I have a bldc motor control board(ESC) with potentiometer, the pot is used for controlling speed but I want to use arduino's pwm, so how to remove the pot and replace it with arduino connections?

The board has dual-pot connection for bidirectional speed control and I bought this online, I don't have schematic.

Motor specs: 36v 9amps bldc

esc specs: 36v 15amps

enter image description here

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    \$\begingroup\$ You haven't told us what this board does, what your motor is, what the specs are, or what you want it to do. Realistically, an Arduino isn't made to handle power so you'll need a board like this anyway to drive a motor of any real size. \$\endgroup\$ – vir Feb 22 at 17:20
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    \$\begingroup\$ I'll go out on a limb here and say "you can't". Depending on what kind of current runs through that pot, a programmable resistor isn't going to work without so much circuitry as to be an entirely new motor controller anyway. Just buy one of the Arduino shields that is also a motor controller. \$\endgroup\$ – Ron Beyer Feb 22 at 17:20
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    \$\begingroup\$ In theory if you don't need fast changing signals, you can use the Arduino to output a PWM, and then low pass filter it, to create a DC level and then inject that to where the wiper terminal connects. However, your picture shows 5 wires to the pot, so you'd need to show a schematic for us to go much further. \$\endgroup\$ – Aaron Feb 22 at 17:23
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    \$\begingroup\$ We do need more details than pictures of a board have you got a schematic? \$\endgroup\$ – Wintermute Feb 22 at 17:27
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    \$\begingroup\$ @PeterBennett Almost certainly a pot with a switch at full CCW rotation, and the rocker switch is most likely a direction switch regardless of how it is (mis)labeled. If there's 5V across red and black on the 3-pin pot connector then it's easy. But zero isolation components on that AC motor speed control so a momentary error could take out the board, the Arduino and whatever computer might be plugged into the Arduino. \$\endgroup\$ – Spehro Pefhany Feb 22 at 18:18

I would expect something like this. I assume the green wire header ABC V+,0V are the 3 phase Hall Sensor inputs.


simulate this circuit – Schematic created using CircuitLab

Power Off switch at full CCW and Power ON at low Speed only.

FWIW I am doing a similar project this winter to my 100W 3phase BLDC attic Fan which will be controlled by a wireless digital thermostat alarm voltage, but I could also do speed control to pot voltage in parallel with mid-scale setting.

I suggest you measure it to verify the details.


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