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

Japanese TrueType font 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 I2C sensor connection to GPIO 18 and 19 (UNIT ENV III) - test_i2c_gpio1819.cpp
WebAssembly execution with Wasm3 (sample analog clock using AssemblyScript) - test_wasm3.cpp
Support RGB LED (SK6812)
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++ Extention 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.

📼 YouTube Demo(LCD)
📼 YouTube Demo(Wasm3)

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) + amazon.co.jp (2) + 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 v4.4.2

With esp-idf 4.4.1 and arduino-esp32 2.0.4 , DHCP for WiFi did not work correctly. For this reason, We are using esp-idf 4.4.2. But although it is not the correct combination. @see DHCP client failed on 2.0.4 #7068

I (4407) esp_netif_handlers: sta ip: 255.255.255.255, mask: 255.255.255.255, gw: 255.255.255.255

get_idf or (Windows) ESP-IDF 4.4.2 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 8.4.0 (crosstool-NG esp-2021r2)

openocd (Optional)

$ openocd
Open On-Chip Debugger  v0.10.0-esp32-20211111 (2021-11-10-21:40)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html

Build and Execute

git clone and build

git clone --recursive https://github.com/h1romas4/m5stamp-c3dev
cd m5stamp-c3dev
idf.py build 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 (AssemblyScript Analog Clock)

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

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 Partation file

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

Write NVS Partation

esptool.py write_flash 0x9000 nvs_partition.bin

Restart M5Stamp C3 (NTP synchronization is performed by pressing the SW1 after the startup logo)

idf.py monitor

Select connected GPIO18 and GPIO19 device

idf.py menuconfig

JTAG debug with Visual Studio Code

Set 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 parteation file

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
npm install

Web Browser Development

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

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.

Name	Version	License
esp-idf	`v4.4.2`	BSD License
esp32-arduino	`2.0.4`	LGPL-2.1 License
M5EPD	`0.1.4`	FreeType Part(The FreeType License)
UNIT_ENV	`0.0.5`	MIT License
Adafruit_GFX	`1.11.3`	BSD License
Adafruit_BusIO	`1.13.1`	MIT License
Adafruit-ST7735-Library	`1.9.3`	MIT License
Adafruit_NeoPixel	`1.10.5`	LGPL-3.0 License
tinyPNG	`0.11`	MIT License
TinyGPSPlus	`v1.0.3`	LGPL
wasm3	master(`dc9fa49`)	MIT License
AsselblyScript	`0.20.16`	Apache-2.0 License
源真ゴシック	-	SIL Open Font License 1.1

License

MIT License (includes PCB data and example source)

MaxGraey / m5stamp-c3dev