1. A switch to initiate the electrolysis which I could control from Arduino
2. A switch to initiate the peltier which I could control from Arduino
3. The ability to measure how heavy the peltier gets (to know how much condensation has formed on it)
Well, all this kind of depends on whether you're doing this on an industrial scale (with industrial explosive atmosphere considerations), or at the kitchen sink with some old coffee jars.
This depends upon the voltage and current of the electrolysis process. Or are you asking about how to do the actual electrolysis?
Same as above: what did you have in mind? My guess is that it's low-voltage high-current DC in which case a MOSFET would work, or a relay.
What kind of weight difference are you looking for? A change of a few grams, hundreds of grams?
This looks like a High School project and you want us to do your home work. That's fair enough -- some people love to help with those projects.
PS: Do you know how to be safe with hydrogen? Is this a supervised project? You do know about explosives -- right?
You do realize that you will supply more energy than you retrieve from the process -- right?
Terry what search criteria did you use?
As to the ice on the peltier you might look at an optical way to detrmine frost buildup
For switches you probably use logic level mosfets or solid state relays. There probably a lot of alternative methods for measuring humidity from a horse hair contraction/expansion to various electronics. As to the ice on the peltier you might look at an optical way to detrmine frost buildup. As to some of the other off the wall comments and concerns like "You do realize that you will supply more energy than you retrieve from the process -- right?", well, they mean well.
Can the Arduino perform such image analysis? I'm looking to make this totally Arduino based so a camera to a desktop is a bit of a no go. I am open to other ideas however.
Is there a manual for that FET switch? Or is it one of those things that are fairly standard to operate? If so is there a tutorial on this?