I just stumbled across the fact, that Smoothie currently doesn't support an emergency stop - so it's difficult to use this board for more complex projects than just hobby machines where you don't have to care about safety so much.
Currently you can send the M84 command to turn off power supply to the motors, but that command only does get executed at the end of a current move - which might be way to late. So I'd like to see Smoothie to support an immediate emergency stop for the whole machine, so breaking all the motors and setting all outputs to a defined (safe) state.
Realisation of this feature could be done with following steps:
Step 1: Basic Support
- Switch of power supply to motors immediately
Step 2: Enhanced Basic Support
- additionally set outputs (mosfets) to configurable defined states (heating off, breaks on, …)
Step 3: Full Suppport
- leave power supply to motors on, and decelerate with maximum possible deceleration
- maybe (configurable) switch off power supply to motors now
Enabling Emergency Stop function would use one/two microcontroller input pins.
It would be nice if it would also be possible to enable Emergency Stop with a G-Code, if it's possible and would meet time requirements.
Thanks's in advance