L'Hexapod: Sensing servo torque

Previously published

This article was previously published on lhexapod.com as part of my journey of discovery into robotics and embedded assembly programming. A full index of these articles can be found here.

Whilst playing around with my servo controller I realised that the power used by a servo goes up considerably when it’s under heavy load (such as when it’s pressing against the table and still trying to move). I can, potentially, get an idea of this load by measuring the current that each servo is using and using this feedback somehow. I’ve yet to work out how, but at the very least it could be used to protect the servos against overloading; if the load gets above a certain threshold then stop moving! Ideally the servo controller could feed this information back to the user of the servo controller as well. Anyway, this requires quite a large amount of breadboarding changes, the use of some active low multiplexor chips and some playing around with the ADC on the ATMega. I don’t think I’ll experiment with this just yet…