Hey everyone,
I am working on a project where I need to control three of the Micro Metal Gearmotor MP 6v motors: Pololu - 100:1 Micro Metal Gearmotor MP 6V with Extended Motor Shaft
I am using the DRV8876 break out for each of the motors: Pololu - DRV8876 (QFN) Single Brushed DC Motor Driver Carrier
And I am using the 6v Step-Up Voltage Regulator to boost my single cell lipo to 6v: Pololu - 6V Step-Up Voltage Regulator U3V16F6
For my microcontroller, I have been testing it with the TinyPico and the Feather ESP32 board. I have both a breadboard setup and a custom PCB I made for this project. The issue I am facing is when I attempt to control the motor, the microcontroller constantly resets or is in a brownout state. I believe what is happening is when the motor starts, there is a large current spike and a voltage drop that causes the micro to reset and repeat over and over.
I have tried using the larger 6v supply - Pololu - 6V Step-Up Voltage Regulator U3V40F6 - with no luck. I have added some decoupling caps to the input and output of the 6v and a large 470uF electrolytic on my VIN and GND on the micro. When I use my bench supply, everything works fine. I have also tried a few different lipos. I was hoping the larger 6v step-up would solve my problem, but it didn’t, and I’m quite stuck right now. I am only attempting to run one motor at half speed right now. I could implement some PWM ramping in my code, but I fear that when I control all three motors at once, this issue will kick in. Any ideas here?