Raspberry Pi Pico, Pico W, Pico 2 (RP2350, Arm or RISC-V), Waveshare RP2040-Zero and every other RP2040 / RP2350 board.

1. Download from the latest release: microcs-<version>-pico.uf2 (Pico, Pico W, most RP2040 boards), microcs-<version>-pico2.uf2 (Pico 2) or microcs-<version>-waveshare_rp2040_zero.uf2.

2. Hold BOOTSEL, plug in the USB cable, release: a drive called RPI-RP2 (RP2350) appears. Copy the .uf2 onto it; the board restarts by itself.

3. Open the new USB serial port (any baud rate; Windows: COMx in the Device Manager, Linux /dev/ttyACM0, macOS /dev/cu.usbmodem…) with a terminal or MicroCS Studio (Chrome/Edge → Connect), press Enter:

   > var led = new Pin("LED", GPIO.Output);    // on-board LED (GP25 on the Pico)
   > led.Toggle();
   

The release firmware runs C# threads on both cores (FreeRTOS SMP) and keeps your files in LittleFS on the flash (1 MB on the Pico, 3 MB on the Pico 2).

• the pico-sdk 1.5 or 2.x (git clone -b 2.1.1 https://github.com/raspberrypi/pico-sdk && cd pico-sdk && git submodule update --init),
• the Arm GCC toolchain (arm-none-eabi-gcc), CMake 3.13+, Python 3, Ninja or make (Windows: the Raspberry Pi Pico Windows installer / VS Code Raspberry Pi Pico extension installs all of them).

git clone https://github.com/amir1387aht/MicroCS && cd MicroCS
export PICO_SDK_PATH=/path/to/pico-sdk
cmake -S ports/rp2/example -B build/pico -DPICO_BOARD=pico -DMICROCS_FS_DOWNLOAD=ON
cmake --build build/pico -j

PICO_BOARD=pico2 for the Pico 2, pico_w for the Pico W. MICROCS_FS_DOWNLOAD=ON fetches LittleFS v2.9.3 once; -DMICROCS_FS=tinyfs uses the built-in TinyFS instead (nothing to fetch). Copy build/pico/microcs_pico.uf2 to the board as in path A.

Useful options on the same cmake line:

The buses use the Pico pin-out by default — UART0 GP0/GP1, UART1 GP4/GP5, I2C0 GP8/GP9 (SDA/SCL), I2C1 GP6/GP7, SPI0 GP18/GP19/GP16 (SCK/MOSI/MISO), SPI1 GP10/GP11/GP12. Other pins: edit ports/rp2/example/main.c before mcs_rp2_hal_init:

mcs_rp2_cfg_t pins = MCS_RP2_CFG_DEFAULT;
pins.i2c[0] = (mcs_rp2_i2c_pins_t){ 4, 5 };     // SDA, SCL

Every GPIO can do PWM (PWM.Set(15, 1000, 0.5) = GP15), ADC.Read(0..3) reads GP26–GP29 and ADC.Read(4) the temperature sensor.

python3 tools/mcs_remote.py --port /dev/ttyACM0 put blink.cs /main.cs + run /main.cs

/main.cs then runs at every start. With Studio: Connect → write → Save & Run.

More: ports/rp2/README.md (pins, files, both cores).