoal
If you have 6 layers anyway, use one layer per voltage as a power plane
Ideally with gnd in between so you won't get cross-voltage-domain capacitive coupling
halcyon river
if you wanna go 6L anyway and your current stackup is
S/P
G
G
G
G
S/P
just do ...
You wanted me to do this then
Alright latest revision of the board
Still need a lot more silkscreen, don't know what to add more
halcyon river
My life is a lie....
I have to redo everything
I just learned that the ESP32S3 doesn't support A2DP for audio streaming
I have to use a regular ESP32
sigh
I can put this board to trash
maybe not
there is hope
Because the ESP32-MINI might have the exact same footprint as the ESP32S3
junior shoal
Because the ESP32-MINI might have the exact same footprint as the ESP32S3
do they have the same pinout though?
halcyon river
Nope....
I guess I'll just copy the project since this board ready for production anyway
halcyon river
I have to redo the whole board anyway, I need a USB to UART to use the ESP32
Well if that's the case I might use a WROOM or a WROVER
And USB to UART costs 2$
halcyon river
5$ with feeder fees
welp I guess it is how it is
A2DP is costly
This stuff is so old it doesn't even have half the pins of the ESP32 S3 mini
red crow
How did you find that the S3 doesn't have A2DP? I'm trying to follow the same reasoning you have (and other things like MMC, MAC) but it's not on their product comparator https://products.espressif.com/#/product-comparison
halcyon river
It's bluetooth low energy
I can try a sample code when getting back home in an hour but pretty sure I need Bluetooth 4.2 BR/EDR to get A2DP
halcyon river
Sadness...
halcyon river
Second board done, waiting on feedback
red crow
the "boot" and "reset" labels went missing
The infamous 1µ capacitor on the EN line is also missing Found C5 but the placement is questionable
I still would put JP1 before C2/C4 not after
What's D2/R11 doin'?
LED?
I'd add some solderjumpers around U1 so you can transform the layout from your schematic to my schematic #electronics message in case necessary, without difficult bodging
btw, why the 28-pin CP2102N and not the 24-pin? You don't need the extra functionality. Availability?
also, CP2102N GPIO.0 and 1 can be used as RX/TX activity LEDs if you program it using their IDE
^<image deleted> I recommend BJT over FET for the boot circuit though
fixed
halcyon river
slowly adding the missing silkscreen
halcyon river
I still would put JP1 *before* C2/C4 not after
Will do
halcyon river
What's D2/R11 doin'?
Power LED at the output of the ldo
Thank you very much for your valuable feedback
junior shoal
I have a tested open source PCB for a esp32 with uart bridge and the transistor stuff on my github if it helps
yup seems like I used BJTs too
this thing is so old kicad launched the "rescue symbols" dialog
so... KC5 days?
looks like I did the dataline jumpering like this
halcyon river
I'm also using BJTs, same transistors as in their schem
halcyon river
btw, why the 28-pin CP2102N and not the 24-pin? You don't need the extra functio...
I just used the same chip as in their schem, again I copied their schem, but yeah I guess I can use the smaller version
red crow
i noticed the bigger version is missing the VIO pin. It should be connected to VDD if present.
just don't use the smallest of the three, it has four sneaky hidden pads (so it's part QFN part LGA (Land Grid Array))
halcyon river
i noticed the bigger version is missing the VIO pin. It should be connected to V...
like so?
Seems sketchy
red crow
VDD is like VREGOUT, but if you power the 3V3 reg with 3V3 you're telling it, 'don't reg, I'll provide it for ya'
halcyon river
Okay I see
red crow
VIO is like a level shifter for the outputs
halcyon river
fixed
Okay, are the TX/RX LEDs open drain? I see your LEDs having the TXT RXT pins on the negative pin
red crow
yes
halcyon river
Other small question, why are you putting your resistors after the LEDs and not before?
halcyon river
Yeah I need to run the LEDs at 1mA since I'll be using 0805s LEDs
Alright, how's my USB to UART looking now?
red crow
that meander doesn't look correct
consider that distance to B7 is longer than to A7
and that blob between the three power pins looks ugly. you don't need 1A for an UART
halcyon river
I should adjust distance before the TVS
red crow
distance adjust is not necessary at all
halcyon river
What is the blob
red crow
worse, C1/C3 are not near U1 but cut off by the usb lines
halcyon river
Okay I see
red crow
blob
halcyon river
Better?
late cobalt
worse, C1/C3 are not near U1 but cut off by the usb lines
imma be honest thats also just annoying pin layout by the manufacturer, data betwen supply and gnd? basically mandates vias on usb
halcyon river
Or getting thin traces btween the pads of caps
red crow
the caps can be moved under the tracks whole
no need to blame pinout for not being wrong
halcyon river
Data lines are going to get much longer
red crow
nah, the resistors can be moved down a lot
halcyon river
I dno't see where do you want me to put them
late cobalt
no need to blame pinout for not being wrong
im not blaming the pinout for bad routing, im just saying with a different pinout good routing would have been more straightforward, personally id probably just put decoupling on bottom side but with single side assembly its a bit meh
red crow
place the caps where R8 currently is
halcyon river
I can also put caps on top and perfectly fit data lines between their pads
I just checked and there is enough space
red crow
you can also move R1/R2 to the other side of the TVS altogether and route usb lines above
red crow
I just checked and there is enough space
what why?
halcyon river
So I put caps directly on top of U1 and route USB between
halcyon river
you can also move R1/R2 to the other side of the TVS altogether and route usb li...
good call
red crow
we need collaborative kicad editing like google docs
red crow
you can rotate them 180 and move them in line with resistors (looks nicer)
and remove via and wire directly from pins to caps
halcyon river
Now I wouldn't call this perfect but it's too far to my eyes
Only missing the memo silkscreen on the back from UART pins, I2C pins, etc
red crow
||those misaligned texts "GND" tickle my ocd||
why name pins VP and VN instead of their respective 36 and 39?
halcyon river
||those misaligned texts "GND" tickle my ocd||
they can't be misaligned I would have seen it lmao
you are right
halcyon river
why name pins VP and VN instead of their respective 36 and 39?
I don't know, that's how they are named on the devkit
3D render because why not
red crow
${KICAD8_3DMODEL_DIR}/Button_Switch_SMD.3dshapes/SW_SPST_TL3342.step
junior shoal
Also need to find the USB c port
I have one in marbastlib if that helps
halcyon river
I got my cheatsheet done
halcyon river
Was a good move to switch to that module, I could not have soldered the ESP32S3 which has pads beneath the modules
red crow
what's "Standard" PCBA service?
junior shoal
what's "Standard" PCBA service?
economic is what jlc assembly used to be
just with more limitations on component choice
standard has more features, can do 2 sided, you can order parts from mouser etc to it, but it costs extra
and quite a bit too
red crow
ikr
junior shoal
should have named economic "standard", and standard "pro"
since economic replaced what used to be normal
honestly, pretty annoyed at jlc recently. they keep paywalling parts behind extra fees and standard assembly that used to be basic cheap parts
their PCBs are still dirt cheap, but depending on what you need, assembly for 5 units can almost reach pcbway prices between extended fees, surcharges for weird reason, standard fees....
and their quality is simply not on a level to warrant such a price
red crow
This board uses one of those "Standard-only" (?) WROOM modules and PCBA of 258 parts, cost is almost negligible. I wonder if anything changed since? (this was 1.5y ago)
that's PCBA cost, not PCB cost (oops)
junior shoal
USB/BLE keyboard, kept as much basic as possible
red crow
this is more like it
junior shoal
led control thingy, that's with esp32-c6-mini modules ordered from mouser and paid for separately
on that one the BOM cost is actually rather high, so I can understand the price
on the keyboard it is wild 😄
late cobalt
still only €2.20 per pcb
aeris is young and broke
late cobalt
I'd assume it's about learning pcb design, not having the devkit xD
they wanna build a cd player or something
oh
well the thread is called cd player so I think so
halcyon river
Yeah, because if it works I'll just reuse the design
I'm splitting this big project in smaller tasks
And I'm not paying 25$ just to be able to assemble the WROOM
I'll do it myself since it's a castellered module
halcyon river
Building a CD player based on a old CD drive, project split in multiple tasks (n...
This ^
red crow
3D render because why not
Just noticed, but why are the RX and TX LEDs not at the edge (swap with their resistor)
halcyon river
easier routing
