Circuit Documentation

Summary

This circuit is designed to control a DC motor and a servo motor using two Arduino boards (UNO and Nano) and wireless communication via NRF24L01 modules. The Arduino UNO acts as the receiver, controlling the motors based on the data received from the transmitter, which is the Arduino Nano. The Nano reads analog values from a dual-axis joystick module and sends these values wirelessly to the UNO. The UNO then maps these values to control the speed and direction of the DC motor using an L298N motor driver and the position of the servo motor.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Used as the main controller for receiving data and controlling the motors

NRF24L01 (Receiver)

• 2.4GHz wireless transceiver module
• Connected to the Arduino UNO for receiving control signals

DC Motor

• Electric motor that converts electrical energy into mechanical energy
• Controlled by the L298N motor driver

L298N DC Motor Driver

• Dual H-bridge motor driver module
• Drives the DC motor based on signals from the Arduino UNO

Battery AAx4 6V

• Power source for the motor driver and the DC motor

Servo

• Rotary actuator that allows for precise control of angular position
• Controlled directly by the Arduino UNO

Arduino Nano

• Small, complete, and breadboard-friendly microcontroller board based on the ATmega328P
• Used as the transmitter to send control signals to the Arduino UNO

NRF24L01 (Transmitter)

• 2.4GHz wireless transceiver module
• Connected to the Arduino Nano for sending control signals

KY-023 Dual Axis Joystick Module (x2)

• Analog joystick with a push-button
• Used to capture user input for controlling the motors

Wiring Details

Arduino UNO

• 3.3V to NRF24L01 VCC (Receiver)
• 5V to Servo VCC
• GND to NRF24L01 GND (Receiver), Servo GND, L298N GND, and Battery GND
• D13 to NRF24L01 SCK (Receiver)
• D12 to NRF24L01 MISO (Receiver)
• D11 to NRF24L01 MOSI (Receiver)
• D10 to NRF24L01 CSN (Receiver)
• D9 to NRF24L01 CE (Receiver)
• D6 to L298N ENB
• D5 to L298N IN3
• D4 to L298N IN4
• D3 to Servo PWM

NRF24L01 (Receiver)

• Connected as detailed above in the Arduino UNO section

DC Motor

• pin 1 to L298N OUT4
• pin 2 to L298N OUT3

L298N DC Motor Driver

• OUT3 and OUT4 to DC Motor
• 12V to Battery VCC
• GND to Battery GND
• ENB to Arduino UNO D6
• IN3 to Arduino UNO D5
• IN4 to Arduino UNO D4

Battery AAx4 6V

• VCC to L298N 12V
• GND to L298N GND

Servo

• VCC to Arduino UNO 5V
• GND to Arduino UNO GND
• PWM to Arduino UNO D3

Arduino Nano

• 3V3 to NRF24L01 VCC (Transmitter)
• GND to NRF24L01 GND (Transmitter), KY-023 GND (x2)
• 5V to KY-023 +5V (x2)
• D9 to NRF24L01 CE (Transmitter)
• D10 to NRF24L01 CSN (Transmitter)
• D11/MOSI to NRF24L01 MOSI (Transmitter)
• D12/MISO to NRF24L01 MISO (Transmitter)
• D13/SCK to NRF24L01 SCK (Transmitter)
• A0 to KY-023 VRx (Joystick 1)
• A1 to KY-023 VRx (Joystick 2)

NRF24L01 (Transmitter)

• Connected as detailed above in the Arduino Nano section

KY-023 Dual Axis Joystick Module (x2)

• GND to Arduino Nano GND
• +5V to Arduino Nano 5V
• VRx to Arduino Nano A0 (Joystick 1) and A1 (Joystick 2)

Documented Code

Arduino UNO Code (Receiver)

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
#include <Servo.h>

Servo myservo;

// Set the CE and CSN pins
RF24 radio(9, 10);

// Create a pipe for communication
const byte address[6] = "00001"; 

int motorPin1 = 4;
int motorPin2 = 5; 
int mappedServoValue;
int mappedMotorValue;

// Structure to hold the received variables
struct DataPackage {
  int motorValue;
  int servoValue;
};

DataPackage data;

void setup() {
  Serial.begin(9600);
  myservo.attach(3);

  pinMode(5, OUTPUT);
  pinMode(4, OUTPUT);

  digitalWrite(motorPin1, HIGH);
  digitalWrite(motorPin2, LOW);
  
  // Initialize the NRF24L01 module
  radio.begin();
  
  // Open the same pipe as the transmitter for reading
  radio.openReadingPipe(0, address);
  
  // Set the radio in receiver mode
  radio.setPALevel(RF24_PA_MIN);
  radio.startListening(); // Start listening for data
}

void loop() {
  if (radio.available()) { // Check if data is available
    radio.read(&data, sizeof(data)); // Read the incoming data structure

    mappedMotorValue = map(data.motorValue,500,1023,0,255);
    if (data.motorValue > 510) {
      analogWrite(6,mappedMotorValue);
    }
    else {
      analogWrite(6,0);
    }

    mappedServoValue = map(data.servoValue,0,1023,180,0);
    if (mappedServoValue >= 0){
      myservo.write(mappedServoValue);
    }
    else {
      myservo.write(90);
    }

    // Print the received variables
    Serial.print("MOTOR: ");
    Serial.print(data.motorValue);
    Serial.print(" -> ");
    Serial.print(mappedMotorValue);
    Serial.print("   \tSERVO: ");
    Serial.print(data.servoValue);
    Serial.print(" -> ");
    Serial.println(mappedServoValue);
  }
}

Arduino Nano Code (Transmitter)

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>

// Set the CE and CSN pins
RF24 radio(9, 10);

// Create a pipe for communication
const byte address[6] = "00001"; 

// Structure to hold the received variables
struct DataPackage {
  int motorValue;
  int servoValue;
};

DataPackage data;

#define MOTOR_PIN  A4 // Arduino pin connected to VRX pin
#define SERVO_PIN  A3 // Arduino pin connected to VRY pin

int xValue = 0; // To store value of the X axis
int yValue = 0; // To store value of the Y axis

void setup() {
  Serial.begin(9600) ;

  // Initialize the NRF24L01 module
  radio.begin();
  
  // Set the address to the pipe for writing
  radio.openWritingPipe(address);
  
  // Set the radio in transmitter mode
  radio.setPALevel(RF24_PA_MIN);
}

void loop() {
  // read analog X and Y analog values
  data.motorValue = analogRead(MOTOR_PIN);
  data.servoValue = analogRead(SERVO_PIN);

  // Set module to transmit mode
  radio.stopListening();

  // Send the data structure
  bool success = radio.write(&data, sizeof(data));
  
  if (success) {
    Serial.print("[SENT]\t");
  } else {
    Serial.print("[NOT SENT]\t");
  }

  // print data to Serial Monitor on Arduino IDE
  Serial.print("MOTOR: ");
  Serial.print(data.motorValue);
  Serial.print("\tSERVO: ");
  Serial.println(data.servoValue);

  delay(100);
}

This documentation provides an overview of the circuit, including a description of each component, wiring details, and the embedded code for the microcontrollers. The code sections are documented to explain the functionality of the receiver and transmitter in the wireless control system.