Duet 3 Mini 5+ and Servo Setup

hugocross

I have looked around and am finding conflicting information on how to properly wire a 5V servo on a Duet 3 Mini 5+ board.

A breakdown of my current OUT wiring:
OUT3 - Part Cooling Fan 1
OUT4 - Part Cooling Fan 2
OUT5 - Hotend Cooling Fan
OUT6 - Mainboard Cooling Fan

I have a 5V servo motor that I am trying to use for filament cutting. I am powering it off an external 5V line from a BUCK converter off the main Meanwell PSU due to the documentation stating that it can have feedback issues with the PanelDue. So I guess my main questions based on what I was reading online are the following:

Do I need to use an OUT for the signal line and GND? Some of the articles explaining this all referenced using them and I do not want to buy an expansion just for this one servo.
Many of the posts I saw stated I could use a GPIO PIN in the SBC port for the Signal, but where would the GND connect (also the GPIO 6,9,14,20,25?)
How are the GPIO pins in the SBC port numbered? I know it is a 0-25 configuration, but which end is the 0? Closer to the EXP1 or the IO_0?

Also I could be seriously overthinking this whole thing. Please feel free to ask more questions so I can better understand this.

droftarts

@hugocross see https://docs.duet3d.com/en/User_manual/Connecting_hardware/Motors_servos

Duet 3 Mini 5+: There is a dedicated 5V PWM header, which provides 5V signalling, shared with OUT_6. Otherwise use any PWM-capable IO[n].out pin for 3.3V signalling. See Duet 3 Mini 5+ Hardware Overview. Headers on CAN-connected expansion boards can also be used.

If all OUT headers are used, use an IO header. io3, 4 and 5 are PWM capable. See https://docs.duet3d.com/Duet3D_hardware/Duet_3_family/Duet_3_Mini_5+_Hardware_Overview#io-headers

Ian

hugocross

@droftarts So since I have the 5V line for the servo hooked externally and the GND wire would go to the GND Pin on IO_3, would I use the 3.3V for signaling? Just triple checking.

hugocross

Oh wait I read that wrong. "Otherwise use any PWM-capable IO[n].out pin for 3.3V signalling." I am blind lol.