Published January 2, 2026

Hand controlled robotic car

A robotic car that you can control with your hand!

IntermediateFull instructions provided62

Things used in this project

Hardware components

SparkFun Full-Bridge Motor Driver Breakout - L298N

DC Motor, 12 V

SparkFun Triple Axis Accelerometer and Gyro Breakout - MPU-6050

Espressif ESP32

Jumper wires (generic)

9V battery (generic)

AA Batteries

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Solder Wire, Lead Free

Story

The story:

I wanted to make a project about a robotic car since its a good way to get your self used to robotics but I also wanted it to be a bit unique not the standard robotic car that everyone builds so I decided to make it hand controlled.Now to how it works. I used cardboard as the base and put all the materials on it, I used two esp 32s so they can communicate with each other the communication was basically my hand moving (using an mpu 6500) and the robot recieving a message to move. The communication was made using esp now a protocol that allows two esp to "talk" to each other.

Controller and robot schematics

Connections
the controller has to have the following connections as shown by the photo above:

ESP // MPU

3V->VCC

GND -> GND

D21->SDA

D22->SCL
ESP // Battery

VN<-9v+

GND<-9v-

ESP//L298N

VIN->5V

GND->GND(you make this connection only once your code has been uploaded and you have disconected the usb port from the esp 32 )

ENA->D13

IN1->D14

IN2->D27

ENB->D25

IN3->D33

IN4->D32

Motor connections:

Motor//H-bridge

front wheels red wires -> OUT3

front wheels black wires->OUT4

(it doesnt matter how we put the you could do the opposite if you wish)

rear wheels red wires -> OUT2

rear wheels black wires -> OUT1

Battery//L298N

12V+ -> 12V

GND -> GND

Code

Code for both controller and robot

// After you do the programming using the following code :



#include <WiFi.h>

#include <esp_now.h>

#include <esp_wifi.h> // Required for channel locking

#include <Wire.h>



// --- Settings ---

const int MPU_ADDR = 0x68;

uint8_t broadcastAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; // Broadcast to everyone



// --- Data Structure ---

typedef struct struct_message {

int pitch;

int roll;

} struct_message;



struct_message myData;



void setup() {

Serial.begin(115200);

// 1. Initialize MPU6050 (Pins 21/22)

Wire.begin(21, 22);

Wire.beginTransmission(MPU_ADDR);

Wire.write(0x6B);

Wire.write(0);

Wire.endTransmission(true);



// 2. Set Wi-Fi Mode and LOCK CHANNEL 1

WiFi.mode(WIFI_STA);

esp_wifi_set_promiscuous(true);

esp_wifi_set_channel(1, WIFI_SECOND_CHAN_NONE); // This must be inside setup()!

esp_wifi_set_promiscuous(false);



// 3. Initialize ESP-NOW

if (esp_now_init() != ESP_OK) {

Serial.println("Error initializing ESP-NOW");

return;

}



// 4. Register Peer

esp_now_peer_info_t peerInfo = {};

memcpy(peerInfo.peer_addr, broadcastAddress, 6);

peerInfo.channel = 1;

peerInfo.encrypt = false;

esp_now_add_peer(&peerInfo);

Serial.println("Master Ready. Channel Locked to 1.");

}



void loop() {

// 5. Read MPU6050 Sensor

Wire.beginTransmission(MPU_ADDR);

Wire.write(0x3B);

Wire.endTransmission(false);

Wire.requestFrom(MPU_ADDR, 6, true);



int16_t acc_x = Wire.read()<<8 | Wire.read();

int16_t acc_y = Wire.read()<<8 | Wire.read();

int16_t acc_z = Wire.read()<<8 | Wire.read();



// 6. Calculate Tilt (Pitch)

float ay = acc_y / 16384.0;

float az = acc_z / 16384.0;

myData.pitch = (int)(atan2(ay, az) * 180.0 / PI);

myData.roll = 0;



// 7. Print to Serial Monitor

Serial.print("Master Pitch: ");

Serial.println(myData.pitch);



// 8. Send wirelessly to Slave

esp_now_send(broadcastAddress, (uint8_t *) &myData, sizeof(myData));

delay(100);

}

//Robot Programming :

#include <WiFi.h>

#include <esp_now.h>

#include <esp_wifi.h> // Required for channel locking



// --- Motor Pins ---

#define M_LEFT_IN1 14

#define M_LEFT_IN2 27

#define M_RIGHT_IN1 26

#define M_RIGHT_IN2 25



// --- Enable Pins (Speed Control) ---

#define M_LEFT_ENA 13

#define M_RIGHT_ENB 32



#define LED_PIN 2



typedef struct struct_message {

int pitch;

int roll;

} struct_message;



struct_message incomingData;



void driveRobot(int p) {

// Set Enable pins HIGH to give power to motors

digitalWrite(M_LEFT_ENA, HIGH);

digitalWrite(M_RIGHT_ENB, HIGH);



if (p > 50) { // Forward

digitalWrite(M_LEFT_IN1, HIGH); digitalWrite(M_LEFT_IN2, LOW);

digitalWrite(M_RIGHT_IN1, HIGH); digitalWrite(M_RIGHT_IN2, LOW);

Serial.println("Moving: FORWARD");

} else if (p < -50) { // Backward

digitalWrite(M_LEFT_IN1, LOW); digitalWrite(M_LEFT_IN2, HIGH);

digitalWrite(M_RIGHT_IN1, LOW); digitalWrite(M_RIGHT_IN2, HIGH);

Serial.println("Moving: BACKWARD");

} else { // Stop

digitalWrite(M_LEFT_IN1, LOW); digitalWrite(M_LEFT_IN2, LOW);

digitalWrite(M_RIGHT_IN1, LOW); digitalWrite(M_RIGHT_IN2, LOW);

digitalWrite(M_LEFT_ENA, LOW); digitalWrite(M_RIGHT_ENB, LOW);

Serial.println("Status: STOPPED");

}

}



void OnDataRecv(const esp_now_recv_info_t *info, const uint8_t *data, int len) {

memcpy(&incomingData, data, sizeof(incomingData));

digitalWrite(LED_PIN, !digitalRead(LED_PIN)); // Flicker blue light

driveRobot(incomingData.pitch);

}



void setup() {

Serial.begin(115200);

pinMode(LED_PIN, OUTPUT);

pinMode(M_LEFT_IN1, OUTPUT); pinMode(M_LEFT_IN2, OUTPUT);

pinMode(M_RIGHT_IN1, OUTPUT); pinMode(M_RIGHT_IN2, OUTPUT);

pinMode(M_LEFT_ENA, OUTPUT); pinMode(M_RIGHT_ENB, OUTPUT);



WiFi.mode(WIFI_STA);



// --- LOCK CHANNEL 1 ---

esp_wifi_set_promiscuous(true);

esp_wifi_set_channel(1, WIFI_SECOND_CHAN_NONE);

esp_wifi_set_promiscuous(false);



if (esp_now_init() != ESP_OK) {

Serial.println("Error initializing ESP-NOW");

return;

}

esp_now_register_recv_cb(OnDataRecv);

Serial.println("Slave Ready. Channel Locked to 1.");

}



void loop() {}