Project 2

 Smart Access and Environment Monitoring System

Overview:

This project combines light sensing, RFID communication, and user input to build a smart access and environment monitoring system. The system adapts LED brightness to ambient light, identifies users via RFID, and toggles modes using a push button.

Objectives:

1. Identify users via RFID and display their status in the serial monitor.
2. Adjust LED brightness dynamically based on ambient light levels.
3. Use Red Pitaya to analyze I²C signals, light flicker, and button inputs.

Components:

Steps:

1. Circuit Assembly:

1. Connect the Photodiode:
• Anode to Arduino analog input (e.g., A0) with a 10 kΩ pull-up resistor.
• Cathode to GND.
2. Connect the RFID Module:
• VCC to Arduino 5V.
• GND to Arduino GND.
• SDA to Arduino A4.
• SCL to Arduino A5.
3. Connect the Push Button:
• One terminal to Arduino digital pin (e.g., pin 2) with a 10 kΩ pull-down resistor.
• The other terminal to 5V.
4. Connect the LED:
• One terminal to Arduino PWM pin (e.g., pin 9) through a 220 Ω resistor.
• The other terminal to GND.

2. Arduino Programming:

1. Write a program to integrate all functionalities:
Copy

#include <Adafruit_PN532.h>const int photoPin = A0;
const int buttonPin = 2;
const int ledPin = 9;
Adafruit_PN532 nfc(A4, A5);

void setup() {
    pinMode(buttonPin, INPUT);
    pinMode(ledPin, OUTPUT);
    Serial.begin(9600);
    nfc.begin();
}

void loop() {
    // RFID Identification
    uint8_t uid[7];
    uint8_t uidLength;
    if (nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength)) {
        Serial.print("UID: ");
        for (uint8_t i = 0; i < uidLength; i++) {
            Serial.print(uid[i], HEX);
            Serial.print(" ");
        }
        Serial.println();
    }

    // Light Sensing
    int lightLevel = analogRead(photoPin);
    int brightness = map(lightLevel, 0, 1023, 0, 255);
    analogWrite(ledPin, brightness);

    // Button Input
    if (digitalRead(buttonPin)) {
        Serial.println("Button Pressed: Manual Mode");
    } else {
        Serial.println("Automatic Mode");
    }

    delay(200);
}

3. Red Pitaya Signal Analysis:

1. Photodiode:
• Monitor light intensity changes and detect flicker.
2. I²C Signals:
• Analyze communication between Arduino and RFID module.
3. Push Button:
• Visualize the raw and debounced button signal.

Value:

1. Combines multiple functionalities into a cohesive system.
2. Demonstrates the use of light sensing, RFID, and user input in a smart application.
3. Red Pitaya enhances understanding of signal behavior for debugging and optimization.