Raspberry Pi Pico/RP2040 udev rules

99-pico.rules

# /etc/udev/rules.d/99-pico.rules

# Make an RP2040 in BOOTSEL mode writable by all users, so you can `picotool`
# without `sudo`. 
SUBSYSTEM=="usb", ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="0003", MODE="0666"

# Symlink an RP2040 running MicroPython from /dev/pico.
#
# Then you can `mpr connect $(realpath /dev/pico)`.
SUBSYSTEM=="tty", ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="0005", SYMLINK+="pico"

Then reload with the following:

sudo udevadm control --reload-rules && sudo udevadm trigger

---

The official/comprehensive udev rules for all raspberry pis can be seen in the picotool repo:

https://github.com/raspberrypi/picotool/blob/master/udev/99-picotool.rules

This udev (and the tool) are included in the picotool Debian package, which is currently available in the Debian testing repo:

https://packages.debian.org/trixie/picotool

sudo apt install picotool

For Pico2 featuring the RP2350 chip, I started getting picotool complaints like:

RP2350 device at bus 1, address 36 appears to be in BOOTSEL mode, but picotool was unable to connect. Maybe try 'sudo' or check your permissions.

I needed to add

SUBSYSTEM=="tty", ATTRS{idVendor}=="2e8a", ATTRS{idProduct}=="000f", SYMLINK+="pico"

I.e. the entry has to be almost duplicated, just taking into account different idProduct. This shouldn't interfere with the rest of the trick.