m5stamp-c3dev

Name: m5stamp-c3dev
Author: h1romas4

Multi-purpose View the repo

25 stars · 6 forksGitHub repo · as of 2026-11-11 18:07 UTC

Maintainer: h1romas4
Chip families: esp32-c3

Boards with a recipe, by trust tier

Unverified

Stamp-C3UnverifiedM5Stack
Flash Stamp-C3guidedread the caveat
Unverified esp-atlas asserts this board↔firmware link at the shown trust tier — it does not guarantee your specific unit or the current firmware version. Flashing can erase keys/config and can brick the device. At your own risk.
Caveat: Not a drop-in for a bare M5Stamp C3. m5stamp-c3dev is the example ESP-IDF firmware for the author's own carrier board built around the M5Stamp C3, and it expects that carrier's peripherals: an ST7735 display and an SD card on SPI (SCLK 4, MOSI 5, MISO 6; SD CS 1; LCD CS 7, DC 10, RST 8, per main/c3dev_board.h at commit 61b7518). Setup per the pinned README: ESP-IDF release/v5.1, a recursive submodule checkout, the project's partition table, and separately prepared font and Wasm SPIFFS images. Not verified: no current successful build confirmed and not tested on hardware for this atlas.

README

m5stamp-c3dev

This is a development board for the M5Stamp C3 (RISC-V/FreeRTOS).

Hardware

External USB-C port for JTAG debugging
Support for LCD panel and SD card
Selecting a power supply
Switch(GPIO9) to enter loader mode
Pin headers to expose usable GPIOs to the outside
The size is just Japanese business card

Sample Sources Included

TrueType font with Japanese output to LCD - test_freetype.cpp
Output PNG images in SD card to LCD - test_tinypng.cpp
NTP synchronization via WiFi connection - test_nvs_wifi.cpp
Test ADC on GPIO0
- UNIT Light - main.cpp
Test I2C on GPIO18, 19
- UNIT ENV III - test_i2c_gpio1819.cpp
- UNIT ULTRASONIC - test_i2c_gpio1819.cpp
Test UART on GPIO18, 19
- UNIT GPS - test_uart_gpio1819.cpp
WebAssembly execution with Wasm3
- Analog clock using AssemblyScript - test_wasm3_clockenv.cpp
- GPS GSV viewer using AssemblyScript - test_wasm3_gpsgsv.cpp
- 3D Cube Demo using AssemblyScript - test_wasm3_imu6886.cpp
Usage of SPIFFS, which stores TrueType fonts and .wasm binaries (parttool.py and spiffsgen.py tools)
Use of NVS (cryptographically enabled key value store) that stores WiFi passwords (nvs_partition_gen.py tool)
Building libraries and managing dependencies using the esp-idf build system
Visual Studio Code C/C++ Extension configuration and JTAG debugging configuration in conjunction with openocd
AssembyScript sharing method between web browser and microcontroller - wasm

This repository contains MIT Licensed PCB data and example programs.

Demo

Video

Web Simulation

🕸 AssemblyScript Analog Clock
🕸 AssemblyScript GPS GSV Viewer

Schematic

|#Unit|Name|Note|Where to get it| |----|----|----|----| |U1|AE-USB2.0-TYPE-C|USB 2.0 Type-C Break out board|akizukidenshi.com (JP)| |U2|M5STAMP-C3|M5Stamp C3|+ M5Stack
+ SWITCH SCIENCE (JP)| |U3|KMR-1.8SPI|KMR-1.8 SPI marked LCD and SD card interface|+ amazon.co.jp (1)
+ ja.aliexpress.com| |R1 - R2|5.2K Resistor|Pull-down for USB Power supply|-| |R3 - R7|10K Resistor|SPI pull-up|-| |JP1|Jumper pin|Select external power supply|akizukidenshi.com (JP)| |SW1|Tact switch|for loader mode and utility|akizukidenshi.com (JP)| |J1|12 Pin header|You can use the one that comes with the M5Stamp C3 Mate|-|

PCB and Gerber data

Example Source

Require

Setup ESF-IDF release/v5.1

get_idf or (Windows) ESP-IDF command prompt

# Linux or macOS ->
$ alias get_idf='. $HOME/esp/esp-idf/export.sh'
$ get_idf
# <-

Detecting the Python interpreter
... snip ...
Done! You can now compile ESP-IDF projects.
Go to the project directory and run:

  idf.py build

$ echo ${IDF_PATH}
/home/hiromasa/devel/toolchain/esp/esp-idf

$ riscv32-esp-elf-gcc -v
Using built-in specs.
COLLECT_GCC=riscv32-esp-elf-gcc
... snip ...
gcc version 12.2.0 (crosstool-NG esp-12.2.0_20230208)

openocd (Optional)

$ openocd -v
Open On-Chip Debugger v0.12.0-esp32-20240318 (2024-03-18-18:25)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html

Build and Execute

git clone and build (Please add --recursive)

git clone --recursive https://github.com/h1romas4/m5stamp-c3dev
cd m5stamp-c3dev
idf.py build

Note: If you get a compile error, change the sdkconfig back to the Git one. In some cases, the target of sdkconfig is changed to esp32 instead of eps32c3.

Write Partition table

idf.py partition-table-flash

Write TypeType font to SPIFFS

parttool.py write_partition --partition-name=font --partition-subtype=spiffs --input resources/spiffs_font.bin

Write WebAssembly(.wasm) to SPIFFS

parttool.py write_partition --partition-name=wasm --partition-subtype=spiffs --input resources/spiffs_wasm.bin

Write main program to go!

idf.py flash monitor

Setup WiFi (Optional)

Change WiFi Setting

nvs_partition.csv: Set own [ssid], [password]

key,type,encoding,value
wifi,namespace,,
ssid,data,string,[ssid]
passwd,data,string,[password]

Create NVS Partition file

python ${IDF_PATH}/components/nvs_flash/nvs_partition_generator/nvs_partition_gen.py generate nvs_partition.csv nvs_partition.bin 0x6000

Write NVS Partition

esptool.py write_flash 0x9000 nvs_partition.bin

NTP synchronization is performed by pressing the SW1 after the startup logo.

idf.py monitor

Select connected GPIO18 and GPIO19 device (Optional)

idf.py menuconfig

C3DEV Configuration → Select GPIO 18/19

3D Cube Demo

JTAG debug with Visual Studio Code

Require setup ESP32_TOOLCHAIN_HOME

$ echo ${ESP32_TOOLCHAIN_HOME}
/home/hiromasa/.espressif/tools/riscv32-esp-elf

Connect the PC to the USB Type-C of the U1
Open the source file in Visual Studio Code.
Run Task "openocd (debug)" @see .vscode/tasks.json
Set a breakpoint in the source code.
Debug Launch (GDB) @see .vscode/launch.json The first time you start the program, it will often fail, so if you get an error, retry.

Note

If the LCD color is inverted.

main/main.cpp

    // If the color is inverted, set to 1.
    tft.invertDisplay(0);
    // tft.invertDisplay(1);

Create SPIFFS partition file from file system

python ${IDF_PATH}/components/spiffs/spiffsgen.py 0x100000 resources/font resources/spiffs_font.bin
python ${IDF_PATH}/components/spiffs/spiffsgen.py 0x10000 resources/wasm resources/spiffs_wasm.bin

Change the output destination of the log to U1 Serial/JTAG.(Don't forget to put it back)

Component config → ESP System Settings → Channel for console output

idf.py menuconfig

AssemblyScript and Wasm3

Build AssemblyScript

cd wasm/clockenv # or wasm/gpsgsv or wasm/imu6886
npm install

Web Browser Development

npm run asbuild:web
npm run start
# http://localhost:1234/

SPIFFS Build and Flash

npm run asbuild
cd ../../
python ${IDF_PATH}/components/spiffs/spiffsgen.py 0x10000 resources/wasm resources/spiffs_wasm.bin
parttool.py write_partition --partition-name=wasm --partition-subtype=spiffs --input resources/spiffs_wasm.bin

Dependencies

Thanks for all the open source.

License

MIT License (includes PCB data and example source)

Read the full README on GitHub

source github.com/h1romas4/m5stamp-c3dev