Arduino - Grove I2C Motor Driver

Recently I got a few Grove sensors, and as always I tried wiring it up with the Arduino and the Particle Core. Grove sensors are a series of senors form Seeed Studio, they have a wide range of sensors and components and I'm going to show you how to work with a few of these senors and components.

In this instructable I'm going to show you how to connect a Grove I2C Motor Driver, this is a two channel motor driver and communicates to the Arduino via I2C. This project serves as a starter to a more complicated robot project which I will post soon.

So lets get started....

Here are a list of components to gets started with the project -

• Arduino UNO
• Grove I2C Motor Shield
• Motor (3-15v)
• Suitable power supply to power the motor
• Jumper wires

Note- No soldering skills are required to build this project, but it is good to know how to solder there are a good soldering tutorials on YouTube that can help you get started.

The Grove I2C Motor Driver, has a dual channel H-Bridge (L298) which can handle 2A per channel. Controlled by an Atmel ATmega8L which handles the I2C communication.

I2C is a is 2 pin communication system the 2 lines are the SDA (data line) and SCL (clock line), this reduces the number of pins of the Arduino dedicated to drive the motor by connecting it directly to a L298 IC. There is a good documentation of Ardino I2C in the Arduino website, you can read to that to get started with I2C.

Now time for the connections the Arduino has the SCL line on analog pin 5 and SDA line on analog pin 4.

Here is how you need to connect he hardware -

• Arduino analog pin 5 - Grove I2C Motor Driver SCL
• Arduino analog pin 4 - Grove I2C Motor Driver SDA
• Arduino +5V - Grove I2C Motor Driver VCC
• Arduino Gnd - Grove I2C Motor Driver Gnd
• Power Supply + - Grove I2C Motor Driver VS

• Power Supply Gnd - Grove I2C Motor Driver Gnd

The Motor can be connected at Output 1 and 2 and if you are using 2 motors the other motor goes at output 3 and 4.

After you connect the hardware it is time to upload the code...

The code to be uploaded is a test sketch it just makes the motor run in one direction and then after some delay reverses the direction.

This is just a test sketch and if you need a specific task, leave a comment below and I will be happy to write the code for you.

#include 
#define MotorSpeedSet             0x82
#define PWMFrequenceSet           0x84
#define DirectionSet              0xaa
#define MotorSetA                 0xa1
#define MotorSetB                 0xa5
#define Nothing                   0x01
#define EnableStepper             0x1a
#define UnenableStepper           0x1b
#define Stepernu                  0x1c
#define I2CMotorDriverAdd         0x0f   // Set the address of the I2CMotorDriver
// set the steps you want, if 255, the stepper will rotate continuely;
void SteperStepset(unsigned char stepnu)
{
  Wire.beginTransmission(I2CMotorDriverAdd); // transmit to device I2CMotorDriverAdd
  Wire.write(Stepernu);          // Send the stepernu command 
  Wire.write(stepnu);            // send the steps
  Wire.write(Nothing);           // send nothing   
  Wire.endTransmission();        // stop transmitting 
}
///////////////////////////////////////////////////////////////////////////////
// Enanble the i2c motor driver to drive a 4-wire stepper. the i2c motor driver will
//driver a 4-wire with 8 polarity  .
//Direction: stepper direction ; 1/0
//motor speed: defines the time interval the i2C motor driver change it output to drive the stepper
//the actul interval time is : motorspeed * 4ms. that is , when motor speed is 10, the interval time 
//would be 40 ms
//////////////////////////////////////////////////////////////////////////////////
void StepperMotorEnable(unsigned char Direction, unsigned char motorspeed)
{
  Wire.beginTransmission(I2CMotorDriverAdd); // transmit to device I2CMotorDriverAdd
  Wire.write(EnableStepper);        // set pwm header 
  Wire.write(Direction);              // send pwma 
  Wire.write(motorspeed);              // send pwmb    
  Wire.endTransmission();    // stop transmitting 
}
//function to uneanble i2C motor drive to drive the stepper.
void StepperMotorUnenable()
{
  Wire.beginTransmission(I2CMotorDriverAdd); // transmit to device I2CMotorDriverAdd
  Wire.write(UnenableStepper);        // set unenable commmand
  Wire.write(Nothing);              
  Wire.write(Nothing);              
  Wire.endTransmission();    // stop transmitting 
}
//////////////////////////////////////////////////////////////////////
//Function to set the 2 DC motor speed
//motorSpeedA : the DC motor A speed; should be 0~100;
//motorSpeedB: the DC motor B speed; should be 0~100;
void MotorSpeedSetAB(unsigned char MotorSpeedA , unsigned char MotorSpeedB)  {
  MotorSpeedA=map(MotorSpeedA,0,100,0,255);
  MotorSpeedB=map(MotorSpeedB,0,100,0,255);
  Wire.beginTransmission(I2CMotorDriverAdd); // transmit to device I2CMotorDriverAdd
  Wire.write(MotorSpeedSet);        // set pwm header 
  Wire.write(MotorSpeedA);              // send pwma 
  Wire.write(MotorSpeedB);              // send pwmb    
  Wire.endTransmission();    // stop transmitting
}
//set the prescale frequency of PWM, 0x03 default;
void MotorPWMFrequenceSet(unsigned char Frequence)  {    
  Wire.beginTransmission(I2CMotorDriverAdd); // transmit to device I2CMotorDriverAdd
  Wire.write(PWMFrequenceSet);        // set frequence header
  Wire.write(Frequence);              //  send frequence 
  Wire.write(Nothing);              //  need to send this byte as the third byte(no meaning)  
  Wire.endTransmission();    // stop transmitting
}
//set the direction of DC motor. 
void MotorDirectionSet(unsigned char Direction)  {     //  Adjust the direction of the motors 0b0000 I4 I3 I2 I1
  Wire.beginTransmission(I2CMotorDriverAdd); // transmit to device I2CMotorDriverAdd
  Wire.write(DirectionSet);        // Direction control header
  Wire.write(Direction);              // send direction control information
  Wire.write(Nothing);              // need to send this byte as the third byte(no meaning)  
  Wire.endTransmission();    // stop transmitting 
}
void MotorDriectionAndSpeedSet(unsigned char Direction,unsigned char MotorSpeedA,unsigned char MotorSpeedB)  {  //you can adjust the driection and speed together
  MotorDirectionSet(Direction);
  MotorSpeedSetAB(MotorSpeedA,MotorSpeedB);  
}
void stepperrun()
{
 Serial.println("sent command to + direction, very fast");
 SteperStepset(255);
 StepperMotorEnable(1, 1);// ennable the i2c motor driver a stepper. 
  delay(5000);
  Serial.println("sent command to - direction, slow");
  SteperStepset(255);
  StepperMotorEnable(0, 20);
  delay(5000);
   Serial.println("sent command to - direction, fast");
  StepperMotorEnable(0, 2);// ennable the i2c motor driver a stepper. 
  delay(5000);
 Serial.println("sent command to + direction,100 steps, fast");
 SteperStepset(100);
  StepperMotorEnable(1,5);
 delay(3000);
 Serial.println("sent command to shut down the stepper");
 StepperMotorUnenable();
 delay(1000);
 
  Serial.println("sent command to - direction, slow, and 10 steps then stop");
 SteperStepset(10);
 StepperMotorEnable(0,40);
 delay(5000);
 Serial.println("sent command to shut down the stepper");
 StepperMotorUnenable();
 delay(5000);
}
void setup()  {
  Wire.begin(); // join i2c bus (address optional for master)
  delayMicroseconds(10000);
  Serial.begin(9600);
  Serial.println("setup begin");
  stepperrun();
}
void loop()  {
   while(1)  {
    MotorSpeedSetAB(100,100);
    delay(10); //this delay needed
    MotorDirectionSet(0b0110);  //0b1010  Rotating in the positive direction 
    delay(10000); 
    MotorDirectionSet(0b1001);  //0b0101  Rotating in the opposite direction
    delay(500);
  }
  
}