v1.1 tool board extruder + filament sensor?

kb58

This was asked by someone but it wasn't answered, and I have the same question. If a v1.1 tool board is controlling an extruder, must the filament sensor also be connected to the tool board, or does it not matter and it can be connected to the 6HC board?

Alex.cr

@kb58
The filament sensor must be connected to whatever board has the extruder connected. In you case I would assume your toolboard controls your extruder. So yes, this would be required.

It would be super convenient if this was not a limitation but its understandable. I believe @dc42 has stated in the past that this is required due to pulse timing and checking in the firmware.

The only way around this is if you are using just a regular filament runout switch. You could configure it as trigger and have it run pause.g or any other macro.

kb58

@alex-cr Thanks. The filament sensor is IR, but the output is just a logic level, so maybe it could be used on other boards. I think in this case, though, I'll place it above the extruder and run it to the tool board.

Phaedrux

https://duet3d.dozuki.com/Wiki/Duet_3_firmware_configuration_limitations

Filament monitors must be connected to the same board as the corresponding extruder motor. This use so that the firmware can correlate the measured filament movement and the commanded extruder movement in real time.

What kind of filament sensor is it? Does it track filament motion, or is it just a simple presence detection?

kb58

@phaedrux It's just a simple (probably open collector) IR sensor that is interrupted by the material. A long way of saying, yes, just a simple presence detector. For that reason, I suspect I could just treat it as a switch on the main board, but still haven't decided where it fits best.

Phaedrux

Yes if it's just a simple switch then the previously mentioned limitation doesn't really apply. It's just an endstop.

dc42

@kb58 currently any filament monitor or sensor configured using M591 must be attached to the same board as the extruder motor. We may make an exception in future firmware versions for simple filament presence detectors.

kb58

@dc42 Okay, thanks, question answered!

dc42

@kb58 you can connect it to the main board if instead of configuring it via M591 you configure it as a GpIn pin and set up a M581 trigger on it.