Smartphone Controlled Arduino 4WD Robot Car

Hi everyone! This is my next project, a smartphone-controlled Arduino 4WD robot car or Bluetooth Arduino robot. It can move forward and backward, left and right, change its speed, turn on / off front and back lights and also it can horn.

This is a quite simple design robot you can easily build it.

Step 1: Requirements

Parts Required:

• Arduino Uno R3 Board

• Chassis 4WD with DC Motor and Wheel x4

• Motor Driver L298N x2

• Bluetooth module HC-06

• Li-ion battery 18650 x2

• LEDs + resistors 220 Ohm x4

• Buzzer

Step 2: Assembling a 4WD Robot Smart Car Chassis

This is my video: How to Assemble a 4WD Robot Smart Car Chassis Kit.

Step 3: Wiring Diagram

Make connections as in the wiring diagram image above.

Step 4: Upload Robot Code

#define light_FR  14    //LED Front Right   pin A0 for Arduino Uno
#define light_FL  15    //LED Front Left    pin A1 for Arduino Uno #define light_BR  16    //LED Back Right    pin A2 for Arduino Uno #define light_BL  17    //LED Back Left     pin A3 for Arduino Uno #define horn_Buzz 18    //Horn Buzzer       pin A4 for Arduino Uno
#define ENA_m1 5        // Enable/speed motor Front Right  #define ENB_m1 6        // Enable/speed motor Back Right #define ENA_m2 10       // Enable/speed motor Front Left #define ENB_m2 11       // Enable/speed motor Back Left
#define IN_11  2      // L298N #1 in 1 motor Front Right #define IN_12  3      // L298N #1 in 2 motor Front Right #define IN_13  4      // L298N #1 in 3 motor Back Right #define IN_14  7      // L298N #1 in 4 motor Back Right
#define IN_21  8      // L298N #2 in 1 motor Front Left #define IN_22  9      // L298N #2 in 2 motor Front Left #define IN_23  12     // L298N #2 in 3 motor Back Left #define IN_24  13     // L298N #2 in 4 motor Back Left
int command;          //Int to store app command state. int speedCar = 100;   // 50 - 255. int speed_Coeff = 4; boolean lightFront = false; boolean lightBack = false; boolean horn = false;
void setup() {          pinMode(light_FR, OUTPUT);     pinMode(light_FL, OUTPUT);     pinMode(light_BR, OUTPUT);     pinMode(light_BL, OUTPUT);     pinMode(horn_Buzz, OUTPUT);         pinMode(ENA_m1, OUTPUT);    pinMode(ENB_m1, OUTPUT);    pinMode(ENA_m2, OUTPUT);    pinMode(ENB_m2, OUTPUT);        pinMode(IN_11, OUTPUT);     pinMode(IN_12, OUTPUT);     pinMode(IN_13, OUTPUT);     pinMode(IN_14, OUTPUT);          pinMode(IN_21, OUTPUT);     pinMode(IN_22, OUTPUT);     pinMode(IN_23, OUTPUT);     pinMode(IN_24, OUTPUT);
Serial.begin(9600); 
} 
void goAhead(){ 
digitalWrite(IN_11, HIGH);       digitalWrite(IN_12, LOW);      analogWrite(ENA_m1, speedCar);
digitalWrite(IN_13, LOW);       digitalWrite(IN_14, HIGH);      analogWrite(ENB_m1, speedCar);
digitalWrite(IN_21, LOW);       digitalWrite(IN_22, HIGH);      analogWrite(ENA_m2, speedCar);
digitalWrite(IN_23, HIGH);       digitalWrite(IN_24, LOW);      analogWrite(ENB_m2, speedCar);
}
void goBack(){ 
digitalWrite(IN_11, LOW);       digitalWrite(IN_12, HIGH);      analogWrite(ENA_m1, speedCar);
digitalWrite(IN_13, HIGH);       digitalWrite(IN_14, LOW);      analogWrite(ENB_m1, speedCar);
digitalWrite(IN_21, HIGH);       digitalWrite(IN_22, LOW);      analogWrite(ENA_m2, speedCar);
digitalWrite(IN_23, LOW);       digitalWrite(IN_24, HIGH);      analogWrite(ENB_m2, speedCar);
}
void goRight(){ 
digitalWrite(IN_11, LOW);       digitalWrite(IN_12, HIGH);      analogWrite(ENA_m1, speedCar);
digitalWrite(IN_13, HIGH);       digitalWrite(IN_14, LOW);      analogWrite(ENB_m1, speedCar);
digitalWrite(IN_21, LOW);       digitalWrite(IN_22, HIGH);      analogWrite(ENA_m2, speedCar);
digitalWrite(IN_23, HIGH);       digitalWrite(IN_24, LOW);      analogWrite(ENB_m2, speedCar);
}
void goLeft(){
digitalWrite(IN_11, HIGH);       digitalWrite(IN_12, LOW);      analogWrite(ENA_m1, speedCar);
digitalWrite(IN_13, LOW);       digitalWrite(IN_14, HIGH);      analogWrite(ENB_m1, speedCar);
digitalWrite(IN_21, HIGH);       digitalWrite(IN_22, LOW);      analogWrite(ENA_m2, speedCar);
digitalWrite(IN_23, LOW);       digitalWrite(IN_24, HIGH);      analogWrite(ENB_m2, speedCar);
}
void goAheadRight(){              digitalWrite(IN_11, HIGH);       digitalWrite(IN_12, LOW);       analogWrite(ENA_m1, speedCar/speed_Coeff);
digitalWrite(IN_13, LOW);       digitalWrite(IN_14, HIGH);       analogWrite(ENB_m1, speedCar/speed_Coeff);
digitalWrite(IN_21, LOW);       digitalWrite(IN_22, HIGH);       analogWrite(ENA_m2, speedCar);
digitalWrite(IN_23, HIGH);       digitalWrite(IN_24, LOW);       analogWrite(ENB_m2, speedCar);     }
void goAheadLeft(){              digitalWrite(IN_11, HIGH);       digitalWrite(IN_12, LOW);       analogWrite(ENA_m1, speedCar);
digitalWrite(IN_13, LOW);       digitalWrite(IN_14, HIGH);       analogWrite(ENB_m1, speedCar);
digitalWrite(IN_21, LOW);       digitalWrite(IN_22, HIGH);       analogWrite(ENA_m2, speedCar/speed_Coeff);
digitalWrite(IN_23, HIGH);       digitalWrite(IN_24, LOW);       analogWrite(ENB_m2, speedCar/speed_Coeff);     }
void goBackRight(){ 
digitalWrite(IN_11, LOW);       digitalWrite(IN_12, HIGH);       analogWrite(ENA_m1, speedCar/speed_Coeff);
digitalWrite(IN_13, HIGH);       digitalWrite(IN_14, LOW);       analogWrite(ENB_m1, speedCar/speed_Coeff);
digitalWrite(IN_21, HIGH);       digitalWrite(IN_22, LOW);       analogWrite(ENA_m2, speedCar);
digitalWrite(IN_23, LOW);       digitalWrite(IN_24, HIGH);       analogWrite(ENB_m2, speedCar);
}
void goBackLeft(){ 
digitalWrite(IN_11, LOW);       digitalWrite(IN_12, HIGH);       analogWrite(ENA_m1, speedCar);
digitalWrite(IN_13, HIGH);       digitalWrite(IN_14, LOW);       analogWrite(ENB_m1, speedCar);
digitalWrite(IN_21, HIGH);       digitalWrite(IN_22, LOW);       analogWrite(ENA_m2, speedCar/speed_Coeff);
digitalWrite(IN_23, LOW);       digitalWrite(IN_24, HIGH);       analogWrite(ENB_m2, speedCar/speed_Coeff);
}
void stopRobot(){ 
digitalWrite(IN_11, LOW);       digitalWrite(IN_12, LOW);      analogWrite(ENA_m1, speedCar);
digitalWrite(IN_13, LOW);       digitalWrite(IN_14, LOW);      analogWrite(ENB_m1, speedCar);
digitalWrite(IN_21, LOW);       digitalWrite(IN_22, LOW);      analogWrite(ENA_m2, speedCar);
digitalWrite(IN_23, LOW);       digitalWrite(IN_24, LOW);      analogWrite(ENB_m2, speedCar);      }    void loop(){    if (Serial.available() > 0) {  command = Serial.read();  stopRobot();    //Initialize with motors stopped.
if (lightFront) {digitalWrite(light_FR, HIGH); digitalWrite(light_FL, HIGH);} if (!lightFront) {digitalWrite(light_FR, LOW); digitalWrite(light_FL, LOW);} if (lightBack) {digitalWrite(light_BR, HIGH); digitalWrite(light_BL, HIGH);} if (!lightBack) {digitalWrite(light_BR, LOW); digitalWrite(light_BL, LOW);} if (horn) {digitalWrite(horn_Buzz, HIGH);} if (!horn) {digitalWrite(horn_Buzz, LOW);}
switch (command) { case 'F':goAhead();break; case 'B':goBack();break; case 'L':goLeft();break; case 'R':goRight();break; case 'I':goAheadRight();break; case 'G':goAheadLeft();break; case 'J':goBackRight();break; case 'H':goBackLeft();break; case '0':speedCar = 100;break; case '1':speedCar = 115;break; case '2':speedCar = 130;break; case '3':speedCar = 145;break; case '4':speedCar = 160;break; case '5':speedCar = 175;break; case '6':speedCar = 190;break; case '7':speedCar = 205;break; case '8':speedCar = 220;break; case '9':speedCar = 235;break; case 'q':speedCar = 255;break; case 'W':lightFront = true;break; case 'w':lightFront = false;break; case 'U':lightBack = true;break; case 'u':lightBack = false;break; case 'V':horn = true;break; case 'v':horn = false;break;
} } }

Step 5: Notes

Before uploading the code you have to disconnect Bluetooth module from Arduino Uno board (pins 0, 1).

Step 6: Downloading Android App

Arduino Bluetooth RC Car

Step 7: Connecting Bluetooth Module

To connect your smartphone to Arduino Bluetooth module HC-06 we have to enter PIN CODE 1234 or 0000.

Step 8: Finish

That it once you made all steps properly robot is ready to go!

Thank you all!