Configure 4 Pins for PWM Output (Analog Voltage) On Maestro

3ddevil

Hi @dc42
If I want to create 4X Analog voltage controllers leaving Fan0 and Heaters 0+1 alone, we have come up with this list, which seems to max out our native controller access:

Fan 1
Fan 2
Heater 2
Servo (Z Bed Probe)

According to the documentation here, it is possible to turn these outputs into controllable PWM outputs using https://duet3d.dozuki.com/Wiki/Gcode#Section_M42_Switch_I_O_pin is that correct?

The heater needs to be disabled and not referenced by a tool "using M307 H# A-1 C-1 D-1 to make the pin available." Is there any such requirement for the fans/servo?

Finally, if buffered correctly (F=10KHz) and routed into a proper RC buffer can we expect to an analog output from 0-3.3V for Servo and 0-Vin for Heater and 0-Fan Voltage Set? Can you confirm this is possible?

are there any more outputs / alternative pins natively supported by the Maestro or is that all we can do with the chip as currently routed?

3ddevil

So this is solved for the Servo output, it worked exactly as expected. Quite amazing!

dc42

@3ddevil said in Configure 4 Pins for PWM Output (Analog Voltage) On Maestro:

The heater needs to be disabled and not referenced by a tool "using M307 H# A-1 C-1 D-1 to make the pin available." Is there any such requirement for the fans/servo?

Yes, see https://duet3d.dozuki.com/Wiki/Using_servos_and_controlling_unused_IO_pins.

Finally, if buffered correctly (F=10KHz) and routed into a proper RC buffer can we expect to an analog output from 0-3.3V for Servo and 0-Vin for Heater and 0-Fan Voltage Set? Can you confirm this is possible?

If using a heater or fan output, you would need to add a pullup resistor to +3.3V if you want a 0 to 3.3V output.

are there any more outputs / alternative pins natively supported by the Maestro or is that all we can do with the chip as currently routed?

The available pins on the Maestro are listed at https://duet3d.dozuki.com/Wiki/Using_servos_and_controlling_unused_IO_pins. Only the heater, fan, and Z probe control/servo pins are PWM-capable.