Question

Design a circuit and Arduino program that accomplishes the following:

• An IR distance sensor will detect the presence (through waving of a hand)
• A H-Bridge circuit with 9V battery power will control the direction of the DC motor as described in Chapter 4 (pp. 70-79) of your textbook.
• When a hand is waved over the IR sensor, the motor moves in one direction (simulating opening a door). There is a 2 second pause, and then the motor moves in the opposite direction (simulating closing the door).
• The motor stops until another hand is waved over the IR sensor again.

Here is what I have. The code below runs the DC motor and stops when I cover the IR sensor and never changes directions. Please help with code! Maybe I have too much going on here.

//H-Bridge Sensor Motor Control Program

const int EN=9; //Half Bridge 1 Enable

const int MC1=3; //Motor Control 1

const int MC2=2; //Motor Control 2

const int distPin=0; //IR on Analog Pin 0

int val = 0; //for storing the reading from the IR

int velocity = 0; //For storing the desired velocity (from 0-255)

void setup()

{

pinMode(EN, OUTPUT);

pinMode(MC1, OUTPUT);

pinMode(MC2, OUTPUT);

brake(); //Initialize with motor stopped

}

void loop()

{

val = analogRead(distPin);

//go forward

if (val > 563)

{

  velocity = map(val, 563, 1023, 0, 255);

  forward(velocity);

}

//go backward

else if (val < 462)

{

  velocity = map(val, 461, 0, 0, 255);

  reverse(velocity);

}

//brake

else

{

  brake();

}

}

//Motor goes forward at given rate (from 0-255)

void forward (int rate)

{

digitalWrite(EN, LOW);

digitalWrite(MC1, HIGH);

digitalWrite(MC2, LOW);

analogWrite(EN, rate);

}

//Motor goes backward at given rate (from 0-255)

void reverse (int rate)

{

digitalWrite(EN, LOW);

digitalWrite(MC1, LOW);

digitalWrite(MC2, HIGH);

analogWrite(EN, rate);

}

//Stops motor

void brake ()

{

digitalWrite(EN, LOW);

digitalWrite(MC1, LOW);

digitalWrite(MC2, LOW);

digitalWrite(EN, HIGH);

}

Answer 1

You code is almost okay but need few changes. I edited the code, please try following code. I have simulated this code, and it is working fine. I used pin 6 and 7 to connect H bridge.

//H-Bridge Sensor Motor Control Program

const int EN=9; //Half Bridge 1 Enable

const int MC1=6; //Motor Control 1

const int MC2=7; //Motor Control 2

const int distPin=0; //IR on Analog Pin 0

int val = 0; //for storing the reading from the IR

void setup()

{

pinMode(EN, OUTPUT);

pinMode(MC1, OUTPUT);

pinMode(MC2, OUTPUT);

digitalWrite(EN, HIGH);

Serial.begin(9600);
brake(); //Initialize with motor stopped

}

void loop()

{

val = analogRead(distPin);
Serial.println(val);
if(val>462){
forward ();
reverse();
}
else {
brake();
}
}
//Motor goes forward at given rate (from 0-255)

void forward ()

{

digitalWrite(MC1, HIGH);

digitalWrite(MC2, LOW);

delay(2000);

}

//Motor goes backward at given rate (from 0-255)

void reverse ()

{

digitalWrite(MC1, LOW);

digitalWrite(MC2, HIGH);

delay(2000);
}

//Stops motor

void brake ()

{
digitalWrite(MC1, LOW);

digitalWrite(MC2, LOW);

}

If you get you motor reversing its direction, don't forget to thumbs up