Circuit Documentation

Summary

The circuit is designed to interface an Arduino UNO with a variety of components including a Neo 6M GPS Module, a SIM800L GSM module, a DC motor with a speed controller, and multiple LEDs and a buzzer for signaling purposes. The Arduino UNO is the central processing unit, controlling the motor's operation, receiving GPS data, and communicating via GSM. The circuit is powered by a 12V 200Ah battery, and a rocker switch is used to control the power supply to the motor driver. The DC motor's speed is regulated by a PWM speed controller, and the L298N motor driver interfaces the motor with the Arduino.

Component List

• Arduino UNO: A microcontroller board based on the ATmega328P, with digital and analog I/O pins.
• 12V 200Ah Battery: Provides the power source for the circuit.
• DC 12V PWM Speed Controller: Controls the speed of the DC motor using PWM signals.
• SIM800L: A GSM/GPRS module for cellular communication.
• Neo 6M GPS Module: A GPS receiver module for obtaining geographic location data.
• LED (Red): Three red LEDs used for signaling.
• Buzzer: An audible signaling device.
• DC Motor: An electric motor powered by the DC supply.
• Rocker Switch: A switch to control the power flow to the motor driver.
• L298N DC Motor Driver: A dual H-bridge motor driver for controlling the direction and speed of the motor.

Wiring Details

Arduino UNO

• 3.3V to Neo 6M GPS Module VCC
• 5V to SIM800L VCC
• GND to Neo 6M GPS Module GND, SIM800L GND, Buzzer GND, and all LED anodes
• Vin to L298N Motor Driver 5V
• D12 to Neo 6M GPS Module RX
• D10 to L298N Motor Driver ENA
• D9 to L298N Motor Driver IN1
• D8 to L298N Motor Driver IN2
• D7 to SIM800L RXD
• D6 to SIM800L TXD
• D5 to Buzzer PIN
• D4 to LED cathodes (shared by two LEDs)
• D3 to LED cathode
• D2 to Neo 6M GPS Module TX

12V 200Ah Battery

• GND to Arduino UNO GND, L298N Motor Driver GND
• 12V to Rocker Switch input

DC 12V PWM Speed Controller

• + to L298N Motor Driver OUT4
• - to L298N Motor Driver OUT3
• - Output to DC Motor pin 2
• + Output to DC Motor pin 1

Neo 6M GPS Module

• GND to Arduino UNO GND
• TX to Arduino UNO D2
• RX to Arduino UNO D12
• VCC to Arduino UNO 3.3V

SIM800L

• GND to Arduino UNO GND
• VCC to Arduino UNO 5V
• RXD to Arduino UNO D7
• TXD to Arduino UNO D6

LEDs (Red)

• Anode to Arduino UNO GND
• Cathode to Arduino UNO D3 (one LED), D4 (two LEDs)

Buzzer

• PIN to Arduino UNO D5
• GND to Arduino UNO GND

DC Motor

• Pin 1 to DC 12V PWM Speed Controller + Output
• Pin 2 to DC 12V PWM Speed Controller - Output

Rocker Switch

• Input to L298N Motor Driver 12V
• Output to 12V 200Ah Battery 12V

L298N DC Motor Driver

• GND to Arduino UNO GND
• 5V to Arduino UNO Vin
• 12V to Rocker Switch output
• ENA to Arduino UNO D10
• IN1 to Arduino UNO D9
• IN2 to Arduino UNO D8
• OUT3 to DC 12V PWM Speed Controller -
• OUT4 to DC 12V PWM Speed Controller +

Documented Code

#include <SoftwareSerial.h>
#include <TinyGPS++.h>

SoftwareSerial gsmSerial(6, 7);  // TX for GSM, RX for GSM
SoftwareSerial neo(2, 12);       // TX for GPS, RX for GPS
TinyGPSPlus gps;

// Motor and LED pins
int led1 = 11;
int led2 = 3;
int led3 = 4;
int led4 = 5;
int motorEN = 10;
int motorIN1 = 9;
int motorIN2 = 8;

String textMessage = "";
String lati = "";
String longi = "";

// Variables for non-blocking blinking
unsigned long lastBlinkTime = 0;
bool isBlinking = false;

void setup() {
  Serial.begin(9600);
  gsmSerial.begin(9600);
  delay(5000);
  Serial.println("Initializing GSM...");
  gsmSerial.println("AT");
  checkGSMResponse();
  gsmSerial.println("AT+CMGF=1");
  checkGSMResponse();
  gsmSerial.println("AT+CNMI=2,2,0,0,0");
  checkGSMResponse();
  
  neo.begin(9600);

  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(motorEN, OUTPUT);
  pinMode(motorIN1, OUTPUT);
  pinMode(motorIN2, OUTPUT);

  analogWrite(motorEN, 0);
  digitalWrite(motorIN1, LOW);
  digitalWrite(motorIN2, LOW);
  Serial.println("System initialized.");
}

void loop() {
  gsmSerial.listen();
  delay(2);

  if (gsmSerial.available() > 0) {
    textMessage = gsmSerial.readString();
    textMessage.trim();
    Serial.println("Received message: " + textMessage);
    
    if (textMessage.indexOf("ON") != -1) {
      handleOnMessage();
    } else if (textMessage.indexOf("OFF") != -1) {
      handleOffMessage();
    } else if (textMessage.indexOf("GETLOC") != -1) {
      handleGetLocMessage();
    }
    textMessage = "";
  }

  blinkLeds34Continuously();
}

void handleOnMessage() {
  Serial.println("Executing ON command");
  digitalWrite(led1, HIGH);
  digitalWrite(motorIN1, HIGH);
  digitalWrite(motorIN2, LOW);
  analogWrite(motorEN, 255);
  stopBlinkingLeds34();
}

void handleOffMessage() {
  Serial.println("Executing OFF command");
  digitalWrite(led1, LOW);
  blinkLED2();
  reduceMotorSpeed();
  startBlinkingLeds34();
}

void blinkLED2() {
  for (int i = 0; i < 5; i++) {
    digitalWrite(led2, HIGH);
    delay(300);
    digitalWrite(led2, LOW);
    delay(300);
  }
}

void reduceMotorSpeed() {
  int reductionDelay = 100;
  int steps = 255 / (10000 / reductionDelay);
  for (int speed = 255; speed >= 0; speed -= steps) {
    analogWrite(motorEN, speed);
    delay(reductionDelay);
  }
  analogWrite(motorEN, 0);
}

void blinkLeds34Continuously() {
  if (!isBlinking) return;

  unsigned long currentMillis = millis();
  if (currentMillis - lastBlinkTime >= 100) {
    lastBlinkTime = currentMillis;
    digitalWrite(led3, !digitalRead(led3));
    digitalWrite(led4, !digitalRead(led4));
  }
}

void startBlinkingLeds34() {
  isBlinking = true;
  lastBlinkTime = millis();
}

void stopBlinkingLeds34() {
  isBlinking = false;
  digitalWrite(led3, LOW);
  digitalWrite(led4, LOW);
}

void handleGetLocMessage() {
  Serial.println("Executing GETLOC command");
  neo.listen();
  smartDelay(1000);
  sendLocationSMS();
}

void sendLocationSMS() {
  gsmSerial.println("AT+CMGS=\"+250728418241\"");
  delay(500);
  String pesan = "https://maps.google.com/?q=" + lati + "," + longi;
  gsmSerial.print(pesan);
  gsmSerial.write(0x1a);
  delay(1000);
  gsmSerial.println("AT+CMGD=1,4");
  Serial.println("Location sent: " + pesan);
}

static void smartDelay(unsigned long ms)