Problems with Pololu 18v25 CS High Power Motor Driver

How to control a a dc motor using a Pololu High-Power Motor Driver 18v25 CS and an arduino uno ?

There is a lot of information on the Pololu website.

What are you having a problem with? What do you not understand?


I need to see the connections of pins from motor driver to arduino. I tried the way as mentioned in the website but motor driver is not giving any voltage across OUTA snd OUTB.

I have connected a pwm pin to PWMH, groud to ground, direction to a digital pin and digital pin to PWML and an external supply of 12 volts across V+ and GND of motor driver. This is the code I have used:

const int dir = 2;  
const int pwmh = 3;
const int pwml =4 ;

void setup() {
  pinMode(pwmh, OUTPUT);
  pinMode(dir, OUTPUT);
  pinMode(pwml, OUTPUT);
  digitalWrite(pwml, HIGH);

void loop() {

Make a pencil drawing showing how you have everything connected and post a photo of the drawing. Please don't use Fritzing.

A drawing is much less likely to be misunderstood compared to a verbal description.


And don't forget to monitor the fault flag outputs, that could be important information.

A clear wiring diagram (make sure to double-check so you show the precise setup you are using) plus the code is vital for us to fault-find. Tell us what currentyour 12V supply can produce and what your motor is.

how to connect a 18v dc geared motor to arduino mega 2560 ?....and how to control it ?

karthikeyan593: how to connect a 18v dc geared motor to arduino mega 2560 ?....and how to control it ?

How does this help @vyshakhmn ?


This is the connection . The voltage supply i have used is a variable dc power source with a max current rating of 10 A . The dc motor is a normal 300 rpm dc motor which works when directly connected to the v+ and gnd.

I havent checked the flags.

the code is posted in a previos post.

Well check the flags - if the controller is in a fault condition it won't be powering the motor.

how should i check the flag (the connection and the code) :D ?

Both flags were low when I checked it. should I connect reset to ground ?

i bought a high torque dc geared motor rmcs-2005 and motor drive to connect them to the arduino board mega 2560 ? how to control the speed of the motor ?

Reset should be connected and held high.

vyshakhmn: Both flags were low when I checked it.

Then its not detecting an error state. Eliminate all the possible problems till it works or you know what the issue is.