Best motor driver?

[clytemnestra]

I want to make a small robot on my rpi3 and I'm looking for a motor driver but have no idea what to get from DRV8835, L9110S, L293D.

Also, what is best to control speed with? Analog or digital input?

[joan]

It depends on the motors you want to drive. The deciding factors would be the motor voltage and typical current usage.

[Trondwell13]

please - this is interesting but doesnt help.....let us say thay we want to achieve 0.1rpm on little torque - I am guessing but; 4-6volts and 0.1amps......just a way of controlling speed and direction.....i can get more sophisticated once i see the kit working..........no position control apart from controlling run time for instance.

Thanks

[clytemnestra]

They are going to be low current motors just enough to drive a small car.

[joan]

They are going to be low current motors just enough to drive a small car.

I'd look at a L9110S module. They are small and simple and inexpensive.

You can control the motor speed with PWM (the Pi can provide suitable PWM to all the GPIO connected to the expansion header).

[clytemnestra]

They are going to be low current motors just enough to drive a small car.

I'd look at a L9110S module. They are small and simple and inexpensive.

You can control the motor speed with PWM (the Pi can provide suitable PWM to all the GPIO connected to the expansion header).

Can I also count the rotations with that? Or the RPM? Or am I able to know what speed the motor has?

[joan]

Assuming ordinary DC motors you will need to add encoders to the wheels if you want to count rotations. The encoders would feed pulses back to a spare Pi GPIO.

Alternatively you could use stepper motors but they are slower and more difficult to drive (step) and need 4 spare GPIO per motor rather than two per DC motor (assuming you use the L9110S).

[clytemnestra]

OH, found encoders. They are optical, magnetical and electrical. Any idea which would be more accurate? Or doesn't matter?

Stepper motors aren't really a solution.