Controlling BLDC board via DuetWIFI PWM signal

  • I am using a 3 phase CPAP blower as my parts cooler on my printer. Right now, I'm using a DC-DC relay to turn it on or off via the fan plug on the duet board. This works great to just turn the fan on/off, but the only way to actually adjust the airflow is via the pot on the BLDC board.
    I ordered a new BLDC controller that has the ability to be controlled via PWM and was wondering what pin I can use on the Duet Wifi2 board to control it. I've read on other threads that you can use the fan ground pin? On the BLDC purchase page it says:

    Speed control signal input (integrated potentiometer for speed control on the board can also be connected to 0-5V analog quantity to support PWM to 0-5 signal input speed control)

    Thanks for your help

  • i think someone posted that board before, not sure how it turned out, but if it works like other bldc esc's then you configure it as a servo.

    however as you want to use it as a cooler you'd be better off configuring it as a fan and experiment with the frequency and duty cycle to see if you could mimic the servo signal using a fan config (but the resolution of your control will suffer). there is a thread on using a fan to mimic servo signals with a more in depth on the limitations.

    all output pins on the duet2wifi are pwm capable to be configured as heaters, fans or servos.

    but to give a definitive answer more specs on the control input signal of the module is needed. you may also have to get the signal up to 5v from the 3.3v the duet operates at (a (inverted?) fan/heater output and a 5v pull up maybe?)

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