Pandapute

I started arranging the stuff on the PCB, but today i had a lot to do other than techie stuff,
and went out with friends, then got my wallet stolen D: . Anyway after all that stress i wasn’t really feeling like
working on the project, but i didn’t wanna lose my streak so i did a little bit

i powered through arranging the key matrix properly, with all the diodes correctly aligned with the correct keys, and this was probably the most satisfying
part of the project - i think it looks neat

then i started arranging like the Headers and stuff

after that came the Audio section - and look at how tiny those chips are - im getting anxiety let alone looking at them, and am trying not to think about tryna
wire and then solder those tiny ass pins - look at that chip in comparison to a capacitor:

also i did the display part and used a 3D model i found of the component for measurements - i think its accurate enough

i also arranged a lil bit on the ESP and the like boot/power/key switches :

the rest i will do tomorrow - im really putting off placing the capacitors and resistors cause thats a pain in the ass -
id have to double check where every one goes cause the airwires go crazy cause of the Net labels i used and cause most of them are
decoupling capacitors, i have to check the schematic on how/where to place them, and im not looking forward to it.

Anyway thats all for today, see ya tmrw !

Yeah so i imported, adjusted and assigned every component, and then added everything to the PCB
I then exported everything as a PDF and gave it to an LLM so it could look over it and point out any errors.
I had some minor errors, like some Pads not connected to GND when theyt should have been and a wrong capacitor value, but otherwise
im pretty proud of myself.

Next is to arrange the components on the PCB - also it got recommended to me by the AI
to use a 4 layer PCB, as that lets me dedicate a layer each to GND and POWER - so i have less traces, and no spider nest - cause otherwise EVERY
GND or +3V/+5V connection would need a trace.

So today i wired the rest of the schematic !

I wired the entire audio sheet - including the mic, speakers, and audio jack : This includes the signal amplifier, the encoder, one stereo speaker, microphone, and also a headphone 3mm audio jack that unfortunately still plays stereo sound.
If you don’t no what the difference between stereo and audio sound is, stereo is : stereo is basically built for one type of audio (a single speaker), while stereo is designed for two sides, with both sides playing a bit differently

after that i started wiring the display (which i decided will also have touch) AND SD card slot - because they actually can come together as one module. cause i could’nt find a symbol for this special component, i just used a Pin connector each for both sides.

Next was the easiest, and probably most satisfying part : The keyboard matrix
The main goal with the Keyboard Matrix was to make it

• as compact and small as possible
• good looking
• low profile
• not too hard to type on
• use a small amount of GPIO pins

in the end, i was able to do all this by using this switch matrix scanner chip called the TCA8418RTWR that takes over all the keyboard matrix scanning :

In the End i decided to use a 32-Key layout with 4 rows and 8 coloumns :

Then came the last (and most fun) part - the Peripherals

I decided i wanted some fun stuff like:

• a 5-way nav switch (that is incorporated in the switch matrix to save GPIO pins)

• a tilt and movement sensor (accelerometer & barometer 2 in 1)

• headers so i can connect other components - i exposed 5 GPIO pins, I2C/Grove for OLEDs and sensors and stuff, and basic Power (3V, 5V, GND, direct battery)

I had wanted to add a rotary encoder, but my GPIO pins ended up occupied and i did not wanna get rid of the GPIO header just for this - also i feel like i uee keyboard shortcuts for everything anyway
next up is footprint assignment and then pcb design, but im rather worried about the footprint for my display + sd module
the problem is, this module has both touch, display, and an sd card, and i cannot find a footprint for that - i could find some that have only diplay and touch, but no SD, or display and SD, but touch unused -
because of this issue, i will just use 2 connectors that are just approx. where the connectors on the module are, and either

1. submit the design files with the approximate measurement, then order the component, buy it, measure where the connector should go, and then adjust my PCB design
   or
2. plug in only one side and use a cable for the other side.

Im done with the Pandapute. To any reviewers out there who are reading this - the reason i only have one hour logged is because i did NOT use lapse or outlook - instead i have a JOURNAL.md file (this is allowed). Currently support for these isn’t on the Platform yet, so for now i dont have any devlogs - for an accurate progress report please read my JOURNAL.md file in the linked repository

I am not familiar with any of this which is why it took long. This session was all about wiring the power section in KiCad — correcting mistakes from the last session, adding missing components, and finally getting a complete power tree on the schematic.

What I wired:

• IP5306: VIN→VUSB, SW→L1→BAT, VOUT→+5V, KEY→SW→GND, POWERPAD→GND, LED1→1k→LED
• AP2112K-3.3: VIN→+5V, EN→+5V, VOUT→+3.3V, GND→GND + decoupling caps
• ESP32-S3: 3V3→+3.3V, GND→GND, BOOT→SW→GND, EN→10k to +3.3V + 1µF to GND + SW→GND
• USB_D-/D+ labels connected to GPIO19/20
• Power switch on battery line
• Battery ADC (100k/100k divider + 0.1µF on GPIO1)
• Power LED (1k + LED on +3.3V)
• All C1–C5 caps placed correctly (10µF on VIN, 22µF on BAT/VOUT, 10µF on regulator I/O)

It took literal ages to wire this with soooo much troubleshooting help from gemini, deepseek, opencode and literally everything
Mostly it was the capacitors and resistors and looking at a trillion different stupid datasheets that never have accurate info or a simple
example circuit that pissed me off. also i just realized i would have to wire a differential pair and power lines on the PCB, which is good practice,
but also exactly what I was trying to avoid.
anyway, peace out, i think ima work on audio next

The project started out with me seeing a fellow maker friend using a cardputer, and i thought it was cool - but then i tried using it myself,
and the tiny keyboard drove me crazy and the screen was so small i needed glasses - not ideal. Since i wanted to build a Cyberdeck anyway but was laxking experience,
i thought i would try and make one from scratch to get some experience with this stuff, and i can get a grant from outpost.

Started out thinking “how hard can it be to build a Cardputer clone?” lol.

Went back and forth on where to buy stuff. Reichelt, Mouser, Amazon, Keycapsss, AliExpress — none of them have everything. Finally realized I should just design the PCB first and let JLCPCB/PCBWay assemble whatever they can, then I only buy the leftovers myself (switches, battery, display, speaker, keyboard stuff).

The plan: everything on a custom PCB, bare components, no dev boards. Took a while to get that through my head — kept getting suggested dev boards with displays attached. No. From scratch.

Spent way too long on AliExpress browsing parts. Added ESP32-S3-WROOM-1-N16R8 for €8.59, AMS1117 for pennies, a battery — then realized shipping was gonna kill me if I buy everything separate. So fine, JLCPCB will source the ICs, I’ll just get the mechanical stuff myself.