Project Description

Project isn’t finished yet but I have now built a device to count the flashes from my meter (each one of which represents 1Wh being imported) and log them into a web-based database.

I’ve managed to construct a prototype using a photoresistor, an Arduino microprocessor board and an Arduino Ethernet shield.

Command sent to internet is of form :-

(relevent url)?input=123450D

where the numbers show the number of flashes counted since the Arduino programme was last started and the suffix letter tells the webpage what to do with it. At the moment, I’m only sending Import Meter readings to the webpage and am deciding within the webpage script whether they represent day rate imports or night rate ones. Next stage will be to supply a signal to Arduino input pin when E7 circuits are live and let Arduino script append a letter ‘N’ when that signal is seen or a ‘D’ when it’s not.

To reduce internet traffic, rather than telling the webpage about every single flash, I’m only sending output on every tenth flash.


Next stage is to measure my export meter output in a similar manner – initially I’ll use a separate board for each meter but should eventually be able to do both on the same one. Meanwhile, I can of course export my inverter readings manually for analysing historic data although that’s not a lot of help for ‘instant’ results.

And of course when I have database fully up to date with imports, generation (and perhaps even exports) I can run other website scripts to process that output and show results on screen. Indeed, since it’s a web-based project I could theoretically use a smartphone to see how the electricity generation and consumption are doing whilst I’m on holiday.


For more information such as source and project, please refer to the following links.

Project :

Source :