if your building it for the PC and PS3 you can still download C Libs for just about any microcontroller. I’m a big fan of AVR’s. this is the second time in two days I think I mentioned the teensy 2.0 and the teensy 2.0+ they are like $16 and $22. cheaper than most other pad hacks or PCB’s you could buy. it will take up all your time if you never wrote code in C or compiled or programmed a microcontroller. I would like to see more people on this forum doing their own microcontroller projects instead of it all being done by one person. there is a lot of information on the internet but I don’t want to jack this thread with a two page response.
as a side note to making your own turbo. there are many ways but here is another. when you have a common ground pad, that means that each input pin is connected to V+ through a resistor making the microcontroller see V+ at that input pin. when you press a button, you are pulling that pin to 0v (ground). since there is a resistor sitting between the input pin for that button and V+ but no resistor on the ground side, the microcontroller sees this 0v as a ON (button pressed). but in reality its being triggered when there is NO electricity flowing to that pin. if you want to make your own turbo you need to totally erase that pull up resistor so you can control whats going in to that pin of the microcontroller from yet another microcontroller. they connect pin for pin. output to input. just dont send 5v logic to a 3.3v microcontroller that might come stock in the pad you are hacking.
so how do you know what the voltage is??? easy, just look for 3.3v regulators in SMD. most things are USB power these days so that is 5v. other standards are 2.7v and 1.8v though I have not seen it in a pad yet since that is relatively new technolgy. not new but not popular till now. 1.8v is also lower than most batteries and can be subject to noise and interference at high speeds so I guess it makes sense.
here are some picture of real PCB’s with regulators of various sizes.
on this one its got 5 pins instead of 3. its sitting dead center below where it says “mini”. directly below that SMD resistor that has 2 pins and is way small.
so most regulators are 3 or 5 pins. sometimes the extra pins are just to hold it physically to the board and are either NC (no connection) or redundant with other pins. in the first example it is very easy to find it cause its big and it has a heat sink. in the second example they use one of the two designs that you see everywhere for small regulators.
there are other tricks like memorizing part numbers and looking up datasheets. LP2985 for example is part of a family that includes every LP29XX
I hope I’m not just dumping too much information on you. let me know if this is useful or not.