FETboard rev3


Now when these are getting into the hands of more and more people, it might be a good idea for me to actually write a bit on how to use it…


On the far right side there is the 2×5 pin header for connecting it to the ramps AUX-2 port. These pins must be soldered on so they point down to connect with the ramps port correctly.

The IN, D44, D59, D66 and D64 I recommend soldering so they point up for easier access.

2012-11-22 00.43.49 (Large)

The IN pins connect to the power supply directly to bypass the arduino and protect it from getting overloaded.


Each of the other pins can then be turned on with M42 or one of the automated functions already in the firmware for turning the pin on/off depending on hotend temperature and stepper driver status.

When connected to ramps the D44 even got PWM capability due to the ArduinoMEGA having pwm on D44-D45.


The mosfets on the board can handle 20A on one channel, but I only recommend a total draw of 3A on all pins. Meaning you can do 4x 750mA, 2x 500mA + 1x 2A, 1x 3A, 3x 1A, or what else you could fancy, as long as the total is 3A or less.


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