I guess you got my email.
Thanks for coming over and checking everything out.
I think that I have everything set up on my heliostat array exactly the way you said. It's working fairly well, but still not perfectly. I guess whatever is causing the drift has nothing to do with the fact that the mirrors on the left and right are angled since you are saying that it should work.
Something else must be messed up.
Right now, I think I'm just going to give up on trying to work out the bugs involved with linking the mirrors together and instead skip to controlling the mirrors separately, each with their own set of stepper motors. That way, I can change the targets for the mirrors via the software instead of having to go out and manually readjust them.
That's pretty much been my ultimate goal all along anyway.
My next goal is to see if its possible to control multiple heliostats with just a single two axis driver board. This should help bring down the cost of the electronics. Basically, what I want to do is to use MOSFETs to turn the different sets of stepper motors on and off when the computer tells them to.
So, if I had three heliostats, that would be three pairs of stepper motors controlled with just one 2-axis driver board.
If it's time to move heliostat #1, a MOSFET would be told by the computer to allow power to flow from the driver board to the first pair of stepper motors.
If it's time to move heliostat #2, a different MOSFET would be told by the computer to allow power to flow from the driver board to the second pair of stepper motors.
It would be the same process for heliostat #3 and I suppose several more heliostats if need be.
I don't know a whole lot about electronics, so there might be a flaw in my plan. That is my general idea though. Do you, or anybody else for that matter, know of any similar examples that someone else might have tried?
The one problem that I see with it so far is that several MOSFETs might accidentally turn on all at once allowing the current to flow through several pairs of stepper motors which would probably ruin the driver board. The easiest way that I can see for controlling the MOSFETs is through the computer's parallel port. The parallel port tends to have a mind of its own though, so it is quite probable that this behavior could be what ends up ruining the driver board. I guess there would need to be some sort of protection against this sort of thing built into the circuit.
Another idea I had would be to use an Arduino or another similar micro processor. The computer would first send the instructions to the Arduino via a serial connection and then the Arduino would be what actually controls the MOSFETs and driver board. That way, any random signals sent out by the computer, when it's turning off or on for example, won't have any effect on the heliostats.
The Arduino also has more outputs than a parallel port, which means that it would be possible to control more heliostats. If I do end up using one, I want to see if its possible to control the heliostats entirely with the Arduino. That way, I don't need to use a power hungry desktop or laptop all the time. I'd only need the computer if I wanted to change targets. It also should be pretty easy to set up a wireless connection with the Arduino so that I can reduce the number of wires that go out to the heliostats.
So yeah, I have ideas.
I haven't had much time to work on it over the last few days, so obviously I needed to vent off some of my thoughts. Any suggestions from anybody with ideas of their own would be welcome. I'm basically just making it up as I go along at this point because I haven't a clue what I'm doing.