Ok! :-) I realize, and I thank you, that you are all very kind. As for now, I think I have really *a lot* to study, and to test. My (little) spare time will go to this project, and I will report the progress here. I would have a lot more questions, but it would not be fair to ask everything, and not try and test, so I'll keep silent, now, and will start with the components I already ordered. Thanks to anyone, I'll let you know everything! Bye Andrea

Thanks very much, Paul, this is by far *much* more than what I hoped for. But I still have many questions, and I don't even hope for a further answer from you! :-) First of all, I need to clarify, for what I've seen of the model: rail exchange is done with a three-way pulse button, that closes a 16V AC circuit (this looks very strange to me! why not DC???) in one of two directions: you give an impulse up, for example, and the rail goes right, you give an impulse down, and you get the rail going left. There is an electromagnet calling the rail in the two directions. So the first problem is just this: googling around, I saw many people saying to *NOT* use DC to AC relay control, because of some coil *induction* effect (I don't know what this is, but they say that voltage can go really up for a few moments). Can you confirm that (I suppose because of the very small power) I will not have this kind of problem? The problem with the lights is much simpler: they are all very small LEDs, so the only problem, I think, is to use some sort of bus just to not have that many wires going all around. Actually for each LED there are two wires going back to the central control panel, and I think they are at least one hundred! A first approach could even be to use some other NetDuino in calculated places, to control local groups of leds, but then I have the problem of 'speaking' from a NetDuino to another, even if I think I can find documentation on this. The last problem, that in the first post I didn't mention, is to control train movement. Actually, since there are five distinct groups of binaries, my friend has five power supplies, but of a type I didn't know about. In Italy we have 220V AC, so this is the input, but then there are two outputs: one is the 16V AC to drive rail exchange, and one is the DC current to move trains, that can be altered with a gauge. Rotating this, you can even invert positive and negative, I suppose, because trains on the rails invert direction, and go faster or slower according to the level of rotation: so I suppose that this is some kind of potentiometer that can invert Voltage. My last question, at this point, is: may I think to replace this power supply with 'something' (what can it be?) that I can then control with software with a NetDuino? Right now, if you want to simulate the train going in station, you have to manually slow it with the gauge, but it would be fantastic to have some software algorithm at the press of a button, that slows the train until it stops! Too many problems? All of this looks very interesting, to me, even only to learn NetDuino programming *AND* basic electronics control (I already have bought a couple of books!). I am obviously available to share on this community all the details and the lessons learned! Thanks again. Andrea

Hi to everybody. As a software programmer, I have a very small knowledge (and all theoretical!) about hardware at this level. So, my problem is: a friend of mine has a very large train model set (five groups of rails, 15 trains, 10 meters by 3), all handled in analogical (kilometers of wires! :-)). So I told him I could help, trying to use a netduino to handle all the problems, but now I realize I don't have the necessary experience. So, just to start, I focused the first two problems: - Rail exchange is handled by a 16V AC line: to move the rail in one of two positions, you have to close one of the two circuits (ground is common), and just with an impulse. Which kind of relay/transistor do I have to use? - Traffic lights, rail exchange, other lights: all need wires, and on a 10x3 meters set, there are a lot of them. I'm thinking to some sort of bus (I2C?) to minimize the number of wires, but then, again, which kind of solution may I imagine? Theoretically, I would like to have some sort of I/O controller with for example 16 pins, and being able to connect to it from a distance of 5 meters, or something like that; from there, I would have to use way less wires... Anyone so kind to give me at least the directions where to look for? Thanks in advance to anyone, and excuse my poor English... Andrea