Instructions: https://github.com/n8kowald/powerpi
My flat has a prepayment energy meter.
Sometimes I forget to check how much money we have and the power goes out, forcing me to walk to the nearest open PayPoint location at inconvenient times.
I wanted a way to automate these checks.
![](https://www.nathankowald.com/blog/wp-content/uploads/2017/05/powerpi.jpg)
The Raspberry Pi B+ enclosed emails me a photo of the money we have left
I had an unused Raspberry Pi B+, camera module (REV 1.3), and a USB Wi-Fi dongle. With these I could take a photo of the amount left and email myself a photo every day at a specified time.
It turned out to be easy.
The most time consuming bit was experimenting with raspistill options to produce the best photo for the dark cabinet it’s enclosed in.
![Amount of money left on our prepaid electricity meter](https://www.nathankowald.com/blog/wp-content/uploads/2017/05/power-left-1.jpg)
Amount of money left on our prepaid electricity meter
As you can see the photo is not amazing. However, considering it was taken in a dark cabinet I’m happy with the result.
Full instructions here: https://github.com/n8kowald/powerpi
Next, I want to use Optical Character Recognition (OCR) to detect the amount in the photo.
I could then take readings every 5 minutes, save that to a database and produce a graph of the times when we use the most electricity.
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