AMT21 RS485 Encoder

Support ODrive Pro Support
1

Does ODrive Pro support the multiturn AMT21 Encoders? i.e the AMT21xC or AMT21xD

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2

Hi,

It’s supported, but the multi-turn feature itself isn’t supported, it will behave the same as if it’s a single turn variant. The ODrive keeps track of the turn count by itself though, so should work well either way.

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3

Hello Oscar,
Related to your reply on lli’s question, where can i find detailed documentation on the S1 controller?
I am trying to figure out if the on-board absolute magnetic encoder is single or multi-turn and does it save the multi-turn variable after reboot?
To give more context, in my setup i have 1:5 gear ratio between motor and large capstan and i need to find the motor angle that correspond to my outer capstan 0 position (mechanical limit) so to avoid homing at every reboot,
Due to the relatively large gear ratio, the workspace at the output capstan correspond to more than 1 turn at the motor level, so i need this piece of information,

Thank you,

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4

Hi,

The on-board encoder is multi-turn, but there is currently no storage of turn count in non-volatile memory, so the turn-count is unknown after a reboot.

There are a few ways to handle this.

  • Supply the turn count (approximate location) after boot, see details here.
  • Supply standby power to the ODrive so it can keep track of the encoder position even though main motor power is turned off. Supply 12V on pin 5 on the main connector with respect to DC-, see details here
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