micro:bit v2 does not run CircuitPython code

[colinvail6]

CircuitPython version and board name

Adafruit CircuitPython 10.0.3; micro:bit v2 with nRF52833

Code/REPL

import time
import digitalio
import board

led = digitalio.DigitalInOut(board.LED)
led.direction = digitalio.Direction.OUTPUT
while True:
    led.value = True
    time.sleep(0.1)
    led.value = False
    time.sleep(0.1)

Behavior

Serial console setup

Auto-reload is off.
Running in safe mode! Not running saved code.

You are in safe mode because:
CircuitPython core code crashed hard. Whoops!
Hard fault: memory access or instruction error.
Please file an issue with your program at github.com/adafruit/circuitpython/issues.
Press reset to exit safe mode.


Adafruit CircuitPython 10.0.3 on 2025-10-17; micro:bit v2 with nRF52833
>>>

Description

micro:bit v2 crashes due to out of bounds memory access

Additional information

When clicking 'run current script' in Thonny it causes the memory error

[dhalbert]

This may be just a Thonny-related problem. Thonny runs a lot of stuff invisibly in the REPL. There is a possibly related issue here: #8364. Try a different editor. #8038 is also possibly another manifestation of the same thing.

This is not Thonny's error, but an uncaught exception in raw or paste mode, which Thonny uses, does not seem to be handled properly and causes crashes.

[dhalbert]

@colinvail6 I think this problem will be fixed by #10805. However, note that there is no board.LED on a micro:bit, so your original problem will still fail, but in a better way, without a hard crash.