This directory contains example code for the Pololu 3pi+ 2040 Robot written in C. Most of the code depends on the [Pico SDK].
The pololu_3pi_2040_robot directory contains a library of functions
that help access various components of the robot.
The include directory holds the include files for the library.
Install the tools you need to build this code: Git, CMake, GNU Make, a native
GCC toolchain, an arm-none-eabi-gcc toolchain, and Python 3.
| Operating system | Command |
|---|---|
|
Microsoft Windows with MSYS2 |
|
| macOS (untested) |
Install Homebrew, then do: |
| Debian Linux / Ubuntu |
|
| NixOS / Nix |
|
Use Git to download this repository (if you don't already have it) and navigate to this directory:
git clone https://github.com/pololu/pololu-3pi-2040-robot
cd pololu-3pi-2040-robot/c
Use Git to download the Pico SDK and the tinyusb submodule. (If you don't want
to store the Pico SDK in this location, you can set the PICO_SDK_PATH
environment variable to point to a copy of the Pico SDK somewhere else.)
git clone https://github.com/raspberrypi/pico-sdk
git -C pico-sdk submodule update --init lib/tinyusb
Make a build directory and use CMake to configure and build one of the example projects in it:
cd blink
mkdir build
cd build
cmake ..
cmake --build .
When changing your code, you just need to re-run the last line.
(Alternatively, you can run make or ninja to build the project, depending on
what system you are using.)
CMake will produce three binary files containing the compiled program:
a simple binary image with a .bin extension, a .uf2 file that works with
the RP2040's USB bootloader, and a .elf file that includes debugging
information.
MSYS2 users: If CMake reports an error while generating
bs2_default_padded_checksummed.S, it might be using the wrong Python
interpreter, which causes issues with Windows/POSIX path conversions.
Look at the output from the first CMake command and see if it found Python
in the /usr/bin folder inside MSYS2.
If so, delete your build directory and try again, and this time
append -DPython3_EXECUTABLE=$(which python3) to the first CMake command.
Connect your 3pi+ 2040 Robot to your computer via USB and get it into BOOTSEL
mode by pressing and releasing the Reset button while holding down button B.
In this mode, the RP2040 presents itself to the computer as a
USB Mass Storage Device. You can load the code you compiled onto the robot
by copying the .uf2 file to the RP2040, the same way you could copy a file
onto a USB thumb drive.
For example, a complete command for building and loading the code might be:
cmake --build . && cp blink.uf2 /e
For more control over the upload process, you can install picotool
and use it to load the .bin, .uf2, or .elf file (it doesn't matter which)
onto the robot:
picotool load -x blink.uf2
After you load the code onto your robot using either of these methods, the robot will start executing the code.
You can move pico-sdk and the pololu_3pi_2040_robot library into different locations, for example making them subdirectories of your project. If you do that, update the paths starting with "../" in your CMakeLists.txt.