M43 - Debug Pins

debug Get information about pins. PINS_DEBUGGING

When setting up or debugging a machine it’s useful to know how pins are assigned to functions by the firmware, and to be able to find pins for use with new functions. M43 provides these tools. M43 by itself reports all pin assignments. Use P to specify a single pin. Use W to watch the specified pin, or all pins. Use the E option to monitor endstops.

The W watch mode option continues looping, blocking all further commands, until the board is reset. If EMERGENCY_PARSER is enabled, M108 may also be used to exit the watch loop without needing to reset the board.


M43 [E<bool>] [P<pin>] [W<bool>]

Argument Description

Watch endstops


Digital Pin Number


Watch pins


Requires PINS_DEBUGGING. This feature should be disabled for production use.


Get a report on all pins


Watch pin 56 for changes

M43 P56 W

Start watching endstops

M43 E