Energy Meter Pulse Counter

thingiverse

DIN rail box and sensor case for the pulse counter for energy meter. Box and sensor case printed from PETG, any standard profile will be good enough. DIN clips are glued to the case. Device is designed to count the LED pulses from the standard home energy meter and store measured values online on Thinkspeak.com. You can monitor the actual power consuption or some defined intervals. Depending on the energy meter, one blink of the LED correspond to some power consumtion (the ratio is usually shown on the meter). By putting a photo transistor to the LED you can simply measure the blink counts and send those value to your preffered server or cloud. I am using the Thinkspeak.com server as it easy allows to create charts and has simple API. For anyone interested the circuit schema in Fritzing including PCB attached. Also attached Arduino IDE code for the controller. Controller used is ESP32 because it is dual core. The application is wrote for two cores because of need of uninterupted measuring every couple of ms. So one core takes care of pulse measurement in real-time, second core takes care about the data transmittion and other time consuming operations. Controller integrates ArduinoOTA, so once programmed can be reprogrammed over wifi without USB connection. Used HW: ESP-32S Development Board ESP-WROOM-32, 30 pin HLK-PM-01 240VAC/5VDC power supply Resistor 10kOhm Schottky diode 1N5819 Photo transistor THT 3mm SFH309-5 35V 860nm 2x 2-pole srew terminal 5mm 470uF 16V capacitor any two wire cable for the sensor (photo transistor) Attention: Used power supply's input voltage is 230VAC, that is not safe voltage and should be handled only by the professionals. The PCB is not safe for manipulation under voltage. Consider using external power adapter instead. This is on your own risk. Similar devices are available on the market, but the price is arround $200 and requires special readers to get the data back. Installation does not require any impact to the energy meter, you simple use sticky tape to fix the sensor to the LED on the energy meter. The measurement is very accurate, after 6 months of measurement I was not able to see any difference in measured kWh between my data and the numbers on the energy meter. As the data are stored on server once per minute, the immediate consumption in watts is in fact a minute average. But even that is fine to see, how much your electric devices really takes. Hope it helps.