In my last post, I spoke about creating a light sensing “widget” that I could attach to my projects. I used a 10k resistor and was reading the light readings off of the analog pin on Arduino. However, I noticed that attaching an LED to the circuit was throwing the readings way off.
so, I found another way of calculating brightness. I found this article which talked about using a capacitor attached to the photocell which is in turned attached to a digital pin on Arduino. I was able to attach an LED without throwing off my readings a lot. While I was making these modifications, I also decided to make some other improvements (like getting an LED holder to hold my power indicator)
Here’s a pic:
If you guys are looking for an informative tutorial on how to use a photocell, I found this article very helpful: http://learn.adafruit.com/photocells/using-a-photocell