PowerMeter/power_meter.ino

#include <EmonLib.h>
#include <ESP8266WiFi.h>
#include <PubSubClient.h>

#define TOPIC "/home/sensors/power"
#define MQTT_SERVER "192.168.1.3"
#define SSID "GCHQ Surveillance Van"
#define PASSWORD "cocklol."

#define MAINS_VOLTAGE 230.0
#define CALIBRATION 90.9090909091

void callback(char *topic, byte *payload, unsigned int length);

EnergyMonitor emon1;
WiFiClient wifiClient;
PubSubClient mqtt(MQTT_SERVER, 1883, callback, wifiClient);

void callback(char *topic, byte *payload, unsigned int length) {}

void waitForWiFi() {
	if (WiFi.status() == WL_CONNECTED)
		return;
	Serial.println("Reconnecting WiFi...");
	int waitCount=0;
	while (WiFi.status() != WL_CONNECTED) {
		delay(100);
		waitCount++;
		if (waitCount>600)
			ESP.restart();
	}
	Serial.println("Connected WiFi!");
}

void waitForMQTT() {
	if (mqtt.connected())
		return;
	Serial.println("Reconnecting MQTT...");
	while (!mqtt.connected())
		if (!mqtt.connect(TOPIC))
			delay(50);
	Serial.println("Connected MQTT!");
}

void reconnect() {
	waitForWiFi();
	waitForMQTT();
}

void setup() {
	Serial.begin(115200);

	WiFi.begin(SSID, PASSWORD);
	reconnect();

	emon1.current(A0, CALIBRATION);
}

void loop() {
	long startTick = millis();
	double Irms = emon1.calcIrms(1480);
	double kwh = Irms * MAINS_VOLTAGE;
	Serial.println(kwh);
	mqtt.publish(TOPIC, String(kwh).c_str());
	mqtt.loop();
	delay(10000 - (millis() - startTick));
}