Using an Ardunio to count the number of blinks from the electricity meter in the flat and eventually convert that into live and historical electricity usage graphs.

It's a really simple circuit, basically connect the light dependent resitor (LDR) to the 5V pin on the Ardunio, then connect back to GND with a 100k resistor between the LDR and GND. Connect the analog data pin (A0) just after the LDR.

Then, upload some code to the Ardunio to count the number of blinks. You might need to tweak the delay and the sensorValue depending on your electric meter LED type. These values worked for me.