For proper PULSE out operation a small mod is required:

1) cut a trace between PIN8 and PIN9 of IC9 (on the bottom / components side)

2) solder 20K resistor across these pins (0603 SMT will work perfectly)

3) solder 10K resistor across PIN9 and PIN12 of IC9

these 2 resistors are easier to put on the front side of the pcb (not the components side)

4) replace R48 with 10K resistor (if used BOM REV2.0-2.2)

5) replace R49 with 120K resistor (if used BOM REV2.0-2.2)

 

DOWNLOADS:

FIRMWARE REV2.0
BOM REV2.3