Dan

I was unpleasantly surprised at the prices (and limited capabilities) of commercially-available dew controllers, and was already gathering parts for your focuser design, so this looks like another project for my list. But I'm confused about one thing--why is the circuit using a LM7808 to feed +8V into the Arduino, just for it to regulate it down to +5V and then serve as the source for all the other +5V loads? It seems to me (not an EE, nor do I play one on TV) that it would make more sense to use...