Circuit Documentation

Summary

The circuit is designed to monitor and control various parameters such as temperature, voltage, and current. It includes an Arduino Nano microcontroller interfaced with multiple sensors, a display module, pushbuttons, solid-state relays, MOSFETs, and other components. The system allows for setting thresholds and has features like alarm indication, automatic shutoff, and live monitoring displayed on an LCD.

Component List

• Arduino Nano: A compact microcontroller board based on the ATmega328P, featuring digital and analog I/O pins.
• Power 220V: The main power source for the circuit, providing 220V AC.
• LM2596: A DC-DC buck converter module used to step down voltage levels.
• Bridge Rectifier: Converts AC power from the main source to DC power.
• MKE-M08 LCD2004 I2C Module: An LCD display module with I2C communication for displaying system statuses and readings.
• Pushbuttons (x5): Used for user input to control the system and set thresholds.
• 2 Channel G3MB-202P Solid-State Relay: Allows for controlling high-power devices with low-power signals from the microcontroller.
• Voltage Sensors (x2): Measure the voltage in the circuit.
• IRFZ44N MOSFETs (x2): Power MOSFETs used for switching and controlling power to the loads.
• ACS712 Current Sensors (x2): Measure the current flowing through the circuit.
• Sockets (x2): Interface for connecting external devices to the circuit.
• NTCs (x2): Thermistors used for measuring temperature.
• RGB LED: An LED that can display multiple colors based on the input signals.
• Resistors: Various resistors used for current limiting and voltage division.
• Piezo Buzzer: An audible alarm device for alerting when thresholds are exceeded.
• Grounding Receptacle Outlet 15A 250V~: Provides a grounding connection for the circuit.
• Electrolytic Capacitor: Used for filtering and stabilizing the DC power supply.

Wiring Details

Arduino Nano

• GND: Connected to the ground plane of the circuit.
• D2-D10: Connected to pushbuttons and relay control.
• D11/MOSI, D12/MISO: Control signals for the RGB LED and MOSFETs.
• A0-A5: Analog inputs connected to NTCs, voltage sensors, and current sensors.
• 5V: Powers the LCD module, solid-state relay, voltage sensors, and current sensors.
• VIN: Receives power from the LM2596 buck converter.

Power 220V

• Hot Wire: Connected to the solid-state relay and bridge rectifier.
• Neutral Wire: Connected to the grounding receptacle outlet and sockets.

LM2596

• IN: Connected to the bridge rectifier.
• OUT: Provides regulated voltage to the Arduino Nano and other 5V components.

Bridge Rectifier

• Source_in-/+: Connected to the power 220V and grounding receptacle outlet.
• Source_out-/+: Connected to the LM2596 and grounding receptacle outlet.

MKE-M08 LCD2004 I2C Module

• GND, 5V: Power connections.
• SDA, SCL: I2C communication lines connected to the Arduino Nano.

Pushbuttons

• Pin 2: Common ground connection.
• Pin 4: Connected to the Arduino Nano digital pins with pull-up resistors.

2 Channel G3MB-202P Solid-State Relay

• DC+/-: Control input from the Arduino Nano.
• Signal Trigger 1/2: Control signals from the Arduino Nano.
• AC Hot Wire/Neutral Wire: Connected to the power 220V and voltage sensors.

Voltage Sensors

• Ground, Vcc: Power connections.
• Phase: Connected to the solid-state relay.
• Out: Analog output connected to the Arduino Nano.

IRFZ44N MOSFETs

• Gate: Control signal from the Arduino Nano.
• Drain: Connected to the sockets.
• Source: Common ground connection.

ACS712 Current Sensors

• GND, VCC: Power connections.
• OUT: Analog output connected to the Arduino Nano.
• 1, 2: Connected to the voltage sensor and socket.

Sockets

• Earth: Connected to the grounding receptacle outlet.
• Life/Neutral: Connected to the solid-state relay and current sensors.

NTCs

• A0, A1: Connected to the Arduino Nano and resistors.

RGB LED

• R, G, B: Control signals from the Arduino Nano through resistors.
• COM: Common ground connection.

Resistors

• Pin 1/2: Connected between various components and the Arduino Nano for current limiting and voltage division.

Piezo Buzzer

• Pin 1/2: Connected to the Arduino Nano for audible alerts.

Grounding Receptacle Outlet 15A 250V~

• Life/GND: Connected to the bridge rectifier and power 220V.

Electrolytic Capacitor

• +/-: Connected to the Arduino Nano for power filtering.

Documented Code

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Pin definitions
#define BUTTON_1_PIN 6
#define BUTTON_2_PIN 7
#define BUTTON_3_PIN 8
#define BUTTON_4_PIN 9
#define BUTTON_5_PIN 10

#define RELAY_PIN 3
#define BUZZER_PIN 5
#define MOSFET_PIN 4
#define MOSFET_PIN_2 12

#define RGB_RED_PIN 11
#define RGB_GREEN_PIN 10
#define RGB_BLUE_PIN 9

// LCD initialization
LiquidCrystal_I2C lcd(0x27, 20, 4);

// Threshold variables
float tempThreshold1 = 50.0;
float voltageThreshold1 = 240.0;
float currentThreshold1 = 5.0;

float tempThreshold2 = 50.0;
float voltageThreshold2 = 240.0;
float currentThreshold2 = 5.0;

// Desired current levels
float desiredCurrent1 = 2.0;
float desiredCurrent2 = 2.0;

// Sensor readings
float temperature1 = 0.0;
float voltage1 = 0.0;
float current1 = 0.0;

float temperature2 = 0.0;
float voltage2 = 0.0;
float current2 = 0.0;

bool isSetMode = false;
bool isAlarmOn = false;
bool isAutoShutOff = false;
bool isSystemOn = true;

enum ThresholdType { TEMPERATURE, VOLTAGE, CURRENT, CURRENT_SET1, CURRENT_SET2 };
ThresholdType selectedThreshold = TEMPERATURE;

unsigned long lastThresholdChangeTime = 0;
bool thresholdChanged = false;

unsigned long lastButton5PressTime = 0;
unsigned long button5PressCount = 0;
unsigned long alarmStartTime = 0;

void setup() {
    Serial.begin(9600);

    lcd.init();
    lcd.backlight();

    // Pin mode configuration
    pinMode(RELAY_PIN, OUTPUT);
    pinMode(BUZZER_PIN, OUTPUT);
    pinMode(MOSFET_PIN, OUTPUT);
    pinMode(MOSFET_PIN_2, OUTPUT);
    pinMode(BUTTON_1_PIN, INPUT_PULLUP);
    pinMode(BUTTON_2_PIN, INPUT_PULLUP);
    pinMode(BUTTON_3_PIN, INPUT_PULLUP);
    pinMode(BUTTON_4_PIN, INPUT_PULLUP);
    pinMode(BUTTON_5_PIN, INPUT_PULLUP);

    pinMode(RGB_RED_PIN, OUTPUT);
    pinMode(RGB_GREEN_PIN, OUTPUT);
    pinMode(RGB_BLUE_PIN, OUTPUT);

    // Initial state of outputs
    digitalWrite(RELAY_PIN, LOW);
    digitalWrite(BUZZER_PIN, LOW);
    analogWrite(MOSFET_PIN, 0);
    analogWrite(MOSFET_PIN_2, 0);

    setRGBColor(0, 0, 255); // Set initial color to blue (Set Mode)
}

void loop() {
    // Button handling
    if (digitalRead(BUTTON_4_PIN) == LOW) {
        isSetMode = !isSetMode;
        delay(200); // Debounce delay
    }

    if (digitalRead(BUTTON_1_PIN) == LOW) {
        increaseThreshold();
        delay(200); // Debounce delay
    }

    if (digitalRead(BUTTON_2_PIN) == LOW) {
        decreaseThreshold();
        delay(200); // Debounce delay
    }

    if (digitalRead(BUTTON_3_PIN) == LOW) {
        switchThresholdType();
        delay(200); // Debounce delay
    }

    if (digitalRead(BUTTON_5_PIN) == LOW) {
        handleButton5Press();
        delay(200); // Debounce delay
    }

    // Mode handling
    if (isSetMode) {
        setRGBColor(0, 0, 255); // Blue for Set Mode
        displaySetMode();
    } else {
        // Read sensors
        temperature1 = readTemperature(A0);
        voltage1 = readVoltage(A1);
        current1 = readCurrent(A2