ESP32 Energy Monitor with Power Meter

/*********************************************************************
 * ESP32 Energy Monitor with PZEM-004T
 * 
 * Measures: Voltage, Current, Power, Energy, Frequency
 * Hardware: ESP32, PZEM-004T V3.0, OLED Display
 * 
 * Libraries Required:
 * - PZEM004T (install from Library Manager)
 * - Adafruit GFX
 * - Adafruit SSD1306
 *********************************************************************/

#include 
#include 
#include 
#include 
#include 

// ============== PZEM CONFIGURATION ==============
#define PZEM_RX 16
#define PZEM_TX 17

PZEM004T pzem(&Serial2);
IPAddress ip(192, 168, 1, 1);

// ============== DISPLAY CONFIGURATION ==============
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// ============== WIFI ==============
const char* wifi_ssid = "YOUR_WIFI";
const char* wifi_password = "YOUR_PASSWORD";

// ============== THINGSPEAK ==============
String apiKey = "YOUR_THINGSPEAK_KEY";
String server = "http://api.thingspeak.com/update";

// ============== DATA STRUCTURE ==============
struct EnergyData {
  float voltage;
  float current;
  float power;
  float energy;
  float frequency;
  float pf;
};

EnergyData data;
unsigned long lastUpdate = 0;
const unsigned long UPDATE_INTERVAL = 5000;

void setup() {
  Serial.begin(115200);
  Serial.println(F("\n======================================"));
  Serial.println(F("ESP32 Energy Monitor Starting..."));
  Serial.println(F("======================================"));
  
  // Initialize PZEM
  pzem.setAddress(ip);
  
  // Initialize Display
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("Display allocation failed"));
  }
  display.display();
  delay(1000);
  
  // Connect WiFi
  connectToWiFi();
  
  Serial.println(F("Setup complete!"));
}

void loop() {
  if (millis() - lastUpdate > UPDATE_INTERVAL) {
    lastUpdate = millis();
    readPZEM();
    updateDisplay();
    sendToThingSpeak();
  }
}

void readPZEM() {
  // Read all values from PZEM
  data.voltage = pzem.voltage(ip);
  data.current = pzem.current(ip);
  data.power = pzem.power(ip);
  data.energy = pzem.energy(ip);
  data.frequency = pzem.frequency(ip);
  data.pf = pzem.pf(ip);
  
  // Print to Serial
  Serial.println(F("========== ENERGY DATA =========="));
  Serial.print(F("Voltage: ")); Serial.print(data.voltage); Serial.println(F(" V"));
  Serial.print(F("Current: ")); Serial.print(data.current); Serial.println(F(" A"));
  Serial.print(F("Power: ")); Serial.print(data.power); Serial.println(F(" W"));
  Serial.print(F("Energy: ")); Serial.print(data.energy); Serial.println(F(" kWh"));
  Serial.print(F("Frequency: ")); Serial.print(data.frequency); Serial.println(F(" Hz"));
  Serial.print(F("Power Factor: ")); Serial.println(data.pf);
  Serial.println(F("================================\n"));
}

void updateDisplay() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  
  display.setCursor(0, 0);
  display.println(F("ENERGY MONITOR"));
  display.drawLine(0, 10, 128, 10, SSD1306_WHITE);
  
  display.setCursor(0, 16);
  display.print(F("V: ")); display.print(data.voltage, 1); display.println(F(" V"));
  
  display.setCursor(0, 28);
  display.print(F("I: ")); display.print(data.current, 2); display.println(F(" A"));
  
  display.setCursor(0, 40);
  display.print(F("P: ")); display.print(data.power, 0); display.println(F(" W"));
  
  display.setCursor(0, 52);
  display.print(F("E: ")); display.print(data.energy, 3); display.println(F(" kWh"));
  
  display.display();
}

void sendToThingSpeak() {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = server + "?api_key=" + apiKey;
    url += "&field1=" + String(data.voltage);
    url += "&field2=" + String(data.current);
    url += "&field3=" + String(data.power);
    url += "&field4=" + String(data.energy);
    
    http.begin(url);
    http.GET();
    http.end();
  }
}

void connectToWiFi() {
  WiFi.begin(wifi_ssid, wifi_password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(F("."));
  }
  Serial.println(F(" Connected!"));
}