I must be doing something dumb. I tried using the dual motor driver carrier (md18a) to drive a pair of small dc brush motors, but had no luck. I powered the carrier with 3.3V and the motors with 3.6V. I tried both VIN and VM, the latter bypassing polarity protection. I connected GND to my common ground. I pulled MODE up to 3.3V with a 1K resistor. I connected the motor to O1/O2. I drove EN1/PH1 to logic level HI/LO and LO/HI. The motor didn’t run. I checked all voltage levels. Everything looked OK, but the O1/O2 levels didn’t switch to 3.6V/0.0V as expected. I tried two different carriers. Motors run fine when connected directly to 3.6V. What am I missing?
Edit: A generic toy motor worked fine, so the coreless drone motors must pull too much current for the drivers. Kind of surprising, since I was driving the coreless motors with 2N2222 before. I solved it by disconnecting the motor and measuring the unloaded O1/O2 voltage, which switched as expected. No problem, I will just use logic level MOSFETs with reverse EMF diode. That should work fine. I am not sure the specs on the coreless motors. Must draw a lot of current.