RaspberryPi rp2040

The rp2040 is a dual core chip produced by the RaspberryPi Foundation that is based on ARM Cortex-M0+.

Peripheral Support

The following list indicates peripherals currently supported in NuttX:

Peripheral

Notes

GPIO

See Supported Boards documentation for available pins.

UART

GPIO 0 (UART0 TX) and GPIO 1 (UART0 RX) are used for the console.

I2C

SPI

DMAC

PWM

USB

PIO

RP2040 Programmable I/O

IRQs

DMA

Clock Output

ws2812

Smart pixels (e.g. Neopixel)

Flash ROM Boot

SRAM Boot

If Pico SDK is available a nuttx.uf2 file will be created

BMP180

Requires I2C0

INA219

Requires I2C0

The Pico Display Pack (ST7789 LCD) and Pico Audio Pack (PCM5100A I2S DAC) are also available.

Installation

  1. Download Raspberry Pi Pico SDK:

  2. Set PICO_SDK_PATH environment variable:

    export PICO_SDK_PATH=<absolute_path_to_pico-sdk_directory>

  3. Download NuttX and the companion applications. These must both be contained in the same directory:

    git clone https://github.com/apache/nuttx.git nuttx
git clone https://github.com/apache/nuttx-apps.git apps

Building NuttX

  1. Change to NuttX directory:

    cd nuttx

  2. Select a configuration. The available configurations can be listed with the command:

    ./tools/configure.sh -L

  3. Load the selected configuration.:

    make distclean
./tools/configure.sh <selected_configuration>

  4. Modify the configuration as needed (optional):

    make menuconfig

  5. Build NuttX:

    make

Programming

Programming using BOOTSEL

Connect board to USB port while pressing BOOTSEL. The board will be detected as USB Mass Storage Device. Then copy “nuttx.uf2” into the device. (Same manner as the standard Pico SDK applications installation.)

Programming using SDB

Most (but no all) RP2040 boards provide a serial (SDB) debug port. The “nuttx” ELF file can be uploaded with an appropriate SDB programmer module and companion software.

Running NuttX

Most builds provide access to the console via UART0. To access this GPIO 0 and 1 pins must be connected to the device such as USB-serial converter.

The usbnsh configuration provides the console access by USB CDC/ACM serial devcice. The console is available by using a terminal software on the USB host.

Supported Boards