Michael Beyhs has a new site called Electrical Engineering and More, his first project shows us how to Use an LED as a Sensor. LEDs are normally used to produce light but like many other electrical items it works a bit in the other direction, meaning that it will produce a small voltage when you shine light into it.
“How the code works:
- Configure all analog inputs to outputs and pull low to turn on all red LEDs.
- Turn one analog input pin into an actual Input and read the amount of light that is reflected into it.
- Turn that input back into an output and continue on to next.
- After all inputs have been read adjust the PWM of the blue LEDs according to the amount of light that was measured.
- loop forever…”