Set audio pin creates a 44.2kHz 50% PWM after audio playback

[fabianhugo]

Describe the bug When using the set audio pin block in the pins category or the uBit.audio.setPin(uBit.io.P0); function in microbit-v2-samples and then playing any sounds, e.g. uBit.audio.soundExpressions.play("giggle"); leaves a 44.2kHz PWM signal with a duty cycle of 50% on the previously set pin. . This causes some speakers to heat up, and could therefore lead to broken speakers or other damage.

To Reproduce (makecode)

1. Create makecode project use the set audio pin block in the pins category, choose P0
2. Use the play giggle unitl done
3. Transfer program
4. Probe pin P0

To Reproduce (microbit-samples-v2)

1. Insert the following code to main.cpp: uBit.audio.setPin(uBit.io.P0); uBit.audio.soundExpressions.play("giggle");
2. Transfer program
3. Probe pin P0

[jaustin]

Related https://github.com/microsoft/pxt-microbit/issues/3883 - you can use the setSilenceLevel API in C++ or Typescript. @fabianhugo do you have any more info about the speakers that 'heat up' please? CC @finneyj

[fabianhugo]

Thanks a lot for your swift reply and for pointing towards the other issue. music.setSilenceLevel(0) solved it :)
The speaker that heated up is the speaker from the dFRobots Boson Kit driven by a MOSFET. Can be closed. Thanks!