Off the shelf controller chipset or PCB?

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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.


Re: Off the shelf controller chipset or PCB?

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and

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

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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.

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

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Re: Off the shelf controller chipset or PCB?

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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)?

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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.


Re: Off the shelf controller chipset or PCB?
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



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Re: Off the shelf controller chipset or PCB?
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.


Re: Off the shelf controller chipset or PCB?

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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.


Re: Off the shelf controller chipset or PCB?
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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.

--
Luhan Monat: luhanis(at)yahoo(dot)com
http://members.cox.net/berniekm
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Re: Off the shelf controller chipset or PCB?



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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



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