How to set up Rust for BBC micro:bit on Ubuntu

help
1

Hi, I followed this video to set up an environment to write Rust code for the BBC micro:bit

I was successful until running cargo embed. I get the error message:

cargo embed --chip nRF52833_xxAA
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.03s
      Config default
      Target /home/markus/dev/rust/hello/target/thumbv7em-none-eabihf/debug/hello
       Error Probe could not be created
             
             Caused by:
                 0: hidapi error: Failed to open a device with path '/dev/hidraw3': Permission denied
                 1: hidapi error: Failed to open a device with path '/dev/hidraw3': Permission denied

/dev/hidraw* are all owned by root. So far, so good. But I don't know which permissions I should set.

I changed the owner to my user, which works. But wouldn't it be better to change the group? But which group?

2

Try running ls -l /dev/hidraw* and look which group they belong to. Also check whether your distro is using udev and if they have rules for your device.

3

Group is also root. I'm running Ubuntu and I don't know of any udev rules for the micro:bit

4

I have this in /etc/udev/rules.d/99-microbit.rules, and it is now working:

SUBSYSTEM=="usb", ATTR{idVendor}=="0d28", ATTR{idProduct}=="0204", MODE:="666"
SUBSYSTEM=="hidraw", MODE:="666"

I confess I don't know how all this works.
I think the second line will give RW permissions on all hidraw devices, but I couldn't work out a way to make it more specific.
Leaving the idVendor and idProduct stuff on there as well didn't work, I guess because they're identifiers for the USB subsystem.
Anyway, this got me working, hopefully you too.

5

You are right. Sometimes it could be so easy

6

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