BLE Pairing mode crashes on mbed.org based builds

[finneyj]

micro:bit appears to hard fault when a BLE pairing attempt is requested... But behaves correctly for offline builds based on yotta / gcc.

[ghost]

It does indeed. Very easy to reproduce. Happens for all possible values of MICROBIT_BLE_SECURITY_LEVEL as well.

If you reduce MICROBIT_NESTED_HEAP_SIZE to 0.50 the problem no longer occurs, albeit at a cost. I guess recent changes have pushed memory use over some threshold?

So, needs some optimisation somewhere or else it needs MICROBIT_NESTED_HEAP_SIZE to have a new default value.

[ghost]

See https://developer.mbed.org/users/bluetooth_mdw/code/microbit-pairing-test/