2 layers103 × 30.5 mm
2 layers56 × 69.5 mm
Tomodachi
yotepanda/tomodachilittle panda guy
- Size
- 56 × 69.5 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 9
- Nets
- 22
- Pads
- 55
- Tracks, vias
- 82, 3
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 8 May 2026
- Updated
- 11 May 2026
Overview
Tomodachi is an open-source printed circuit board by yotepanda, from the yotepanda/tomodachi repository on GitHub. It is a 2-layer board of 56 × 69.5 mm with 9 parts on 22 nets, routed with 82 tracks and 3 vias.
It belongs with the ESP32 and RISC-V boards of this library.
README
README.mdtomodachi
Tomodachi is a project to give you a heavily dependent and lazy panda to take care of, made because I need hardware and CAD design experience plus coding in firmware and also making panda themed gadgets is one of the coolest activities of all time
What the panda can do:
- Eat the food you give them (until they don't feel like it)
- Be head patted
- Perish
Features hand-drawn animations (more animations will come out once project is approed since I need the RTC to test more)
materials
| Name | Quantity | Purchase link |
|---|---|---|
| ESP32C3 | 1 | XIAO ESP32C3 DIP link |
| DS3231 RTC | 1 | DS3231 RTC link |
| Coin battery (for RTC if not included) | 1 | Coin battery link |
| 0.96in SSD1306 (128x64) | 1 | SSD1306 (128x64) |
| TP4056 | 1 | TP4056 link |
| Shottky diodes | 2 | this was the cheapest & most appropriate I could find -> Schottky diodes link |
| KY-040 Rotary Encoder | 1 | KY-040 Rotary encoder link |
| SS12F44 Switch | 1 | SS12F44 Switch link |
| Battery 18650 3.7V | 1 | 18650 battery link |
| Wires |
(the material links were used assuming the fallout team has amazon prime for free shipping)
design
PCB Schematic
^note that the part labeled E1 is because Kicad was mad I have the SS12F44 switch connected by wires instead of traces, please ignore
PCB Footprint
Case
assembly
steps:
- 3d print the case, case cover and panda ears
- PLA is going to be used in this project but recommended to use a more stronger & less brittle filament for snap fits
- Flash the firmware by using Arduino IDE:
- Download the firmware folder and place the firmware folder inside a dedicated folder
- Unzip the libraries.zip and place "libraries" folder in the dedicated folder (named exactly that)
- Go to Arduino IDE File > Preferences and set the library folder to libraries
- Connect the XIAO ESP32C3 DIP to the computer with a USB-C cable, select the port that pops up and set the board as a "XIAO_ESP32C3"
- Go to "tomodachi_sketch.ino" and compile and upload
- Solder the components to the PCB
- Use header pins to connect the throughholes on both the pcb and components for easier soldering (though tinning the holes will work too)
- Make sure to insert the coin battery into the RTC after soldering (heat damage might hurt the battery)
- Solder a wire from the bottom left corner pad marked "CONNECT TO SWITCH" (not the throughholes connected to the D2 schottky diode) to one end of the SS12F44 switch's three pins, and then solder a wire from the Out+ of the TP4056 component (also marked with "CONNECT TO SWITCH") to the middle pin on the SS12F44 switch's three pins
- The SS12F44 connects the middle pin with one or the other of the three pins depending on where it is switched
- Use a short length wire when soldering the two places, and wrap each connection in electrical tape to ensure no short circuits happen
- For both of the mentioned throughholes on the PCB probably don't use header pins as it will be easier to solder a wire without them
- Place the battery in the case first, then solder the wire from the battery's + end to the TP4056's 5V hole, and the battery's - end to the TP4056's GND hole (both located on the edge of the PCB)
- Assemble case with cover and ears
Parts
9| Qty | Value | Footprint | References |
|---|---|---|---|
| 2 | D_Schottky | Resistor_THT:R_Axial_DIN0309_L9.0mm_D3.2mm_P20.32mm_Horizontal | D1, D2 |
| 1 | KY-040 | tomodachi:KY-040-PORT | KY-040 |
| 1 | TC00500 | tomodachi:MODULE_TC00500 | DS3231 |
| 1 | XIAO-ESP32-C3-DIP | tomodachi:XIAO-ESP32-C3-DIP | XIAO ESP32C3 DIP |
| 1 | ~ | tomodachi:TP4056-18650 | TP4056-1 |
| 1 | ~ | Connector_Wire:SolderWire-0.75sqmm_1x01_D1.25mm_OD3.5mm | E1 |
| 1 | ~ | tomodachi:SSD1306128x64OLED | SSD1306 |
The 8 most common of 9 parts.
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Questions
How big is the Tomodachi PCB?
It measures 56 × 69.5 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Tomodachi use?
9 parts. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Tomodachi KiCad files?
From the yotepanda/tomodachi repository on GitHub, at the commit this page was made from: the board is src/cad/kicad/tomodachi.kicad_pcb and its schematic src/cad/kicad/tomodachi.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Tomodachi design in my own project?
Its repository states no licence, so its author keeps all rights: ask yotepanda before reusing the design.