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The sense output from the op amp connects directly to an ADC input. The output is 1 volt per amp. If sense_a is already connected to ground, you will have to disconnect it.

The hall effect current sensor will work fine too. They do tend to have an offset, but you can calibrate that out in software. Just take a reading when the motor is off and subtract it from the reading when the motor is on. If you do use the hall effect sensor, you could connect it between sense_a and ground so it will only measure the motor current.

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boojumliussnark@lemmy.world ⁨1⁩ ⁨week⁩ ago
Thanks again!

Does this look OK, to your trained eye then? Image

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- cmnybo@discuss.tchncs.de ⁨1⁩ ⁨week⁩ ago
  Yes, that is wired correctly.
  
  Did you get the 5 amp current sensor or the 30? The higher current ones output less voltage per amp, which will make it harder to measure small currents.
  
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  - boojumliussnark@lemmy.world ⁨1⁩ ⁨week⁩ ago
    I got the 30 amp. My thought was that the motor uses up to around 20 watts when running so a little more than 1 amp, and as far as I can tell, it tries to pull around 6-10 amps(!) when stalled/almost stalled. I think this should mean a fairly large spike, that I should be able to detect even with the 30A device.
    
    But of course it is probably just absurd overkill, and will make my life more complicated. Fortunately they are absurdly cheap and easy to buy, so if the resolution turns out to be a problem, I can get another range, when I have some empirical data. The other ranges should plug in, in the same place right?
    
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    cmnybo@discuss.tchncs.de ⁨1⁩ ⁨week⁩ ago
    The other ranges connect exactly the same.
    
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