Rumba - EXP3 Pins spinning smiley sticking its tongue out
February 26, 2017 09:20AM
Hello everyone !

I'm trying to connect a 5V relay to control a 220V fan when a print is finished.
There is no 5V fan connector on the rumba board and I wanted to remap the unused EXP3 connector to power my relay with the gcode fan command.

But I don't now how, and I've never touched the Pins.h file.

Can you help me ?

Thanks a lot,

A.P
Re: Rumba - EXP3 Pins spinning smiley sticking its tongue out
February 26, 2017 09:40AM
On EXP3 there is PWM_1 located, which is defined in my Rumba_pins.h as Servo pin ( meaning it is already defined as output ) The CPU-pin# is "1"
So in theory you could send a gcode "M42 P1 S255" to switch the relais. BUT this pin is directly connected to the CPU and not very powerful. I doubt it can drive a relais.
It would be easier to use a MOSFET driven fan-output and split the output voltage with a resistor divider.
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