powerMeter-ESP8266

Non-invasive power meter with ESP8266

Steps

You should have a PHP and PostgreSQL server on hand.

Circuit

Bought a Jack female connector, and solder all it to a breadboard, and put on the bottom of the ESP8266 as a shield.

Modifications

• With SCT-013-030, which has a burden resistor already, so I doesn't use any.
• Use the 3.3V voltage from the 8266, not the 5V!

Source: openenergymonitor.org

Calibration

The measurements were not accurate. I used a clamp meter and various devices (notebook charger, hair dryer, kettle to create a dataset, then I fitted the actual values with wolframalpha.com. This is probably the most complicated way, you can do it otherwise. It worked me.

Code for the ESP8266

You can find the code in powerMeter.ino

Creating database tables

CREATE TABLE "logger" (
	"id" INTEGER NOT NULL DEFAULT 'nextval(''logger_id_seq''::regclass)',
	"timestamp" TIMESTAMP NULL DEFAULT NULL,
	"amp" DOUBLE PRECISION NULL DEFAULT NULL,
	PRIMARY KEY ("id")
);
CREATE TABLE "price" (
	"price" INTEGER NULL DEFAULT NULL
);
UPDATE price SET price = 1.2;

CREATE VIEW "watt" AS  SELECT logger.id,
    (logger."timestamp" + '02:00:00'::interval) AS "timestamp",
    logger.amp,
    round((logger.amp * (VOLTAGE_IN_YOUR_COUNTRY)::double precision)) AS watt
   FROM logger
  ORDER BY logger.id DESC; ;
  
  
CREATE VIEW "daily_usage" AS  SELECT (date_trunc('day', watt."timestamp"))::date AS date_,
    round((avg(watt.watt) * (((count(date_trunc('hour', watt."timestamp")) / 60) + 1)))) AS watt,
    round((((avg(watt.watt) * (((count(date_trunc('hour', watt."timestamp")) / 60) + 1))) / (1000)) * (( SELECT price.price
           FROM price)))) AS price,
    (round((avg(watt.watt) * (((count(date_trunc('hour', watt."timestamp")) / 60) + 1)))) / (1000)) AS kw
   FROM watt
  GROUP BY ((date_trunc('day', watt."timestamp"))::date)
  ORDER BY ((date_trunc('day', watt."timestamp"))::date);