This question is not my normal type of question but here goes.
Today a friend of mine approached me about a car project he is working on. He wants to customize it and add all kinds of gadgets to the car. Specifically he wants an LCD monitor to come down out of the roof, he wants speech and speech recognition, as well as the ability to interface with the ECM and display real time engine data on the screen.
I told him this is not impossible, but it would take a lot of time and research.
Now Salem is probably one of the only ones who may be able to help me here. I can code any CPU as long as I download the data sheet. Heck most of them come with in-circuit debuggers, linkers, C compilers, and librarians. So I don't even have to do pure assembly...which wouldn't be that hard anyways given their limited instruction set. But building a board to interface with the CPU is not my field of expertise. I also advised my friend that if he wants speech, we would have to invest in a chip that had good addressing capability. The NEC 78K chip may not be able to address more than a couple meg of memory.
And for speech I would need an onboard DSP with an onboard DMA to stream the memory and use a chip that supported hardware and software interrupts as well as interrupt masking. I told him that he needs far more power here than your average CD player or coffee maker. We are talking about a mini-computer here.
Now once we get the board designed and up and running (and design a case for it that mounts to our car of choice) the rest is just coding, testing, and then burning the EPROM. That part I can do.
Any ideas as to where to begin with the circuit board design? I'm a software guy and although I understand how different IC's work and are used....I don't know how to stick them all on a board and get them to work together.
I think we will probably need at the least a 16-bit CPU capable of addressing 4 meg or more. The only other alternative is to store the speech data in compressed form such as MP3 and play it back. Also we need speech recognition which is probably just another IC with different functions and opcodes to query, get values, and execute speech recognition functions.
Putting this altogether on a board is more along the lines of electrical engineering more than software engineering.