Hello RepRapMakers.
I would like to cool and to heat the nozzle, using peltier cells or similar electronics.
Is there a way to select whether to cool or heat?
For example, if I have want to cool, I will connect the peltier as indicated (red to Vcc and black to GND); but if I have to heat it has to change the polarity (red to GND and black to Vcc). And for that, I would like Marlin to indicate the polarity with a pin. It's possible?
Thank you very much!