Duet 0.8.5 GPIO Pins For Heaters

ElmoC

I have been searching around looking for a mapping of which GPIO pin is controlled by which heater. Specifically, I am wanting to use these extra outputs for servo control but not sure which pins to use. The GPIO on the DuetWiFi has them marked, so that's easy. Now I just need to find which pins on the 0.8.5 board are for the heaters.

dc42

Does the schematic at https://github.com/T3P3/Duet/blob/master/Duet0.8.5/Duet0.8.5_Schematic.pdf help?

ElmoC

Not really. I had been looking at that before. I see several pins on the GPIO with PWM on them, but don't know which one goes to which heater. So on the 0.8.5 board, if I use M280 P5 S100, which pin does that come out on?

I did have a question on the GPIO pins on there. Both pin 19 and 20 are marked as PWMH2 (PB14/PWMH2 and PC7_PWMH2). Is the PWM mislabeled on one of them?

dc42

I doubt that the PWM is mislabeled, because the same PWM output can be configured in the microcontroller to appear on more than one pin.

Page 3 of the DueX4 schematic at https://github.com/T3P3/Duet/blob/master/Duet_Expansion/Duex4v0.2a/Duetx4_v2a_Schematic.pdf shows how the expansion connector pins 18 and 21-23 correspond to heater PWM pins.

ElmoC

@dc42:

I doubt that the PWM is mislabeled, because the same PWM output can be configured in the microcontroller to appear on more than one pin.

Page 3 of the DueX4 schematic at https://github.com/T3P3/Duet/blob/master/Duet_Expansion/Duex4v0.2a/Duetx4_v2a_Schematic.pdf shows how the expansion connector pins 18 and 21-23 correspond to heater PWM pins.

Thanks. I added a table to the reprap gcode wiki for M280 with the mapping.

ElmoC

I verified control of pins 21, 22, 23 as heater 3, 4, and 5. I have not been able to determine what number to use to control pin 18. Based on the label, I would guess heater 2, but that didn't work.

dc42

Pin 18 would be heater 2 if you are using a Duet 0.6 and heater 6 if using a Duet 085 (because the heater 2 mosfet is on the Duet 085 itself). However, heater 6 and fan1 share a pin on the 085, so you would have to disable fan1 to use heater6. It's easier to use fan1 instead.

ElmoC

Thanks. Will make note of that.

lazy_mosquito

Which heater or fan connector do i use on the 0.85 board itself? i have no expansion board, but want also control a servo.

M280 P?

which parameter should P get and to which connector should i connect the signal pin of my servo?
i have 5V from my ATX powersupply which has common ground with my duet 0.85 board

Pieter

lazy_mosquito

Found it out for duet 0.85

connected servo signal to pin 21 (pc23) of the extension header.
red and ground to 5v signal of external ATX power supply (same power supply is used for powering the duet, so common ground)

in code (config.g)
M307 H3 A-1 C-1 D-1 is added to reserve pin 21 for M42 or servo use

Deployprobe.g macro contains the line M280 P3 S10 I1 to deploy servo (S10 is 10 degrees and I1 is to reverse polarity of servo)
Retractprobe.g macro contains the line M280 P3 S90 I1 to retract servo (S90 is 90 degrees)
Deploy and Retract macros are added to bed.g and homing macros

thanks to W3DRK: https://www.duet3d.com/forum/thread.php?id=459