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Dual VNH5019 Motor Driver resolution (bits)?


Hi to all.
I have this Motor controller and I haven’t had troubles using it to controll two dc motors. The thing is, I’m using a PID controller to control motors, but I need shield resolution as one of those parameters. I now adafruit motor controller V2 has 4096 PWM resolution (on-board pwm chip with 12 bits resolution), but this shield?




Are you asking about the resolution available with the set speed commands in our VNH5019 shield library or the resolution of the PWM outputs connected to the PWM pins on the shield for some particular Arduino board? It might be helpful if you provide more information on your PID controller.



Thanks for your reply Claire. I’m asking for the PWM outputs connected to arduino board. I’m using dual vnh5019 motor driver shield, and I’d like to know that parameter. By the way, everything is working fine for me, but just I want to know it.
Thanks in advance



Hi, Gerson.

The PWM pins of the VNH5019 shield are connected to pins 9 and 10 on the Arduino. The resolution possible with those pins depends on the type of Arduino used and the timer on it that is associated with those pins. For controllers that use an ATmega328P or ATmega32U4, that is Timer1 which is a 16 bit timer.



Thanks again Claire. I’m using Arduino Mega 2560 which is based on ATmega2560 and I realize timers 1, 3, 4, 5 are 16 bit timers, but 0 and 2 are 8 bit timers. So, if I’m using interrupts 18 and 19 with 34 and 35 digital pins for reading two motors w/encoders which timers I’m using? I’m lost in that part. I hope you clarify me on that part.



In my previous posts I thought that you were asking about the resolution of the PWM output that would be going to the VNH5019 motor drivers, but now it sounds like what you are really interested in is the resolution you can get when reading some quadrature encoders. Is that the case?

By the way, reading encoder signals with interrupts does not involve any timers.



Yes, I’m interested in resolution reading quadrature encoders. Thanks for all, now I understand better that part.