[Bug] Strange poweroff issue on City Hub with one motor and remote

[laurensvalk]

This seems to be different from #692 or #385 .

Describe the bug
In specific circumstances, the hub does not turn back on until you pull the battery.

To reproduce (preparation)

• Install CI build v4.0.0b7 on City Hub
• Create a program called Poppen.py with the code given below.
• Connect a motor to port A.
• Run the program normally
• Shut the hub down.

To reproduce

• Turn the hub on, run the program
• let it find the remote, press some buttons to turn the motor
• turn the he hub off
• this seems to be critical release the button as soon as the blink begins

Now the hub appears off but it is not. You cannot turn it back on with the button. If you long press, you immediately go to the shutoff animation again. It is unclear to me that this means it enters shutdown again, or made a full boot cycle and got stuck a second time. (And any firmware change like debugging makes the issue go away)

You have to pull the battery, then attempt to turn it on, and only then reinsert the battery. Then you can turn it on again.

This seems to happen consistently once you get the pattern right. But this happens only with this particular build and with this particular program. It does not happen when I build the firmware locally and it does not happen if I change the motor and program to use port B.

# long comment
from pybricks.parameters import Button, Color, Direction, Port, Stop
from pybricks.pupdevices import Motor, Remote
from pybricks.tools import wait

# Set up.
remote = Remote(timeout=None)
motor = Motor(Port.A, Direction.CLOCKWISE)
Color.BENEDEN = Color(202, 100, 100)
Color.BOVEN = Color(0, 100, 100)
Color.STOP = Color(320, 100, 100)


# The main program starts here.
while True:
    if Button.RIGHT_MINUS in remote.buttons.pressed():
        motor.run(300)
        remote.light.on(Color.BENEDEN)
    elif Button.RIGHT_PLUS in remote.buttons.pressed():
        remote.light.on(Color.BOVEN)
        motor.run(-300)
    else:
        remote.light.on(Color.STOP)
        motor.stop()
    wait(10)

[BertLindeman]

To reproduce

Turn the hub on, run the program

I assume you did F5 or button-click to run the program.
Did you try to start with the hub button?
Difference is on F5 the new compile and on button-press start that step is missing.

[BertLindeman]

Strange:
Tried the program on the firmware that happened to be on the cityhub (No idea..)
Did not recreate, BUT
install of b7 started OK but then message "waited too long" or something like that
(Have to say the motor was still connected)

Now I cannot start the hub using the button.
Over 10 seconds press and keep the hub button - no reaction.

• motor disconnected
• battery out
• press hub button for 5 seconds
• battery in
• long press goes into update mode (and I do not need to keep the button pressed)
• fimware install OK V4.0.0.b7
• could not recreate this issue
• will do a few times and report back.

[EDIT]
After 10 attempts no success to reproduce.

[BertLindeman]

Bingo.... after many tries

On power-off the blinking seems longer (after I no longer kept the button pressed)
Did not need to do anything with the remote.
I just:

• press the hub button to start the program
• long press the hub button and gamble when it would go into power-off.
• short press the hub button
• no power-on
• 10 seconds press of hub button : nothing happens also NOT the firmware install violet.
• battery out
• press hub button for 5 seconds to drain all power
• battery in
• short press - blue blink "ready to run"

[BertLindeman]

Tried 80 times the scenario in the post before this one.

• hub button to:
  • power-on
  • start the program
  • long press and attempt to release the button on first power-off blink

But no hit using V4.0.0.b7.