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VESC 75/300 with sin/cos encoder

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sajjen
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VESC 75/300 with sin/cos encoder

I have a boat with a Heinzmann PMS 120 motor, powered by a 16S LiFePO4 pack and controlled by a Sevcon Gen4 controller.

I'm considering a switch to the VESC 75/300. The VESC Tool seems like a much more useful tool then the Sevcon software.

The motor is equipped with a sin/cos encoder. Would the VESC be able to interface this?

frank
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It would be good to find out the exact encoder. Since the code is open, it is possible to change the code to make it work. You could also try and use a AS5047P magnetic encoder instead of the motor encoder.

sajjen
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I'll try to find a spec on the sensor.

The output is two analog signals. After digging through the code for the VESC firmware, it seems that there is indeed support for sin/cos sensors. There are however not two spare analog inputs available. Perhaps it would be possible to reconfigure the analog throttle input pins to be used for the sensor?

frank
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I'll ask Vedder on Thursday.

marcos_
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The code support is there, but requires some special hardware as you don't want your unprotected ADC traces going near the motor.

All working sin/cos implementations I've seen have a differential sin+/sin- and cos+/cos- signaling to reject common mode noise, protect the MCU ports and enhance the encoder accuracy, because a few mVolts of noise there cause large angle errors, and if the low pass filtering is too strong it introduces delays in the measured angle at high-ish speeds.