arduino-steami-lib

Arduino/C++ driver library for the STeaMi board. Each driver lives under lib/<component>/ and follows a standard structure.

Repository contents

• Ready-to-use Arduino-compatible drivers
• Consistent API design across all components
• CI integration with clang-format and PlatformIO

Board components

Component	Driver	I2C Address	Description
BQ27441-G1	bq27441	0x55	Battery fuel gauge
DAPLink Flash	daplink_flash	0x3B	I2C-to-SPI flash bridge + config zone
SSD1327	ssd1327	— (SPI)	128x128 greyscale OLED display
MCP23009E	mcp23009e	0x20	8-bit I/O expander (D-PAD)
VL53L1X	vl53l1x	0x29	Time-of-Flight distance sensor
APDS-9960	apds9960	0x39	Proximity, gesture, color, light
HTS221	hts221	0x5F	Humidity + temperature
WSEN-HIDS	wsen-hids	0x5F	Humidity + temperature
WSEN-PADS	wsen-pads	0x5D	Pressure + temperature
ISM330DL	ism330dl	0x6B	6-axis IMU (accel + gyro)
LIS2MDL	lis2mdl	0x1E	3-axis magnetometer
IM34DT05	im34dt05 (not yet implemented)	— (PDM)	Digital microphone
BME280	bme280 (not yet implemented)	0x76	Pressure + humidity + temperature
GC9A01	gc9a01 (not yet implemented)	— (SPI)	Round color LCD display
STeaMi Config	steami_config	—	Persistent board configuration

Quick start

Prerequisites

• PlatformIO or Arduino IDE
• A STeaMi board

Build with PlatformIO

pio run

Upload to board

pio run --target upload

Development

Setup

Requires Python 3 (with venv — on Debian/Ubuntu: sudo apt install python3-venv) and Node.js (for the git hooks tooling).

make setup    # Install npm tooling, git hooks, and PlatformIO (in a local .venv/)

make setup creates a local Python virtualenv in .venv/ and installs PlatformIO there, so no global pip install is required. All make targets (build, upload, test-native, test-hardware) transparently use this local pio.

To use pio directly outside of make, activate the venv first:

source .venv/bin/activate
pio device monitor -b 115200

Available commands

Run make help to see all available targets:

Command	Description
make lint	Run clang-format check
make lint-fix	Auto-fix formatting
make build	Build with PlatformIO
make test-native	Run host-side unit tests (no board required)
make test-hardware	Run on-board unit tests (STeaMi required)
make upload	Upload to board
make clean	Remove build artifacts
make deepclean	Remove everything including node_modules

Git hooks

Git hooks are managed by husky and run automatically on commit:

• commit-msg — validates commit message format via commitlint
• pre-commit — branch name validation, content checks, clang-format on staged files

Troubleshooting uploads

PlatformIO's default uploader on STeaMi is OpenOCD over CMSIS-DAP. On Linux, the most common failure mode is Error: unable to find CMSIS-DAP device (or similar) caused by incomplete udev rules.

Install udev rules

The rules shipped with pyocd only grant access to the CMSIS-DAP v1 HID interface. OpenOCD prefers the CMSIS-DAP v2 bulk interface (accessed via libusb on Linux), which needs a separate rule on the USB subsystem. Install both, and tell ModemManager to stop probing the virtual serial port:

sudo tee /etc/udev/rules.d/60-steami.rules > /dev/null <<'EOF'
# STeaMi / ARM mbed DAPLink
# CMSIS-DAP v2 (bulk interface — used by OpenOCD by default)
SUBSYSTEM=="usb", ATTRS{idVendor}=="0d28", ATTRS{idProduct}=="0204", \
    TAG+="uaccess", ENV{ID_MM_DEVICE_IGNORE}="1"
# CMSIS-DAP v1 (HID fallback — used by pyocd and older OpenOCD)
KERNEL=="hidraw*", ATTRS{idVendor}=="0d28", ATTRS{idProduct}=="0204", \
    TAG+="uaccess"
EOF
sudo udevadm control --reload-rules && sudo udevadm trigger

Then unplug and replug the board.

Fallback: use pyocd instead of OpenOCD

If OpenOCD still fails after the udev rules, pyocd is a drop-in alternative with broader DAPLink firmware compatibility and bundled target definitions:

source .venv/bin/activate
pip install pyocd

Then edit platformio.ini:

upload_protocol = custom
upload_command = pyocd flash --target stm32wb55rgvx $SOURCE

The exact pyocd target name may vary by pack version — run pyocd list --targets | grep -i wb55 to confirm. You may need to install the CMSIS pack first: pyocd pack install stm32wb55.

Check OpenOCD version

PlatformIO bundles its own OpenOCD at ~/.platformio/packages/tool-openocd/bin/openocd. STM32WB55 support has improved across versions — if both remedies above fail, verify the bundled OpenOCD is recent:

~/.platformio/packages/tool-openocd/bin/openocd --version

Contributing

See CONTRIBUTING.md.

License

This project is licensed under the GPL v3 License.

Additional Resources

• STeaMi Official Website
• MicroPython driver library — sister project
• Arduino Documentation