//project for designing electronic toys, written by Toma Ogawa

//Assigning pin numbers. n for negative and p for positive
int motor_right_n = 2;
int motor_right_p = 3;
int motor_left_p = 4;
int motor_left_n = 5;
//EnA and EnB take the analog PWM input for motors 1 and 2 respectively.
int EnA = 9;
int EnB = 10;
//receives the character sent by the laptop over the Tera Term terminal input.
int incomingByte = 0;

void setup()

{
//assigning pins
pinMode(motor_right_n, OUTPUT);
pinMode(motor_right_p, OUTPUT);
pinMode(motor_left_p, OUTPUT);
pinMode(motor_left_n, OUTPUT);
pinMode(EnA, OUTPUT);
pinMode(EnB, OUTPUT);

//making sure everything is off at the start.
digitalWrite(motor_right_n, LOW);
digitalWrite(motor_right_p, LOW);
digitalWrite(motor_left_p, LOW);
digitalWrite(motor_left_n, LOW);
digitalWrite(EnA, LOW);
digitalWrite(EnB, LOW);

//setting baud rate for connection over HC-06 bluetooth module.
Serial.begin(9600);
Serial.println("start");

}

void loop()

{
if (Serial.available() > 0) {
//reads character input from laptop
incomingByte = Serial.read();
}

//select case depending on character
switch(incomingByte)
{
//see slide for combinations of digitalWrite values

case 's':
digitalWrite(motor_right_n, LOW); // control for stop
digitalWrite(motor_right_p, LOW);
digitalWrite(motor_left_p, LOW);
digitalWrite(motor_left_n, LOW);
analogWrite(EnA, 0);
analogWrite(EnB, 0);
Serial.println("Stop\n");
incomingByte='*';
break;

case 'd':
digitalWrite(motor_right_n, HIGH); // control for right
digitalWrite(motor_right_p, LOW);
digitalWrite(motor_left_p, HIGH);
digitalWrite(motor_left_n, LOW);
analogWrite(EnA, 200);
Serial.println("right\n");
incomingByte='*';
break;

case 'a':
digitalWrite(motor_right_n, LOW); // control for left
digitalWrite(motor_right_p, HIGH);
digitalWrite(motor_left_p, LOW);
digitalWrite(motor_left_n, HIGH);
analogWrite(EnB, 200);
Serial.println("left\n");
incomingByte='*';
break;

case 'w':
digitalWrite(motor_right_n, HIGH); // control for forward
digitalWrite(motor_right_p, LOW);
digitalWrite(motor_left_p, LOW);
digitalWrite(motor_left_n, HIGH);
analogWrite(EnA, 200);
analogWrite(EnB, 200);
Serial.println("forward\n");
incomingByte='*';
break;

case 'x':
digitalWrite(motor_right_n, LOW); // control for backward
digitalWrite(motor_right_p, HIGH);
digitalWrite(motor_left_p, HIGH);
digitalWrite(motor_left_n, LOW);
analogWrite(EnA, 200);
analogWrite(EnB, 200);
Serial.println("backwards\n");
incomingByte='*';
break;

delay(5000);

}
}