Hello all. For context, I am a MechE student whose trying to become more proficient with electronics over the summer and I decided to build an RC car using Pololu’s VNH5019 motor driver (https://www.pololu.com/product/2507), an Arduino Uno, two 12V DC motors (https://www.pololu.com/product/4741/specs), and an HC-05 bluetooth module. I am powering the Arduino and the motor shield separately. More specifically, I’m using a 9V battery for my Arduino and 8 AA batteries to power my motor driver. The bluetooth module is connected to an app on my phone, which should allow me to control the motors. However, whenever everything is connected, no voltage seems to go to the motors.
I’ve scoured the internet for reasons as to why this is happening and I believe there are seem to be two, common causes for this. One, lack of common ground (which I fixed but still no response from the motors). And two, not enough current being drawn from the batteries. I suspect the latter is the cause since I’m using alkaline batteries. If this were the problem, I would need to buy new batteries but I would rather not. Thus, I would like to double check with the community to see what they think: Do you think my AA alkaline batteries are at fault and should I get new ones (i.e. Li ion batteries)?
Also, do I need to supply the motor driver with enough voltage for both it and the motors to run? Or is it just enough to provide it the 12V needed for the motors to run since that’s within the motor driver’s voltage-range as well.