Duet3 Endstops unresponsive

plasticfactory

Hello, first time Duet user here wiring up a Duet3 for an Ender3 Pro. I am using the stock Creality switches.

I have V wired to 3.3, and S to Io0.in for the X axis. Voltages and continuity appear fine when checking with a meter. The corresponding steppers appear to function correctly (hard to say as they don't like to behave when I can't properly home the machine, but they have the ability to move in either direction and lock).

Relevant code:
M574 X1 S1 P"io0.in"

Simply put, the endstops do not seem to trigger. The endstop status provided by M119 seems only to respond to whatever config setting exists. Manually triggering the endstops does nothing. It appears that something is wrong with the board to me, but with everything else functioning correctly I'm far from ruling out user error.

I'm at a complete loss here and obviously can't move forward without resolving the endstop issue. Any assistance or troubleshooting ideas are very much appreciated.

Nick

plasticfactory

Hardware and software information:
Board: Duet 3 MB6HC (MB6HC)
DSF Version: 1.1.0.5
Firmware: RepRapFirmware for Duet 3 MB6HC v0.6 or 1.0 3.0RC2 (2019-12-29b1)

A Former User

@plasticfactory said in Duet3 Endstops unresponsive:

I have V wired to 3.3, and S to Io0.in for the X axis

V and S? Presumably this is the two sides of a mechanical switch? If so try ground and Io0.in instead.

blt3dp

If I recall correctly, io0 was reserved for PanelDue. I’d move the endstop from that one. You might also try inverting the pin by throwing an ! In front of it, or turning on the pull-up resistor by putting ^ in front. Or any combination thereof.

plasticfactory

@bearer Correct, both sides of the switch.

Moving 3.3v to GND at the board seemed to work (I'm running out the door and only tested by a quick click and check on the machine control panel, no M119).

Could you provide a little more information on why this works? I wouldn't have thought to do it.

A Former User

@plasticfactory said in Duet3 Endstops unresponsive:

Could you provide a little more information on why this works? I wouldn't have thought to do it.

with the risk of sounding a bit harsh, because RTM.

on the technical note its common practice to pull inputs low to assert them, it saves you from dealing with mixed voltages.

A Former User

@blt3dp said in Duet3 Endstops unresponsive:

or turning on the pull-up resistor by putting ^ in front.

if the switch is connected between positive and the input, you'll need a pull-down resistor or the signal will always be high or floating.

plasticfactory

@bearer No worries, I was hesitant to post for this reason. I have honestly read so much documentation I have no idea where I missed this, but I'll put more effort into my due diligence next time.

Thanks for the explanation, and help, again.

A Former User

this was the link i should have posted, but was on a slooooow link before: https://duet3d.dozuki.com/Wiki/Connecting_endstop_switches#Section_Microswitch

has pretty detailed info on endstops

Phaedrux

@plasticfactory said in Duet3 Endstops unresponsive:

I have honestly read so much documentation I have no idea where I missed this

We're always here as a sanity check.