Hanging during initialization

[derrickgw]

I have run into a problem with some beta firmware where the code doesn't respond. I have created a minimal program that exhibits the bug.

This program never reaches the print statement:

from pybricks.hubs import PrimeHub
from pybricks.parameters import Direction, Port
from pybricks.pupdevices import Motor
from pybricks.robotics import DriveBase

# Set up all devices.
# prime_hub = PrimeHub()
# right_wheel = Motor(Port.D, Direction.CLOCKWISE)
# left_wheel = Motor(Port.C, Direction.COUNTERCLOCKWISE)
# drivebase = DriveBase(left_wheel, right_wheel, 56, 125)
# left_arm = Motor(Port.A, Direction.CLOCKWISE)
right_arm = Motor(Port.B, Direction.CLOCKWISE)


# The main program starts here.
print('abc')

I have never run into this on the released firmware. Reflashing with https://github.com/pybricks/pybricks-micropython/actions/runs/20963114260#artifacts did not fix it.

I was able to fix it by unplugging and plugging in the motors. However, power cycling the hub doesn't always fix it.

The hardest part is that when doing block coding, it hangs before the user code, so it is hard to know what is going on.

Originally posted by @derrickgw in #2420 (reply in thread)
Originally posted by @laurensvalk in #2420 (reply in thread)

[laurensvalk]

Thank you for analyzing this further @derrickgw !

This is good timing. I think we fixed it this morning. Since you've tried custom versions before, you can try out this one if you like:

pybricks/pybricks-micropython#451 (comment)

We're expecting to merge this to the latest beta version relatively soon.

[laurensvalk]

And now that I read your original point 3 in the referenced discussions again, I see some parallels with: #2385

In other words, there appeared to be some mysterious behavior about programs not wanting to start from the slots, but it could have been this motor issue instead.

This is promising in terms of actually releasing the version with the slots! (with your other points noted too - we may expand it in the future, just starting with 5 for now).