Disabling dual mc33926 motor driver shield by using gpio for vdd

Support Motor controllers/drivers and motors
1

Hi, the dual mc33926 motor driver carrier provides the EN pin but the dual shield does not. I would like to put the (a*star) arduino I’m using to sleep and also the shield. I see 2 options:

  1. Find out how to access the EN pin on the circuit - I will have to look at the PCB and maybe “invade” it.
  2. Disconnect the VDD to (Arduino) 5V connection and provide VDD via an Arduino GPIO pin.

What do you think about the 2 options? On the last one do you think it is ok to have motor vin connected to 2s lipo battery while vdd is pulled low? I read the datasheet of the mc33926 and it draws 20mA in normal operation and 40 mA is typically ok for an arduino to provide via a GPIO.

Greetings from Heidelberg, Marcus

2

Hello, Marcus

It is not a good idea to power the MC33926 through an IO pin on the A-Star. I have attached a picture that shows a spot on the shield that you can solder a wire to the pullup on the EN line to get control of it.

ash03a_r17_en
ash03a_r17_en727×771 285 KB

Alternatively, you might could use the dual MC33926 motor driver carrier, that already breaks out the EN pin (as you pointed out). However, the dual MC33926 motor driver carrier does not have the same simplifying circuitry as the shield version, so it requires different control inputs and will not work with our MC33926 shield library.

Grant

3

thanks a lot for pointing out the right spot on the board - i will use the enable signal now.