Raspberry Pi Pico Setup for macOS

Install required dependencies

First off we have to install a couple of tools so we can actually build the Pico C/C++ SDK:

• Make
• Cmake
• GCC ARM Cross-Compiler
• Git
• Libusb

For easier installation we will use the Brew package manager. If you don't already use it you can install it by following their setup guide: https://brew.sh/index

With Brew setup, we can run the following command to install all required dependencies:

          brew install gcc-arm-embedded libusb make cmake git

Get the Pico SDK

In our workspace lets create a new folder called pico to contain all related tools:

          mkdir pico

We can then change into this directory and checkout the pico-sdk from Github: https://github.com/raspberrypi/pico-sdk

          git clone https://github.com/raspberrypi/pico-sdk.git

This is going to take a little bit as it downloads the whole project. Once the checkout procedure is done we still need to do a last initialization step as the pico-sdk project manages its dependencies as Git submodules. So we can execute

          git submodule update --init

to fetch all referenced submodules.

Create and build our project

Now we are ready to create our very own project in the root of our workspace. As a starting point we are going to use the blink example from the pico-examples repository.

You can clone it to any location but I like to keep it in the local pico folder as well:

          cd pico
          git clone https://github.com/raspberrypi/pico-examples.git

We can then simply copy the example folder to root of our workspace:

          cd ..
          cp -r pico-examples/blink .

Make sure to use the examples in the pico_w directory if you have a Pico W board otherwise they won't work correctly.

This should leave us with a directory structure like this:

          tree -L 2
          .
          ├── blink
          │   ├── CMakeLists.txt
          │   ├── blink.c
          │   ├── build
          │   └── pico_sdk_import.cmake
          └── pico
          ├── pico-examples
          └── pico-sdk

We still need some other files to satisfy build process. Namely the pico_sdk_import.cmake file to initialize the Pico SDK and a CMakeLists.txt to handle the actual build process. The former can be copied from the pico-exampels project and an example of the latter can be found on Github.

Now we have everything setup to actually build this example and push the generated binary to our development board.

First we have to create a build directory where our binary will be located after the build finishes:

          cd blink
          mkdir build

Next we need to set two environment variables that are required by the build process:

          cd build
          export PICO_SDK_PATH=../../pico/pico-sdk
          export PICO_BOARD=pico
          # export PICO_BOARD=pico_w

With this out of the way we can finally build our program with the help CMake and Make like this:

          cmake ..
          make

After the compilation process is done we should have a file called blink.uf2 in our build directory.

Uploading our binary

Last but not least, we actually need to transfer our program to the Raspberry Pi Pico board.

To do this we grab our trusty micro USB cable and connect it to our development machine. Next we hold down the BOOTSEL button on our Pico and connect the other end of our USB cable while still holding the button down.

The Raspberry Pi Pico will now show up as a mass storage device and we can simply copy our binary over. The microcontroller will then restart by itself and start running our program.

That's it, you've successfully run your first Raspberry Pi Pico program!

Enhancing the build process

With this setup we have some manual steps that need be repeated every time we change our code. First and foremost unplugging the Raspberry Pi Pico all the time to get it into BOOTSEL mode.

Luckily for us their is a better solution using a project called picotool which we will check out in the next post.