LCD Help Please

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Michael 19 years ago

Hi,

I've picked up a sonar fish finder which features a square lcd screen which is about 9cm2 big. As I've got an interest in these type if things, I've taken it apart (as you do :-) ) and have been looking closely at the lcd screen/output side of things.

The screen works with a depth digital readout at the top. Then has small fish shapes in a grid across the middle and bottom. When a fish is detected, the fish furthest on the right is lit and then moves to the left as more are picked up. The right line of fish therefore contains an up to date picture as it were. Having taken the thing apart, I've noticed there are about 30 contacts - tiny pads, to which a pink/black sandwich strip is applied with the lcd screen stuck on the top of that.

My question is, if I were to identify which pads controlled the right column of fish, could I then amplify the signal and connect them to a microprocessor/computer etc.?

Cheers,

Michael

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Eeyore 19 years ago

Conceivably but it would be one heck of a job !

Graham

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Michael 19 years ago

"Eeyore" wrote in message news: snipped-for-privacy@REMOVETHIS.hotmail.com...

lol well, see how it goes...

Is it likely that each pad is a fish as it were?

Do you know of a better method?

Thanks

Michael

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Chris 19 years ago

LCD displays are driven with AC (switched DC alternating + and -) applied at several KHz. You would have to decode the signals applied to the display before you would be able to use them. That's a *big* hassle to do -- I did it once for a simple 4 digit 7-segment LCD display because there was no other way, and would rather not do it again.

Each pad may be half or a third of a fish, depending on the setup. Theoretically, you could do it. But it would be much easier to find another way, as Graham suggested. First of all, try to get the manual for the fish finder and see what you have to work with. Many of them do have some kind of output, and that would be a start.

Either that, or you might want to google

"sonar fish finder +RS232"

for a selection of units that have a serial output. You can then read that into a PC or single board computer, and do what you want with the data.

Cheers Chris

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Peter Bennett 19 years ago

On the sounders I've used the screen is made up of square "pixels", and a single fish symbol will cover several pixels - if you look closely at an active display (if you haven't broken it :-) ), you should see the individual pixels.

Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca

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Homer J Simpson 19 years ago

"Michael" wrote in message news:DJnKg.198512$ snipped-for-privacy@fe2.news.blueyonder.co.uk...

Depends on your skill level. It sounds like you should go further back in the circuit and pick up your output there. I assume this thing has a processor?

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Michael 19 years ago

Well here's some pictures of the pcb:

formatting link

The fish finder doesn't have any other form of output just the lcd. It looks like the fish are single shapes/pixels. There is space between them when they're all lit up.

So is my lcd hack the only option?

Cheers,

Michael

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Homer J Simpson 19 years ago

"Michael" wrote in message news:bqFKg.200426$ snipped-for-privacy@fe2.news.blueyonder.co.uk...

The modern way: don't build it FROM components, it IS a component - all of it.

Yes, but a horrendous one to apply IMO. You'd almost be better off to 'read' the screen with phototransistors!

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