Circuit Documentation

Summary

This circuit is designed to interface an Arduino Nano with an NRF24L01 wireless transceiver and an InvenSense MPU6050 accelerometer and gyroscope sensor. The circuit is powered by a 3.7V LiPo battery. The Arduino Nano reads data from the MPU6050 sensor and transmits it wirelessly using the NRF24L01 module.

Component List

1. Arduino Nano

   • Description: A small, complete, and breadboard-friendly board based on the ATmega328P.
   • Pins: D1/TX, D0/RX, RESET, GND, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11/MOSI, D12/MISO, VIN, 5V, A7, A6, A5, A4, A3, A2, A1, A0, AREF, 3V3, D13/SCK

2. NRF24L01

   • Description: A wireless transceiver module for low-power, high-speed communication.
   • Pins: IRQ (not used), MOSI, CSN, VCC (3V), GND, CE, SCK, MISO

3. InvenSense MPU6050

   • Description: A 6-axis motion tracking device that combines a 3-axis gyroscope and a 3-axis accelerometer.
   • Pins: VCC, GND, SCL, SDA, XDA, XCL, AD0, INT

4. 3.7V LiPo Battery

   • Description: A rechargeable lithium polymer battery.
   • Pins: +Ve, GND

Wiring Details

Arduino Nano

• D9 connected to CE of NRF24L01
• D10 connected to CSN of NRF24L01
• D11/MOSI connected to MOSI of NRF24L01
• D12/MISO connected to MISO of NRF24L01
• VIN connected to +Ve of 3.7V LiPo Battery
• GND connected to GND of 3.7V LiPo Battery, NRF24L01, and InvenSense MPU6050
• A5 connected to SCL of InvenSense MPU6050
• A4 connected to SDA of InvenSense MPU6050
• 3V3 connected to VCC (3V) of NRF24L01 and VCC of InvenSense MPU6050
• D13/SCK connected to SCK of NRF24L01

NRF24L01

• CE connected to D9 of Arduino Nano
• CSN connected to D10 of Arduino Nano
• MOSI connected to D11/MOSI of Arduino Nano
• MISO connected to D12/MISO of Arduino Nano
• VCC (3V) connected to 3V3 of Arduino Nano
• GND connected to GND of 3.7V LiPo Battery, Arduino Nano, and InvenSense MPU6050
• SCK connected to D13/SCK of Arduino Nano

InvenSense MPU6050

• VCC connected to 3V3 of Arduino Nano
• GND connected to GND of 3.7V LiPo Battery, Arduino Nano, and NRF24L01
• SCL connected to A5 of Arduino Nano
• SDA connected to A4 of Arduino Nano

3.7V LiPo Battery

• +Ve connected to VIN of Arduino Nano
• GND connected to GND of Arduino Nano, NRF24L01, and InvenSense MPU6050

Code Documentation

Arduino Nano Code

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
#include <Wire.h>
#include <MPU6050.h>

// NRF24L01 Pins
#define CE_PIN 9
#define CSN_PIN 10

RF24 radio(CE_PIN, CSN_PIN);
const byte address[6] = "00001"; // Communication address

// Variables for MPU6050
MPU6050 mpu;
int16_t ax, ay, az, gx, gy, gz;
float pitch, roll, yaw;

// Variables for throttle and control
int throttle = 0; // Throttle value (0 to 255)
int data[4];      // Array to store [throttle, yaw, pitch, roll]

void setup() {
  // Initialize Serial for debugging
  Serial.begin(9600);

  // Initialize MPU6050
  Wire.begin();
  mpu.initialize();
  if (!mpu.testConnection()) {
    Serial.println("MPU6050 connection failed");
    while (1); // Stop if the connection fails
  }

  // Initialize RF24
  radio.begin();
  radio.openWritingPipe(address);
  radio.setPALevel(RF24_PA_LOW);
  radio.stopListening();

  // Debug message
  Serial.println("Controller is ready!");
}

void loop() {
  // Read MPU6050 data
  mpu.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);

  // Calculate pitch and roll
  pitch = atan2(ax, sqrt(ay * ay + az * az)) * 180 / PI;
  roll = atan2(ay, sqrt(ax * ax + az * az)) * 180 / PI;
  yaw = gx / 131.0; // Approximate yaw from gyroscope

  // Debugging sensor data
  Serial.print("Pitch: "); Serial.print(pitch);
  Serial.print(" Roll: "); Serial.print(roll);
  Serial.print(" Yaw: "); Serial.println(yaw);

  // Map pitch, roll, and yaw to control values (0-255)
  data[0] = throttle; // Throttle remains constant for now
  data[1] = map(yaw, -90, 90, 0, 255);
  data[2] = map(pitch, -90, 90, 0, 255);
  data[3] = map(roll, -90, 90, 0, 255);

  // Send data to the drone
  bool success = radio.write(&data, sizeof(data));
  if (success) {
    Serial.println("Data sent!");
  } else {
    Serial.println("Data send failed.");
  }

  delay(50); // Small delay for stability
}

This code initializes the MPU6050 sensor and the NRF24L01 transceiver, reads sensor data, calculates pitch, roll, and yaw, maps these values to control values, and sends the data wirelessly to a receiver.