Issue running DC Motor off Adafruit TB6612

Dear Arduino Community,

I am having trouble running a 12V DC peristaltic pump motor with the Adafruit TB6612 Driver and an Arduino uno.

Right now all that happens is that I hear sound coming from the motor, but no turning. I am not sure if it is my wiring that is wrong or whether it is my power supply(which is a 9V battery).

My goal is to vary output of the peristaltic pump via pressure of a fsr. This is my code thus far. Not sure if there is something wrong with the code either.

int fsrPin = 0;
int fsrReading;

//motor readings
const int pmw =3;
const int input1=7;
const int input2=8;

void setup(void) {
pinMode(pmw, OUTPUT);
pinMode(input1, OUTPUT);
pinMode(input2, OUTPUT);

void loop() {
fsrReading = analogRead(fsrPin);
// Serial.print("Analog reading = ");
// Serial.print(fsrReading);

digitalWrite(input1, HIGH);
digitalWrite(input2, LOW);
Serial.print(“Test scenerio 1 PWM 255”);


// digitalWrite(input1, LOW);
// digitalWrite(input2, HIGH);
// analogWrite(pmw,125);
// Serial.print(“Test scenerio 2 PWM 125”);

// delay(10000);

// digitalWrite(input1, LOW);
// digitalWrite(input2, LOW);
// analogWrite(pmw,125);
// Serial.print(“Test scenerio BREAK PWM 125”);


I have attached a photo of the current way I have wired this.

Thank you guys for your time and help. I appreciate any input of what potentially I should change.

The most likely problem is that your little 9V battery simply doesn’t have enough power to run the motor. Try replacing it with 4 (or 6) AA batteries and see what happens.


The TB6612 can handle just over an amp, check that your pump is OK with this...

Hi all,

Thank you for your thoughts. I figured out that the 9V battery was old and only had 4.5 V. Switching to a new battery fixed things.