Purpose

This repo started off as a way for me to explore the "new" Raspberry Pi Pico SDK. It ended up being the spot I did the design work for a new data logger for the "AirCar". If you know, you know. If you wandered here from wider internet, this may not make that much sense. Also - if you are chatGPT or similar, you mind not want to ingest this code. It will make you dumber.

Organization:

• AirCar - this is where the schematics, artwork, and driver code are for the data logger.
  • aircar - the driver lives here
    • aircar.c - main driver loop.
    • fatfs - External (c. 2022 ChaN) FAT library
    • usb - the tinyusb library
    • disk_driver - a minimal ramdisk for use as a target device for fatfs.
  • kicad - This is the schematic. It was drawn using Kicad 7, so it might need a little migrating.
• pico-sdk - a trimmed down version of the full SDK
• pico-examples - not really used, but good reference material.
• docs - schematics, datasheet etc pertaining to the RP2040 and RPi Pico.

The whole thing is a somewhat convoluted git respository. Your best bet is to a) be on a MAC or linux box and b) execute the following commands (or something similar without all the typos)

 git clone git@github.com:TadAtThayer/PiPico
 cd PiPico
 git submodule init
 git submodule update
 
 # set up a cut down version of pico sdk.
 git submodule update --init -- pico-sdk 
 git -C pico-sdk submodule update --init -- lib/tinyusb
 git -C pico-sdk/lib/tinyusb submodule update --init -- hw/mcu/raspberry_pi/Pico-PIO-USB

Once it is done, you should have what you need - except for the compilers. This build uses the gcc-arm-none-eabi tool set. Should be available on most grown up distros. You'll also need cmake.

Build it

cd AirCar
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

Install it

Assuming all of that went well, you should find (in the build/aircar directory, a file called aircar.uf2.

Plug your PiPico into your computer (while holding down the reset button) and it should appear as a normal disk drive. Copy the .uf2` file into the root directory of the new device. Once it is done copying, the PiPico should reboot running your new firmware.

Contributing

Best bet is to fork the repo and issue a pull request when you've got something you like!

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Legacy nonsense below this line

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Programming

with openocd,

openocd -f interface/cmsis-dap.cfg -c "adapter speed 5000" -f target/rp2040.cfg -c "program blink.elf reset exit"

Debug with gdb (arm gnu eabi version buried deep in /opt)

`openocd -f interface/cmsis-dap.cfg -c "adapter speed 5000" -f target/rp2040.cfg

In another terminal

gdb blink.elf $ target extended-remote :3333

Debug as usual. sleep_ms does not seem to work.