Off the shelf controller chipset or PCB?

Hi,

I'm working on a control panel-like device that has a bunch of on/off buttons (100-200), a control knob (that drives an optical encoder) and an LCD display. The controller will interface with and control some software running on a PC via USB or CAT-5 or something similar.

Does anyone know of some standard or off the shelf PCB/chipset solution for such a controller? It seems like a relatively simple design in terms of signal complexity and routing; just a bunch of digital IO's plus a counter or two, in addition to a chip to drive the LCD, all interfacing with a programmable CPU.

What kind of processor will I need? Memory? The LCD chips? I've never done this sort of design before, and perhaps have a superficial understanding of what's involved. Once I have the PCB built, I feel this will be mainly a programming project.

Is there a firm that specializes in this kind of glorified 'remote control' PCB/chipset design? Do turnkey solution exist for this application?

Thank you for any advice you can provide. It is much appreciated.

R.G.

Reply to
R.G.
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and

It would be difficult to find a controller chip with 100s of I/O.

solution

The easiest way to do it is to use several CPLD programmed as parallel loaded shift registers. The controller chip enables loading 100s of inputs and shift in the data. A simple microcontroller can easily do the job, as well as driving an LCD.

How big and what types of LCD? Dumb or smart LCD?

Reply to
linnix

parallel

OK. I apologize, but I'm not too familiar with this stuff, so I'm a bit unclear. How would the controller and my many IO's be connected to the shift registers? When a button is pressed, what exactly will happen in the shift register, and what will my controller read (and where)?

My LCD would be at most 320x240 pixels and be programmable, so hopefully I can use graphics libraries to display data sent back from the PC.

I hope this helps. Thanks again.

Reply to
R.G.

are your switches toggle action or simply push button type actuation?

Is more than a couple of buttons going to be operated at any one time?

If they are simply pushbuttons and don't have many simultaneous operations it is possible to connect them in a matrix and scan them, maybe 15 x 15.

Phil

Reply to
Phil W

Many are toggle, but there are also many that are pushbutton action (i.e. something happens after a quick press and release). Some of the pushbutton action switches will be used together to invoke special functions, like a Shift or Alt key.

Reply to
R.G.

the

Perhaps you can use a combination of scanned matrix and true registered input. Shift and Alt types needed to be registered, but action keys does not. Another question is whether the state of your switch board need to be preserved during power cycles. If so, scanned matrix won't work.

Reply to
linnix

Almost Anything 8 to 32 bits. If you are only building 1 and do not want to make boards go big with a PC104 set up or an industrial PLC. If you want to build a PCB smaller CPUs are OK. You can Poll Shift Registers or latches. If you want to use a matrix you will need diodes so you can read all possibilities. TCP/IP or USB find something that inclues it, or it is a lot of work. You can use a n RS232 to USB chip (FDTI or SiLabs) to avoid and work on it.

Good Luck

Reply to
Neil Kurzman

Yea, a $10 keyboard for a PC plugged into a micro controller which drives a standard LCD module. 2 lines needed for keyboard, 6 lines for LCD. Quadrature encoder uses 2 more lines. 1 line to transmit serial data. PIC16F628 should do the trick. If you need a few more lines for other stuff, use the PIC16F870. Both have hardware UART function.

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