I was looking into a motor driver to driver two separate brushed DC motors for a toy helicopter drone. My DC motors have a current requirement of 2.3A at about 8.4V. I only need the motor to spin in one direction for my two co-axial motors.
DRV8816 seems like a good fit for me. Im trying to achieve speed control by varying the average voltage on the motor windings. So PWM seems like a good idea, but I have a few questions about PWM implementation for speed control.
From the data sheet I see three modes when operating as Dual brushed motor -------- Off (coast), Forward and Brake.
During PWM , forward operation for the HIGH duration of PWM makes sense but I'm not sure whether I need brake or coast for the off duration of the PWM. Would this be brake or off? Whats the difference from a physical speed control point of view?
If I need brake I will connect PWM to the IN pin and EN always high, but
if I need coast, I will connect PWM to the EN pin and IN always high.
Wondering if someone can give me insights on which operation to use for speed control of motor using PWM for varying average DC voltage across windings?