Crashing Espruino Pico

Ahh, I think you might have hit the 'console on Serial1' issue. Basically when you disconnect from USB the console moves onto Serial1 (which is pins B6 and B7) by default - and you're using B7.

So you have two options:

• Add USB.setConsole(1) right at the top of onInit, which should force the console onto USB forever, so it never messes with your pins.
  
• Move B7 to some other pin
  
  

I reckon that should sort it out.