End stops / Homing / safety

1

Hi all

I am building a pick and place using O drive and I need to implement at the very least end stops on the ends of travel to avoid the obvious driving into end stops at speed.
Is the branch at https://github.com/Wetmelon/ODrive/tree/Endstops the way other people have gone ?

I am considering two types of home.
I) One for home … Opto switches
ii) One for emergency endstop … Cut the power and introduce a brake resistor across the windings separate to the odrive board.

I have seen a video somewhere but can’t find it for the clearpath servos using a bump stop to home against.
Driving into it at a low power and using one of its readbacks (current / speed maybe).

I know there are a couple of threads on here about this but they are pretty old .

I would appreciate other users ideas / experience ?

Peter

2

My Endstops branch uses the “minimum” endstop as a homing switch at startup, then drives off the endstop slightly and enables both “minimum” and “maximum” as E-stops, so if they’re pressed after initialization the machine will free-wheel and throw an Axis error. Sounds like what you want :slight_smile:

Also, I just updated it to the most recent Devel branch very recently so it’s ready for testing.

3

Thanks
I will take a look at the code tomorrow.
I assume the io mapping is defined in an obvious file.

It sounds ideal thanks for sharing.

Peter

4

Hi Paul (wetmelon)

I found one of the previous threads explaining how you config.
Very nice that’s its done via software.

Peter