Circuit Documentation

Summary of the Circuit

The circuit described in the provided inputs is a bus stop system that utilizes an Arduino UNO as the central microcontroller. The system is designed to read GPS data from a Neo 6M GPS Module, play audio announcements through a DFPlayer MINI module connected to a Loudspeaker, and display information on an LCD screen 16x2 with I2C interface. The circuit is powered by a 12V 5A Power Supply, and a DC-DC converter is used to step down the voltage to a level suitable for the Arduino and other components.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• It has digital I/O pins, analog input pins, and various power pins.
• Used as the main controller for interfacing with the GPS module, DFPlayer MINI, and LCD screen.

Neo 6M GPS Module

• A GPS receiver module that provides location data.
• Communicates with the Arduino via serial TX and RX pins.

DFPlayer MINI

• A compact audio player module that can play files from a microSD card.
• Interfaces with the Arduino through serial communication for playing audio announcements.

POWER SUPPLY 12V 5AMP

• Provides the necessary power to the circuit.
• Outputs 12V-24V DC from a 220V AC input.

LCD screen 16x2 I2C

• An alphanumeric liquid crystal display with 16 characters by 2 lines.
• Uses I2C communication to display data from the Arduino.

DC DC converter

• Steps down the voltage from the power supply to a lower voltage suitable for the Arduino and other components.

Loudspeaker

• An audio output device connected to the DFPlayer MINI to play sound.

Wiring Details

Arduino UNO

• 5V pin connected to the VCC pins of the LCD screen, Neo 6M GPS Module, and DFPlayer MINI.
• GND pin connected to the GND pins of the LCD screen, Neo 6M GPS Module, DFPlayer MINI, and the GND OUT of the DC DC converter.
• Vin pin connected to the +VCC OUT of the DC DC converter.
• A4 (SDA) pin connected to the SDA pin of the LCD screen.
• A5 (SCL) pin connected to the SCL pin of the LCD screen.
• D11 pin connected to the TX pin of the DFPlayer MINI.
• D10 pin connected to the RX pin of the DFPlayer MINI.
• D3 pin connected to the RX pin of the Neo 6M GPS Module.
• D2 pin connected to the TX pin of the Neo 6M GPS Module.

Neo 6M GPS Module

• VCC pin connected to the 5V output from the Arduino.
• GND pin connected to the common ground.
• TX pin connected to the D2 pin of the Arduino.
• RX pin connected to the D3 pin of the Arduino.

DFPlayer MINI

• VCC pin connected to the 5V output from the Arduino.
• GND pin connected to the common ground.
• TX pin connected to the D11 pin of the Arduino.
• RX pin connected to the D10 pin of the Arduino.
• SPK1 and SPK2 pins connected to the pin1 and pin2 of the Loudspeaker, respectively.

POWER SUPPLY 12V 5AMP

• GND (DC) pin connected to the GND IN of the DC DC converter.
• 12V-24V Output (DC) pin connected to the +VCC IN of the DC DC converter.

LCD screen 16x2 I2C

• VCC pin connected to the 5V output from the Arduino.
• GND pin connected to the common ground.
• SDA pin connected to the A4 pin of the Arduino.
• SCL pin connected to the A5 pin of the Arduino.

DC DC converter

• GND IN pin connected to the GND (DC) of the POWER SUPPLY.
• +VCC IN pin connected to the 12V-24V Output (DC) of the POWER SUPPLY.
• GND OUT pin connected to the common ground.
• +VCC OUT pin connected to the Vin pin of the Arduino.

Loudspeaker

• pin1 connected to the SPK1 of the DFPlayer MINI.
• pin2 connected to the SPK2 of the DFPlayer MINI.

Documented Code

#include <SoftwareSerial.h>
#include <TinyGPS++.h>
#include <DFRobotDFPlayerMini.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Pin definitions
const int gpsRxPin = 2;
const int gpsTxPin = 3;
const int dfPlayerRxPin = 10;
const int dfPlayerTxPin = 11;

// Create objects for GPS, DFPlayer, and LCD
TinyGPSPlus gps;
SoftwareSerial gpsSerial(gpsRxPin, gpsTxPin);
SoftwareSerial dfPlayerSerial(dfPlayerRxPin, dfPlayerTxPin);
DFRobotDFPlayerMini dfPlayer;
LiquidCrystal_I2C lcd(0x27, 16, 2); // Adjust the I2C address if necessary

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  gpsSerial.begin(9600);
  dfPlayerSerial.begin(9600);

  // Initialize DFPlayer
  if (!dfPlayer.begin(dfPlayerSerial)) {
    Serial.println("DFPlayer Mini not detected");
    while (true);
  }
  dfPlayer.volume(20); // Set volume level (0-30)

  // Initialize LCD
  lcd.begin();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Bus Stop System");

  // Initialize GPS
  Serial.println("Initializing GPS...");
}

void loop() {
  // Read GPS data
  while (gpsSerial.available() > 0) {
    gps.encode(gpsSerial.read());
  }

  // Check if GPS data is valid
  if (gps.location.isUpdated()) {
    double latitude = gps.location.lat();
    double longitude = gps.location.lng();

    // Display GPS data on LCD
    lcd.setCursor(0, 1);
    lcd.print("Lat: ");
    lcd.print(latitude, 6);
    lcd.setCursor(0, 2);
    lcd.print("Lon: ");
    lcd.print(longitude, 6);

    // Check if the bus is near a specific location (example coordinates)
    if (isNearBusStop(latitude, longitude)) {
      playAnnouncement();
    }
  }
}

bool isNearBusStop(double lat, double lon) {
  // Example bus stop coordinates
  const double busStopLat = 37.7749;
  const double busStopLon = -122.4194;
  const double threshold = 0.001; // Adjust the threshold as needed

  return (abs(lat - busStopLat) < threshold && abs(lon - busStopLon) < threshold);
}

void playAnnouncement() {
  dfPlayer.play(1); // Play the first audio file on the SD card
  delay(10000); // Wait for the announcement to finish
}

This code is responsible for initializing the GPS module, DFPlayer, and LCD screen. It reads GPS data, checks if the bus is near a predefined bus stop, and if so, plays an audio announcement while displaying the latitude and longitude on the LCD screen.