I am looking to ODrive data since several days and cannot find any tips to make “homing” sequence using an absolut SPI multiturn encoder (like an AMT21) or a multi-turn potentiometer (like 10 turns burns).
My intent is to have 2 motors going to 0 position at startup even if motors have turned more than 360° from the 0 position during power off.
Is it a way we can manage this “homing” from multiturn offset position using ODrive?
I am currently open to any advises in order to set my configuration.
If SPI multiturn encoder are tricky to setup I can move to 10 turns potentiometer or other solution that can fit my needs.
Thanks a lot in advance for your great help!
Cheers,
Fabrice
Amt21 and other cheapcmultiturn encoders don’t store the turn count when the power is off. The counter only tracks the number of turns when it’s on. It’s essentially single turn+turn counter instead of a true multiturn. True multiturns are usually much more expensive.
It is what i thought.
I am now wondering if it will be possible to couple a classic incremental encoder to a geared potentiometer linked to motor shaft to make the homing.
Here an example using a motor that as made 20,7 turns from home position during power off.
If I use a setup coupling an incremental encoder and a geared potentiometer linked to the motor shaft, I was thinking to read the potentiometer value at power-up (using Odrive GPIO) and determine that the motor is 20,7 turns far from home position. From this point, I was thinking to request a self calibration.
When calibration done, the potentiometer should indicate that the motor is at 20 or 21 turns from the home position. So then, I will request the motor move 20 or 21 turns go to home position?
If you just want to home it anyway, use a single turn absolute encoder and a normal velocity-based homing. Multi turn encoders are for when you can’t use homing