Turning off servos and M42 interrupting the last pulse

[chrishamm]

@pfn Do you operate the servo from a Duex as well?

[pfn]

@chrishamm no, mine is run off the vfd/laser/out6 port on duet3mini5+

[dc42]

@pfn you can also turn off the servo output using M280 Pnn S0 although you may find that it has the same issue.

[pfn]

@dc42 thanks, my concern is actually how to avoid the truncated last pulse. (For that matter, sending M280 S0 rather than M42 S0 seems to send a 500us pulse as the servo always goes to the 500us position when I use M280 S0)

[dc42]

@pfn which version of RepRapFirmware are you using?

[pfn]

@dc42 3.4.5

[dc42]

@pfn that's odd because I checked the code to confirm what I thought, which is that M208 Pnn S0 should turn the pin off, just like M42. I'll log this as a potential bug.

[pfn]

@dc42 I have this macro: https://github.com/pfn/voron2-rrf-config/blob/master/sys/mmu/lib/engage.g where mmu_servo_engage is set to 0 and it reliably sets the servo position to that of the 500us value.

[dc42]

@pfn said in Turning off servos and M42 interrupting the last pulse:

@dc42 I have this macro: https://github.com/pfn/voron2-rrf-config/blob/master/sys/mmu/lib/engage.g where mmu_servo_engage is set to 0 and it reliably sets the servo position to that of the 500us value.

Do you mean it does that if you uncomment the M42 line and change M42 to M208 ?

[pfn]

@dc42 the macro is just a link to how I have everything setup, if I use M280 P2 S100 and subsequently run M280 P2 S0, the servo 100% reliably goes back to the 500us position.

If I use M280 P2 S100 and subsequently run M42 P2 S0 most of the time the servo stays in place, sometimes it will go to a position between S100 and 500us.

[dc42]

@pfn thanks for the clarification.