#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <PZEM004Tv30.h>

#define OLED_RESET     -1
Adafruit_SSD1306 display(OLED_RESET);

#define relayPin 5 // Adjust according to relay module connection
#define increaseButton 9
#define decreaseButton 8
#define powerOffButton 7

PZEM004Tv30 pzem(10, 11); // RX, TX pins

float currentLimit = 10.0; // Initial current limit
bool isOn = true; // Initial state of the circuit

void setup() {
  pinMode(relayPin, OUTPUT);
  pinMode(increaseButton, INPUT_PULLUP);
  pinMode(decreaseButton, INPUT_PULLUP);
  pinMode(powerOffButton, INPUT_PULLUP);

  Serial.begin(9600);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }

  display.display();
  delay(1000);
  display.clearDisplay();
}

void loop() {
  // Read values from PZEM-004T module
  float current = pzem.current();
  float voltage = pzem.voltage();
  float power = pzem.power();
  float pf = pzem.pf();
  
  if (digitalRead(increaseButton) == LOW) {
    if (currentLimit < 40.0) {
      currentLimit += 1.0;
    }
    delay(100); // debounce
  }

  if (digitalRead(decreaseButton) == LOW) {
    if (currentLimit > 1.0) {
      currentLimit -= 1.0;
    }
    delay(100); // debounce
  }

  if (digitalRead(powerOffButton) == LOW) {
    isOn = !isOn;
    digitalWrite(relayPin, isOn);
    delay(100); // debounce
  }

  if (isOn) {
   
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0,0);
    display.print("Limit: ");
    display.print(currentLimit);
    display.println(" A");

    display.print("Current: ");
    display.print(current);
    display.println(" A");

    display.print("Voltage: ");
    display.print(voltage);
    display.println(" V");

    display.print("Power: ");
    display.print(power);
    display.println(" W");

    display.print("PF: ");
    display.println(pf);

    display.display();
  } else {
    display.clearDisplay();
    display.setTextSize(4);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(2,2);
    display.print("OFF");
    display.display();
  }
  // check for overload
  if ( current > currentLimit) {
    digitalWrite(relayPin, LOW); // Turn off the relay
    display.clearDisplay();
    display.setTextSize(3);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(2,2);
    display.print("OVER LOADED");
    display.display();
  }
}