Assistance with displaytech 32128 LCD please?

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Folks,

I'm trying to use a displaytech 32128 LCD display (http://www.rswww.com part number 627-1668) which as far as I can see from the minimalist data sheet on the same page consists of some bendy stuff, some LCD stuff, and an ST7565V controller chip http://www.sitronix.com.tw/sitro...

I haven't purchased it yet, but it's looking good... if I can work out how on earth to connect the blasted thing.

I'm sure all the info is in those two data sheets, but I haven't got my head around it yet. As far as I can tell...

- the Vdd positive supply should be 3.0v
- the Vout supply should be 6.9v
- I need to provide decoupling caps on V1-V5
- I can't use the voltage multiplier circuit *unless* I can get away with the doubler, Vdd = 3.3v, and Vout = 6.6v, supplying necessary caps
- I will need to set all sorts of stuff in the internal registers to control the voltage.

Aaaaagh! Anyone got any experience of this chip?

Thanks,

Neil

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I had a look at those datasheets too, and I accompany you with the "Aaaaagh".

It will be tough to sort out all the commands. I looked around a bit more, but no better data found. Sometimes I wonder what monkey was asked to write the datasheet.

Nard

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tessa and Tina, You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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Damn, I saw an answer to my post, leapt for it, and discovered it's as bad as I thought it was... but thanks anyway for confirming my original opinion.

Problem is, I think, that the original data sheet fails to make any correlation between the various voltages available at the interface, and the spec in the sheet. Also, they've chosen different names from the chip supplier, too :roll:

I'm going to work on the assumption that 1u and 100n caps all round are probably a good start as it's a small display... as far as I can tell from the seventeenth reading, I *may* be able to set the voltage as a quadrupler (it goes negative, it seems!) and use the internal 'volume control' to set the limit for V5 - start in the middle, see how it goes. I think that should set the contrast, if I understand it correctly.

Actually driving data to the display is a piece of cake, it seems, once you've worked out which of the parameters are actually required to make it light up.

I sense some dark boxes approaching...

Neil

(and after I've done this, I want to do the same for the rather delicious (and unfortunately discontinued) Pictiva 256*64*16 grey, which has even less helpful data... you'd think they didn't actually want anyone to use the damn things...)

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OK, next time I'll warn you on forehand via PM ;)

The good things:
1. pixel-location and internal bitmap are 1:1 correlated
2. at least it HAS a voltage-multiplier .... many others don't
3. it has two nice interfaces: parallel: with readback-mode, but takes many pins, I2C: nice on pin-use, presumably no read-back (which sucks for graphics)
4. it's really low-cost :)

Nard

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tessa and Tina, You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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(4) yerrsssss... problem is, some jester reviewed the car for which I developed my ECU reader widget, and listed the widget as a must-have accessory. A couple of weeks after I'd decided not to continue with it, as the cost was getting exorbitant :roll:

Now, of course, I have a dozen requests and more in the pipeline.

Although this is completely different from the display I was using - an eighth the price, for one thing, it orders its display in a similar manner so I can transfer everything except the lcd_init and lcd_write routines. Pins aren't a problem, I only use four for serial comms.

Also, the previous version tended to be fairly closely tied in with the motherboard; with an 18-pin pin connector soldered both sides :shock: it's a bit tricky to replace. This should be easier to change.

Neil

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The Pictiva display I've got (96x36x1, Galaxy white, I have a thread on it) was not too difficult to bring to life. Osram has an application note for these series of displays with a C example on how to initialise the registers (suggested values are in the display type specific datasheet). You can download a datasheet for the SDS0323 from datasheetarchive.org. The 4 bit SDS1323? is the almost the same.

I also have bought one of the last 128x48x1 Lime Green Pictiva displays Farnell has in stock 8) I just have this 'fetish' for displays :oops: :)

So sad they stop making them :cry: :cry: :cry:

I'll now study the Displaytech datasheets ;)

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What I've understood so far:

The controller chip has a step up convertor based on switched capacitor voltage doublers. Depending on the ratio you need to connect capacitors in special ways. This is shown on page 32/39/40.

The Displaytech d/s talks about 6.9V, so I guess you need to triple the 3V to 9V, and set the, what Sitronix calls a 'volume' setting :?, to 6.9V by setting it to internal resistors mode and set the 'volume' register to the proper value. This alfa value can be calculated by the equations on page 33.

I think is the most difficult part, the rest of the command seem pretty straight forward.

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The display I have in mind is the RS part number 654-2033 - it uses the STV8105.

I've attached a zip file with my proposed connections; zipped because it's 3000 wide. Comments would be appreciated - just the LCD connection; all the rest is known to work.

Neil

Edit: Jayjay, I think we're looking the same way. I figured multiply by four and work from there, though.

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Oh... I have no experience with the STV8105 :)

ZIP won't open, gives 'corrupt' error (I use XPs compressed folders).

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The famous error at the tail of the zip-file ... like a dragon. And a zombie: it comes back from time to time. It is not an XPissue. The file IS damaged ...

Neil, if you use 7z as zipper, it will survive the freaks-site-software-check.

Nard

http://www.7-zip.org/

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tessa and Tina, You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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Hmmm... curious. It's compressed with Linux 'zip 32128.zip 32128.png'; the zipped version decodes ok (with 'ark') from my local copy, but not from the downloaded version, either directly or saved. Investigation reveals that the downloaded version is 200 bytes shorter than the one I sent :?

Is this something that Freaks does to the file I've failed to notice before?

Aye well, I've attached a slightly smaller crop of the drawing uncompressed. Apologies to the IE users, who will now suffer wide pages as it appears to be unable properly to scale drawings.

Neil

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Quote:
Is this something that Freaks does to the file I've failed to notice before?
Freaks server indeed. Error resurfaced. 7z is great. Not sure if there is a Linux-version.

A GIF is worth a thousend words   They are called Rosa, Sylvia, Tessa and Tina, You can find them https://www.linuxmint.com/

Dragon broken ? http://aplomb.nl/TechStuff/Dragon/Dragon.html for how-to-fix tips

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