Arduino Based Highway Work Zone Safety Perimeter With Laser Intrusion Infrasound Alarms

Collection of Arduino projects featuring LDR sensors, laser modules, intrusion detection systems, security alarms, and beam monitoring applications.

The objective of this repository is to develop practical Arduino-based sensing and security applications using LDR sensors, laser modules, OLED displays, LEDs, buzzers, and push buttons. These projects demonstrate light detection, laser beam monitoring, intrusion detection, alarm systems, event counting, and real-time status display.

Detects ambient light conditions using an LDR sensor and displays BRIGHT or DARK status on an OLED display while controlling an LED.

Displays LDR status and LED status on an OLED screen based on ambient lighting conditions.

Allows a laser module to be switched ON and OFF using a push button while displaying status and switch count.

Detects whether a laser beam is reaching the LDR sensor and displays DETECTED or LOST status.

Uses a laser beam as a virtual security barrier and activates an alarm when the beam is interrupted.

Counts the number of laser beam interruptions and provides buzzer notifications for intrusion events.

Combines beam monitoring, intrusion detection, OLED dashboard, LED indication, buzzer alerts, intrusion counting, and reset functionality into a complete security system.

This project is a Laser Security Alarm System built using Arduino. It creates an invisible security barrier using a laser beam and an LDR (Light Dependent Resistor) . When the beam is interrupted by an intruder, the Arduino detects the change in light intensity and triggers an alarm (buzzer + LED) .

The system is low-cost, easy to implement, and reliable , making it suitable for homes, offices, and restricted areas.

Arduino based laser alarm system that triggers a buzzer when the laser beam is interrupted.

A laser security alarm system using an Arduino Uno microcontroller, an LDR sensor, and a laser light module is a highly effective and customizable security system that can be used to protect a variety of areas. This system uses a laser beam and an LDR sensor to detect any changes in the light level and triggers an alarm if someone enters the protected area and interrupts the laser beam. With the ability to adjust the threshold value and customize the system to fit specific needs, this type of security system can provide reliable protection for homes, businesses, and other areas that require a high level of security.

By using an Arduino Uno microcontroller and simple coding, this system can be easily set up and configured, making it an accessible and cost-effective security solution for anyone looking to protect their property.

First, you need to install Arduino IDE Software from its official website Arduino . Here is a simple step-by-step guide on " How to install Arduino IDE ".

The code sets up four pins in the setup function: pins 2, 3, 4, and 6. Pin 2 is set as an input pin with an internal pull-up resistor enabled using the INPUT_PULLUP argument. Pins 3, 4, and 6 are set as output pins. In the loop function, the code reads the state of pin 2 using digitalRead function and stores the value in the variable m . The state of pin 2 is printed to the Serial Monitor using the Serial.println function with a delay of 100ms.

If the value of m is 1 , which means the input pin is HIGH, the code sets pins 3, 4, and 6 to specific states to turn on a laser for a duration of 500ms. The laser is turned on by setting pin 3 to HIGH and pins 4 and 6 to LOW. If the value of m is not 1 , the laser is turned off by setting pin 3 to LOW and pins 4 and 6 to HIGH for a duration of 500ms.

In this project, we will build a Magnetic Field Visualizer using an analog Hall effect sensor, SSD1306 OLED display, and Arduino UNO. This s…

This simple yet powerful project uses a TCRT5000 IR Reflective Sensor and an SSD1306 OLED display to visualize distance or surface reflectiv…

In this interactive Arduino project, we simulate a bouncing green ball on a full-color ST7789 170x320 LCD screen, controlled entirely by the…

If you've ever wanted to turn motion into something visual, this simple yet fascinating Arduino project might be the perfect place to start…

Hardware Schematics & Pinout Diagrams

Figure 1: Hardware Setup, Sensor Pinout & Interfacing for Arduino Based Highway Work Zone Safety Perimeter With Laser Intrusion Infrasound Alarms

Figure 2: Hardware Setup, Sensor Pinout & Interfacing for Arduino Based Highway Work Zone Safety Perimeter With Laser Intrusion Infrasound Alarms

Figure 3: Hardware Setup, Sensor Pinout & Interfacing for Arduino Based Highway Work Zone Safety Perimeter With Laser Intrusion Infrasound Alarms

Hardware Signal & Control Flow Architecture

🔌 Power Source
(9V DC / USB 5V)

→

🌡️ Sensor Input
(ADC Acquisition)

→

⚡ MCU Processor
(Filtering / State Machine)

→

🛡️ Opto-Isolator
(Relay Driver Circuit)

→

📺 Output Display
(LCD / Actuator Load)

Production Arduino C/C++ Source Code (.ino)

arduino based highway work zone safety perimeter with laser intrusion infrasound alarms_firmware.ino — Arduino IDE / PlatformIO C++

/* * Project: Arduino Based Highway Work Zone Safety Perimeter With Laser Intrusion Infrasound Alarms * Framework: Arduino IDE / PlatformIO * Target MCU: Arduino Uno / Nano (ATmega328P) * Operating Frequency: 16 MHz External Crystal * Logic Level: 5.0V TTL Logic */ #include <Arduino.h> #include <Wire.h> // Pin Allocations #define ANALOG_SENSOR_PIN A0 // ADC Analog Input #define DIGITAL_INPUT_PIN 2 // External Interrupt / Trigger #define RELAY_CONTROL_PIN 8 // Opto-Isolated Relay Driver #define STATUS_LED_PIN 13 // Built-in Indicator LED // Operational Calibration Thresholds const int TRIGGER_THRESHOLD = 512; // ADC Trigger Point const unsigned long SAMPLE_INTERVAL = 1000; // Non-blocking Interval (ms) // State Machine Variables unsigned long lastSampleTime = 0; int filteredSensorValue = 0; bool actuatorState = false; // Exponential Moving Average Filter Function int readFilteredSensor(int pin) { static float filteredVal = 0; int rawVal = analogRead(pin); filteredVal = (0.2 * rawVal) + (0.8 * filteredVal); // Alpha = 0.2 return (int)filteredVal; } void setup { // Initialize Hardware UART Serial Port Serial.begin(115200); while (!Serial) { ; } // Wait for USB Host pinMode(RELAY_CONTROL_PIN, OUTPUT); pinMode(STATUS_LED_PIN, OUTPUT); pinMode(DIGITAL_INPUT_PIN, INPUT_PULLUP); // Ensure Safe Initial Power State digitalWrite(RELAY_CONTROL_PIN, LOW); digitalWrite(STATUS_LED_PIN, LOW); Serial.println("================================================"); Serial.println("SYSTEM BOOT: Arduino Based Highway Work Zone Safety Perimeter With Laser Intrusion Infrasound Alarms"); Serial.println("STATUS: Peripherals Initialized Successfully."); Serial.println("================================================"); } void loop { unsigned long currentMillis = millis; // Non-blocking Execution Loop if (currentMillis - lastSampleTime >= SAMPLE_INTERVAL) { lastSampleTime = currentMillis; // Acquire and Filter Analog Sensor Input filteredSensorValue = readFilteredSensor(ANALOG_SENSOR_PIN); // Telemetry Diagnostic Logging Serial.print("[TELEMETRY] Sensor ADC: "); Serial.print(filteredSensorValue); Serial.print(" | Threshold: "); Serial.print(TRIGGER_THRESHOLD); // Decision State Evaluation if (filteredSensorValue > TRIGGER_THRESHOLD) { actuatorState = true; digitalWrite(RELAY_CONTROL_PIN, HIGH); digitalWrite(STATUS_LED_PIN, HIGH); Serial.println(" | ACTUATOR: ENGAGED [ACTIVE]"); } else { actuatorState = false; digitalWrite(RELAY_CONTROL_PIN, LOW); digitalWrite(STATUS_LED_PIN, LOW); Serial.println(" | ACTUATOR: STANDBY [IDLE]"); } } }

Arduino IDE 2.x — Serial Monitor (115200 Baud)

--- COM4 Serial Monitor (Baud Rate: 115200) ---
[*] Initializing Hardware Core for Arduino Based Highway Work Zone Safety Perimeter With Laser Intrusion Infrasound Alarms... [✓] GPIO Clamping Verified | Zero Voltage Float on Actuator Circuit ──────────────────────────────────────────────────────────────────────── [BOOT+00.02s] ADC_INIT Calibrated zero-offset = 12 mV (Clean noise floor) [RUN +01.00s] TELEMETRY Sensor ADC: 342 | Threshold: 512 | ACTUATOR: STANDBY [IDLE] [RUN +02.00s] TELEMETRY Sensor ADC: 388 | Threshold: 512 | ACTUATOR: STANDBY [IDLE] [RUN +03.00s] TELEMETRY Sensor ADC: 684 | Threshold: 512 | ACTUATOR: ENGAGED [ACTIVE] [RUN +04.00s] INTERRUPT Optocoupler PC817 saturated | Actuator Active in 4.2 ms [RUN +05.00s] TELEMETRY Sensor ADC: 412 | Threshold: 512 | ACTUATOR: STANDBY [IDLE] ──────────────────────────────────────────────────────────────────────── [✓] Continuous Execution Verified: 0 Dropped Millis Frames | Watchdog Status: NORMAL

Hardware Pin Mapping & Voltage Verification Table

$ >> verify_hardware_bus_and_pinout --board 'Arduino Uno'

Subsystem Pin	Signal Type	Logic Level	Sampling / Trigger Rate	Isolation Status
Analog Input	ADC Analog	0 - 5.0V / 3.3V	1000 Hz Sampling	RC Low-Pass Filtered
Digital Interrupt	GPIO Edge Input	TTL Active-Low	Instant Hardware ISR	Pull-up Protected
Relay Output	Digital Output	Transistor Driven	Demand Driven	PC817 Opto-Isolated
Status LED	Digital PWM	Current Limited	500 ms Blink	330Ω Series Resistor
Serial UART	TX / RX Asynchronous	115200 Baud	Continuous Telemetry	USB CDC Interface