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 Post subject: S1D13700 not working
PostPosted: Mon Nov 02, 2009 19:40 
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Joined: Sat Oct 31, 2009 2:03
Posts: 3
I have a United Radient Technology UMSH-7567 320x240 LCD with an Epson S1D13700 controller. I have wired it up according to this table http://imgur.com/tHhmF. I'm not able to get the LCD to display anything. I have tried in both 6800 and 8080 modes. The timing appears to be correct when I use an oscilloscope to look at the data lines.

I was wondering if it might be a contrast problem? The documentation mentions nothing about changing the contrast, but looking at other LCD's, the VEE always seems to be used for contrast. My documentation says to not connect VEE. If it is not contrast, then I am out of ideas.

Any tips for how to get the S1D13700 working?


-Rick


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PostPosted: Sat Nov 07, 2009 23:02 
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Joined: Sun May 05, 2002 22:05
Posts: 2063
Location: Lappeenranta, Finland
Are there any trimmer potentiometers on the display PCB? If there is then I guess the display probably has built in DC/DC converter for generating the VEE voltage so no external connection should be necessary. But still the contrast voltage usually needs to be adjusted to the correct level using the potentiometer.

If you are able to post a picture of the back side of the display then it might also allow giving some more suggestions about this.

If you measure the voltage at the VEE pin what do you see?


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 Post subject:
PostPosted: Mon Nov 09, 2009 23:24 
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Joined: Sat Oct 31, 2009 2:03
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I do not see any trimmer potentiometers on the display PCB. http://imgur.com/M579i.jpg

The voltage on the VEE pin is around 34mV.

VEE is connected to U7, a quad ground sensing operational amplifier, at pin 4, which appears to be Vcc of U7. It is also connected to R7, C10, C11, and several of the components that are not stuffed.

Let me know if you want me to probe anything else.


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PostPosted: Tue Dec 01, 2009 19:42 
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Joined: Sat Oct 31, 2009 2:03
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I have made some progress. It was the LCD that was the issue. I ordered a batch of the same LCDs from a different supplier which contained all of the components that were missing from my first LCD.

When I plug in the LCD, I now see random pixels light up. I am also able to turn on and off the LCD using the Display ON/OFF command, but nothing else seems to be working.

When I issue the Display Off command, the display goes mostly off.. it shows three lines across the LCD. http://imgur.com/0fSrc.jpg
When I issue the Display ON command, all of the pixels on the display light up.http://imgur.com/SIt6A.jpg

I am following the initialization example in the S1D13700 datasheet, and I see no mention of timing between commands. What sort of timing delay do I need between sending a command and sending a parameter? Also, there is a part in the initialization example that mentions clearing the first and second layers of data display, is this automatic, or do I need to issue a command?


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