[?] Displaying 16 analogue voltages (Graphic equaliser display style)

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"Graphic LCD modules"

I suspect the only practical way to do this for this many units involves a general-purpose display, a microprocessor (preferably one with 16 or more ADC inputs) and some "custom software" (which should not be too terribly difficult to get written.) Either that or 16 (LED is more likely than LCD, but you might get lucky) voltmeter circuits in parallel and stacked side by side (ie, 16 displays side-by-side, not one display with 16 sections.)

One old-fuddy-duddy solution would be the old (still in production, I think?) LM3914 or 3915 (linear or log) from National Semiconductor, wired into LED bars to make your display (you'd need 16, or 32 if you wanted a lot of detail (more than 10 segments) to your bars - one reason this sort of thing has mostly passed over to writing some code on a microprocessor rather than buying chips that don't need code.) BUt that assumes someone who can wire it up or design a PCB (which can be cost effective even for 12 units - but may not be as cheap as you'd like to go.)

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So far, seems do-able.

Deftly, he obliterates the easy path...

OK, what you want is an array of d'Arsonval mirror galvanometers and a light source/lens/screen suitable to make the dancing bars. Resistors set the scales.

An array of liquid-in-glass thermometers with power resistors glued to the bulbs might be a tad cheaper (includes the liquid, and the crystal, in the display...)

A 4" LCD is really small for 16 channels.

If there is nothing else on the display, that would be 1/4" per column.

Unless your on top of it, it would be hard to see. ( unless the goal is to have a 16 channel display, just to say you have a 16 channel display)

Ebay has lots of LCD displays and I am sure you will find one.

As has been mention, do you expect this to be a fully functional 16 channel display or is this a DIY project ??

h

e

=A0 =A0 =A0 X

=A0 =A0X =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0X

=A0X =A0 =A0 =A0 =A0 =A0 =A0X =A0 =A0 X

=A0 =A0 =A0 =A0 =A0 =A0X =A0 =A0 X =A0 =A0 X

X =A0 =A0 X =A0 =A0 X =A0 =A0 X =A0 =A0 X

obvious

t y -

Even more crude for an indicator - use one light bulb per channel. Incadescent bulbs have a decent dynamic range from about half rated voltage to full rated voltage.

LM3914's and ten-dot LED bars are still made, too.

I'm guessing you're too young to have seen these in use in actual commercial products... but they were!

Tim.

So, you basically want an 8-band graphic equalizer display ?

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Kind regards,
Gerard Bok

This is what I did with a large lcd display.

Display area is 8.5" x 2.9".

h

Isn't there a "thermometer-display" chip from National? ...Jim Thompson

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On a sunny day (Fri, 19 Nov 2010 18:24:27 +0000) it happened David Chapman wrote in :

There are LED bar driver chips, and little 10 LED or so display strips. Put 16 next to each other, and use 16 of those driver chips (come in log and lin IIRC). Of course I would use a 128x64 LCD graphics display myself. That would require some programming, but I have made some graphics PIC code available as open source:

it can even grab a screensot from the PC . With a big enough PIC that has 16 analog input channels it would be very few parts per unit. What is your budget?

lin IIRC).

I thought of that, but 128 wide /16 channels = 8 pixels per channnel.

With one pixel space between columns, thats 7 pixels wide.

Thats really small and up close.

h

parts per unit.

On a sunny day (Fri, 19 Nov 2010 15:34:27 -0700) it happened hamilton wrote in :

lin IIRC).

I count 21 characters nicely spaced apart on this LCD.

scroll to the bottom, teh image of the youtube video. You can even number the channels under the vertical bars 0-9 - A-F that way.

parts per unit.

I like the video from

Using graphic chars on a 20x4 charactor LCD.

A 16x4 LCD would fit the OPs requirements as well.

Now if the OP is a programmer, this would be an easy project.

h

On a sunny day (Fri, 19 Nov 2010 17:06:07 -0700) it happened hamilton wrote in :

Very nicely done! I dunno how much resolution the OP wants, this would only give 25%. And no space for numbering.

If he only wants to know the biggest then he only needs a 2 digit display from 0-15 :-)

Yes, the OP did state that he wanted a display of just the relative values.

I hope the OP is still around. :-\

h

.

Yes I am, and I'm most appreciative of the various suggestions that have already been made.

I certainly did consider the 3904 + 8-LED bar x 16 approach, but rejected it since it would be a LOT 'thirstier' and physically much larger than any LCD solution.

After reading all of the responses to my posting, I'm sure that an LCD design is the way forward so I'll now start looking for a friendly 'PIC expert' to write me a suitable bit of code ;-).

My thanks to all the contributors. I'm most grateful.

ATB - Dave

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David C.Chapman - (dcchapman@minda.co.uk)
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By LCD do you mean 16x2, 16x4 or 128x64 ?? ( charactor or graphic ?? )

A 16 char LCD is about 2" wide, your original request was for a 4" wide display.

In your original request was for a few units, how many is a few ?

Are you looking at doing any of your own assembly or for a completed unit ?

thanks

hamilton

Here are some graphic display sizes:

hamilton