--- a/firmware/main.c Fri May 12 15:43:43 2017 +0200 +++ b/firmware/main.c Fri May 12 15:46:46 2017 +0200 @@ -88,7 +88,7 @@ default: // switch off pwm and driver OCR1A = 0; - PORTB &= _BV(0); + PORTB &= ~_BV(0); } }