What is the easiest way to add an E-stop to the Duet?

I take it the E0 or E1 STP pins do not drive an interrupt, same as the other endstops? Any interrupts on the expansion header? Just use the reset pin on the expansion header? Pull high or low?

Many thanks.

Theo

If you mean an emergency stop button, connecting the reset line to ground is the simplest option. There is a capacitor connected to the reset line, so I suggest a 100 ohm resistor in series with the push button.

Also see [reprap.org] in particular trigger 0. However, the current implementation does not always work instantly. This is due to be fixed (for trigger 0 in particular) in a forthcoming firmware update.

In principle, any of the input pins can be used to generate an interrupt.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

OK, thanks. In the future it would be nice if the endstops were interrupts and any endstop (including E0/E1) could be used as an emergency stop (print stop) without resetting the board.

Just constructive feedback, I appreciate that I'm not paying you for this so don't stress about it. Thanks again!

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Theolodian
OK, thanks. In the future it would be nice if the endstops were interrupts and any endstop (including E0/E1) could be used as an emergency stop (print stop) without resetting the board.

Just constructive feedback, I appreciate that I'm not paying you for this so don't stress about it. Thanks again!

What would you want an emergency stop that doesn't reset the board to do:

- Turn all heaters off?

- Turn all motors off? Or just stop them where they are but leave them energised?

I'm trying to see what can be gained by having an emergency stop that does less than a reset, given that any true emergency stop would make it impossible to restart the print anyway.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

... there are several "stop"-options with software and hardware:

- software - "Normal" Stop in software with Resume possibility - the G-codes in the buffer/queue will be executed before stopping
- software - "Normal" Stop in software without Resume possibility - the G-codes in the buffer/queue will be executed before stopping
- software - "Emergency Stop" per G-code "M112" - all motors and heaters will be shut down instantly ... restart with "M999"
- hardware - "Emergency Stop" - external emergency button, which shuts down the power ... restart when released again ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

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VDX
... there are several "stop"-options with software and hardware:

- software - "Normal" Stop in software with Resume possibility - the G-codes in the buffer/queue will be executed before stopping
- software - "Normal" Stop in software without Resume possibility - the G-codes in the buffer/queue will be executed before stopping
- software - "Emergency Stop" per G-code "M112" - all motors and heaters will be shut down instantly ... restart with "M999"
- hardware - "Emergency Stop" - external emergency button, which shuts down the power ... restart when released again ...

No hardware e stop button I've ever used "restarts when released again" for a good reason, safety. Without exception they require positive intervention to reset the switch physically and require you to acknowledge in the control that you are recovering from an e-stop condition. Sometimes going as far as requiring a reset of the control. The last thing I would ever want is for a machine to begin running again once I took my hand off the e stop switch.
Imo the only place for an e stop switch is a mechanical switch/possibly with contactor that cuts power, I don't like software solutions with the semi exception of purpose programmed Plcs as a safety supervisor.

Edited 1 time(s). Last edit at 07/15/2016 03:42PM by Koko76.

I would like an E-stop that didn't require fiddling around with the USB cable to get the Duet to talk to the PC again as happens after a reset.