PWM motor control


I’m rebuilding a cheap fishing bait boat ( into something more intelligent with RPi3 / Navio2 / ArduPilot and I have a small question about motor control.

The motors of this boat ( are controlled with just two wires, I can see the signal is 7.4V PWM with duty cycle defining the rotation speed.

Is my understanding correct and I don’t need a ESC for it? What kind of off-the-shelf hardware could be used here?


Hello Maximo,

it seems it is a brushed motor. Indeed it can be driven modulated by PWM, but I think you need a brushed esc for it, because the current provided by the autopilot hardware is very little, not meant to drive any kind of motor. Check for a brushed esc and hook it between the motor and the autopilot and it will work great.

Best regards!

Thank you David! Any recommendations for brushed ESCs, maybe there are two channel models with 5V BEC on a market already (wishful thinking)?

Also, given that my controller is RPi and it is likely able to generate the required PWM for both motors, and voltage sensing is already done by power module - would it make sense to just use a simple motor driver here (like this, or it is not supported by ArduBoat?


Hi Max,
It seems we are using the same bait boat for our autonomous project! I’m also not sure how to set up the motors and ESC yet. I found some brushed waterproof ESCs on ebay but exactly how the setup will go I’m not sure yet. Have you got yours working yet?

Hi Alastair

Not yet, the final pieces to get the motors connected should arrive this week (hopefully) and I should be able to get the motors spinning this weekend (again, hopefully). Will report here, stay in touch!


Hi Max, sorry I didn’t respond I didn’t have notifications setup correctly. I’ve got my modified bait boat working fairly well. It will drive auto missions accurately however it only goes around 0.7 m/s which is a bit painful! Any update on your vehicle?

Hi Alastair,

Mine still looks like this, but I’m ready to connect motors once the motors issue is resolved. Since you solved this problem, would you mind commenting on your setup here - Boat skid steering ?

Also, it would be great if you could describe your components choice!