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Emergency stop --> external button

Posted by Arnix 
Emergency stop --> external button
November 27, 2018 05:08AM
Am planning to add two external button switches.

Something like this:

One for emergency stop, and one for G28 command and continuing with program execution ( reset with vision program auto start ).
At the moment PC ---> Duet comm is done over USB cable.

What would be "best" way to read this impulse and pass it to running program ?
Arduino --> serial2USB converter --> reading data from this USB device and passing in realtime to vision program ?

btw. what command should be executed for emergency stop ?

Re: Emergency stop --> external button
November 27, 2018 09:04AM
I'm using a reset button as a kind of emergency stop. It's tied to GND and Duet's reset pin, so the controller resets when you press it. This effectively also cuts power to the motors, heaters and fans because PS_ON defaults to off, making the power supply turn off the higher voltage. I also have a big switch that cuts all power to the power supply in case stuff goes seriously awry.
Re: Emergency stop --> external button
November 27, 2018 09:40AM
OK. Thnx for input. I will add this to list of options :-)

Basically, one option should be used for "small" errors and second for power cut off.
In end effect i want to make this user friendly as much as possible. This is why i was planning
to reset the vision program after some small error acours.
E.g. G28 + trigger on some python script which will reset vision system.
In this case reset would be over in 3- 4 seconds... just an idea.

I guess that something similar can be done with your setup.
Hmm, i would need some kind of confirmation that G28 / homing was executed correctly,
before i can trigger restart of vision system...This could be a problem.....

Re: Emergency stop --> external button
November 28, 2018 02:04AM
Your vision system could add a request_pin_state after each move. That way a switch ( no push button ) can cause a pause (or maybe run a macro of your liking?).

In RRF it could be M577 or similar ( eg. filament runout sensor )
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