First of all, you have to prepare your DIY project. For that, you need to write down as many details as you can about your finished product. What do you want your blinds to do? Do you only need remote operation, or you want light sensors, or maybe timers, to have them moving at the same hour every day? If you’re away many hours a day, you may want your plants to benefit from light in the morning, but be protected in the afternoon, when the sun is too hot and might damage their leaves. Here’s a nice tutorial on how to build a motorized controller for your blinds. You can do it too, if you buy all those timers, interfaces, sensors and controllers. They come together in packs. An example is the PICAXE 08M Starter Pack, which includes all needed items and which costs $12.95.

This video shows the project in enough details so you can make yourself an idea of what you’re going to obtain.