I have an external led (color is red) which flash with variable frequency. I need to monitor those flashes, calculating how many time led flash in a minute and log them.
I made a first try with an Arduino + photoresistor + LM358 as comparator (to get ON/OFF signal from photoresistor) and it works.
I use them because I have those components available to make a test, but now I need to create a very small circuit with very low power consumption and wireless connection.
- microcontroller: ESP8266-01
- VDD: 3.3V (coin battery)
- led frequency up to (about) 5Hz
What about the light sensor circuit? What is the best way to simplify it and keep consumption very low?
NOTE: I cannot open/modify the device I need to monitor. The only way to monitor its activity is through led activity