/*
MOTORA  |  AIN1 / BIN1   |   AIN2 / BIN2
-----------------------------------------
Forward |     HIGH       |      LOW   
-----------------------------------------
Reverse |     LOW        |      HIGH  
-----------------------------------------
STOP    |     LOW        |      LOW
-----------------------------------------
STOP    |     HIGH       |      HIGH
-----------------------------------------  
*/

// Motor A, Left Side  
const unit8_t AIN1 = 7
const unit8_t AIN2 = 8
const unit8_t PWMA = 5
const unit8_t ENA = A0
// Motor B, Right Side 
const unit8_t BIN1 = 4
const unit8_t BIN2 = 9
const unit8_t PWMB = 6
const unit8_t ENB = A1

void stop(){    
digitalWrite(AIN1, LOW);
digitalWrite(AIN2, LOW);
digitalWrite(BIN1, LOW);
digitalWrite(BIN2, LOW);
analogWrite(ENA, 0);
analogWrite(ENB, 0);
analogWrite(PWMA, 0);
analogWrite(PWMB, 0);   
}

void moveForward(){
analogWrite(ENA, 255);
analogWrite(ENB, 255);    
digitalWrite(AIN1, HIGH);
digitalWrite(AIN2, LOW);
digitalWrite(BIN1, HIGH);
digitalWrite(BIN2, LOW);    
analogWrite(PWMA, 255);
analogWrite(PWMB, 255);  
}

void moveReverse(){
analogWrite(ENA, 255);
analogWrite(ENB, 255);    
digitalWrite(AIN1, LOW);
digitalWrite(AIN2, HIGH);
digitalWrite(BIN1, LOW);
digitalWrite(BIN2, HIGH);    
analogWrite(PWMA, 255);
analogWrite(PWMB, 255);
}

void increaseForward(){
for (int i=0; i<256; i++){   
digitalWrite(AIN1, HIGH);
digitalWrite(AIN2, LOW);
digitalWrite(BIN1, HIGH);
digitalWrite(BIN2, LOW);    
analogWrite(PWMA, i);
analogWrite(PWMB, i);
analogWrite(ENA, 255);
analogWrite(ENB, 255);
delay(20);      
}
}

void setup() {
pinMode(AIN1, OUTPUT); //AIN1
pinMode(AIN2, OUTPUT); //AIN2
pinMode(BIN1, OUTPUT); //BIN1
pinMode(BIN2, OUTPUT); //BIN2
pinMode(ENA, OUTPUT); //ENA Enable Pin
pinMode(ENB, OUTPUT); //ENB Enable Pin
pinMode(PWMA, OUTPUT); //PWMA PWM pin for Motor A
pinMode(PWMB, OUTPUT); //PWMA PWM pin for Motor B
}

void loop(){
stop(); // Stop DC Motors
delay(3000);
moveForward(); // Drive DC Motors Forward
delay(3000);
moveReverse(); // Drive DC Motors Reverse
delay(3000);
increaseForward(); // Drive DC Motors 0 to 100 Forward
delay(3000);
}