Raspberry Pi Pico SDK

The Raspberry Pi Pico SDK provides the headers, libraries, and build system required to develop programs for RP-series microcontroller devices (like the Raspberry Pi Pico) using C, C++, or assembly language.

Key features include:

• Support for standard C and C++ libraries.
• APIs for hardware access: DMA, IRQs, fixed-function peripherals, and PIO (Programmable IO).
• High-level libraries for: Timers, USB, synchronization, and multi-core programming.
• High-level PIO-based functionality (e.g., audio).
• Ability to build everything from simple apps to full runtimes like MicroPython.

The SDK provides two distinct layers of libraries for targeting RP2040, RP2350, and future devices:

1. hardware_ libraries: These provide a thin abstraction layer for individual hardware components. They offer a simple API to interact with hardware without requiring you to access hardware registers directly.
2. pico_ libraries: These provide higher-level functionality, including runtime support for C programmers and features typically found in an OS kernel.

When building for RP2350 hardware, you must specify the appropriate platform using the PICO_PLATFORM environment variable or CMake configuration. The available RP2350 platforms are:

• rp2350-arm-s
• rp2350-riscv

The host platform provides a set of replacement library implementations that allow you to run simple applications on your computer (Raspberry Pi OS, Linux, macOS, or Windows via Cygwin/WSL) instead of the RP2040 or RP2350 hardware. This is useful for testing high-level application logic or porting code before deploying to physical hardware.

Note that the base host library provides a minimal environment and is best suited for programs that do not access hardware directly.

To build projects using the Raspberry Pi Pico SDK on a Linux-based system, install CMake (3.13+), Python 3, build-essential, and the ARM GCC cross-compiler toolchain.

sudo apt install cmake python3 build-essential gcc-arm-none-eabi libnewlib-arm-none-eabi libstdc++-arm-none-eabi-newlib

If you have added the SDK as a Git submodule named pico-sdk, use pico_sdk_init.cmake from the submodule directory.

Note: The include call must occur before the project() command.

cmake_minimum_required(VERSION 3.13...3.27)

# initialize pico-sdk from submodule
# note: this must happen before project()
include(pico-sdk/pico_sdk_init.cmake)

project(my_project)

# initialize the Raspberry Pi Pico SDK
pico_sdk_init()

# rest of your project

If you have cloned the SDK locally, copy pico_sdk_import.cmake from the SDK's external/ directory into your project directory. You must then set PICO_SDK_PATH in your environment or pass it to CMake via -DPICO_SDK_PATH=.

Note: The include(pico_sdk_import.cmake) call must occur before the project() command in your CMakeLists.txt.

cmake_minimum_required(VERSION 3.13...3.27)

# initialize the SDK based on PICO_SDK_PATH
# note: this must happen before project()
include(pico_sdk_import.cmake)

project(my_project)

# initialize the Raspberry Pi Pico SDK
pico_sdk_init()

# rest of your project

To build for the RISC-V architecture on RP2350, you must install the prebuilt toolchain and set the PICO_TOOLCHAIN_PATH and PICO_PLATFORM environment variables.

1. Download and extract the toolchain (example for v2.0.0-5):

wget https://github.com/raspberrypi/pico-sdk-tools/releases/download/v2.0.0-5/riscv-toolchain-14-aarch64-lin.tar.gz
sudo mkdir -p /opt/riscv/riscv-toolchain-14
sudo chown $USER /opt/riscv/riscv-toolchain-14
tar xvf riscv-toolchain-14-aarch64-lin.tar.gz -C /opt/riscv/riscv-toolchain-14

2. Set environment variables:

export PICO_TOOLCHAIN_PATH=/opt/riscv/riscv-toolchain-14/
export PICO_PLATFORM=rp2350-riscv