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AS5047 with VESC75/300

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Mon, 2021-11-29 10:11
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hpb66
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AS5047 with VESC75/300

Hi all,

I intend to connect an AS5047 encoder to my VESC 75/300. The baseline connection is clear to me, however, I have some questions (don't want to risk to burn my VESC):

- is it mandatory, to swap the resistors R1 and R2, if I want to connect it with my VESC? I found a description, where it is stated, that for the 3.3V operation voltage, the VESC has, R2 has to be populated and R1 has to be removed on the AS5047 pcb. Is this really mandatory or only optional for higher accuracy?

- do I have to remove physical filters on my VESC 75/300 as well? Does this mean, to open the unit and solder some physical, likely very small parts, out?

Or is there an easier way, to get good control at zero speed in current control mode?

Thanks!

HP

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Mon, 2021-11-29 13:27
frank
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3.3V operation is best. 5V is a bit noisy. Set VESC sensor voltage to 3.3V via the small internal switch and solder R1 into position R2.

https://trampaboards.com/resources/manuals/207.pdf

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Mon, 2021-11-29 13:53
(Reply to #2)
hpb66
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Thanks for clarification. So I need a quiet hand to do the soldering. In the document, I see, that the R1 is a 0Ohm resistor. So could I also replace this one by a soldered bridge only (just in case)?

And another question: is there a difference in the two sheets of the referred document? Can't find a difference ......

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Mon, 2021-11-29 17:50
frank
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It is a Ohm and you can bridge it with solder. The manual displays twice for some reason.

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Thu, 2021-12-23 14:13
(Reply to #4)
hpb66
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Finally, I received my cables and connectors and wired the unit according your manual. What do I have to change in my VESC-tool in order to activate the AS5047?

 

 

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Fri, 2022-01-28 20:17
canoeman
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Hoping you've got this sorted but if not:

  1. Motor Settings > General > General > Sensor Port Mode: Set to "AS5047 Encoder"
  2. Motor Settings > FOC > General > Sensor Mode: Set to "Encoder"
  3. Motor Settings > FOC > Encoder > Sensorless ERPM: Set to some sensible value like 3000. Experiment with this later and set it as low as you can get away with.
  4. Motor Settings > FOC > Encoder: Run the "Detect Encoder" setup at the bottom of the screen. Amperage around 20A tends to work for the size of motors folks run with the VESC75/300, but you may need more. The way to tell is by running the detection repeatedly. If the "Offset" value changes by more than a degree between runs, increase by 10A and try a few more times. Once your detection offset is stable between runs, apply the results and write motor configuration.
  5. Your motor should now be capable of really smooth torque at low RPMS

I really like using an absolute sensor on a the VESC and would hope that this catches on increasingly for applications like robotics, cnc machines, high power servos, human interface systems, etc. If the AS5047 gives you trouble, you can also go with the CUI AMT 31 series and configure it to emulate UVW hall sensor signals but with much lower noise. I've had good luck with both.

 

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