As it turns out, sunlight is actually pretty important for plant growth. Who knew? Right? Well, it is important and if plants need it, I want to measure and log it as part of my Garden Project. To sense light, I'm simply using some photo resistors from Radio Shack. They come in a 5 pack I think, bunch of different sizes, but they all work exactly the same way. They are super simple components, but can be kinda tricky to get meaningful information out of. We need to add an additional component and do some math. I hate math.