PIR driving TIP120 goes high when the TIP120 is powered

[johnerrington]

@kingbombo

The transmitting nano is also using a PWM to step up a TIP120 MOSFET that powers an 8W, 12v/1a LED illuminator.

The TIP120 is NOT a mosfet.

file:///C:/Users/johnl/AppData/Local/Temp/TIP120-D.PDF

Your schematic (I love greenshot!) shows R1 connected to D7 - so why

@kingbombo

int LEDout = 12;

also the cap across base & emitter makes no sense.