Try connecting pin 18 to pin 3 , that will give you max contrast ,but you would be better with a 10kpot in there , you have no contrast the way you have it wired
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| Help with wiring Samsung KS0107/0108 to parallel port http://forum.lcdinfo.com/viewtopic.php?f=6&t=1189 |
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| Author: | thilan29 [ Fri May 06, 2005 16:50 ] |
| Post subject: | Help with wiring Samsung KS0107/0108 to parallel port |
Okay I have a 128x64 LCD made by TinSharp and here are the specs: Driver/Controller IC: Samsung KS0107 / KS0108 (COB) or equivalent PINNING: 1. GDN 2. VDD 3. V0 4. RS 5. RW 6. E 7-14. DB0-DB7 15. CSA 16. CSB 17. RST 18. VEE 19. BLA 20. BLK Here is the PDF for the unit http://www.tinsharp.com/product/MANNUL/TG12864B.pdf I wired it according to http://www.skippari.net/lcd/ks0108.html except that I grounded LCD pin 3 (to give full contrast) and left LCD pin 18 without anything. When I do wire it, do I HAVE to ground ECP port pins 18-25 or can I just leave them be? As it is now, the backlight turns on and that's it. I tried running LCDInfo 0.3.2 on a Win2K machine. The driver is set to KS0108 in LCDInfo and the program starts but shows nothing on the LCD screen and doesn't show "goodbye" when I exit. I believe the port is set to ECP as LPT1. Please help. I'd really like to get this working. THank you. [/url] |
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| Author: | thilan29 [ Sun May 08, 2005 5:52 ] |
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Anyone? |
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| Author: | mingingbollock [ Mon May 09, 2005 14:50 ] |
| Post subject: | |
Try connecting pin 18 to pin 3 , that will give you max contrast ,but you would be better with a 10kpot in there , you have no contrast the way you have it wired
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| Author: | Cossie [ Tue May 10, 2005 0:28 ] |
| Post subject: | |
I had the same problem with a KS0108 LCD and it turns out that it wanted negative power to fire up the display so you could try supply it with -5 v at pin 3. Note. Some of the IC's got warm when i supplyed it with plain GND therefor i tried with -5 v. Regards Michael. |
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| Author: | thilan29 [ Tue May 10, 2005 6:36 ] |
| Post subject: | |
Other than the contrast, is there any other problem you see with the wiring? And Cossie, did your display work fine with the -5v?? And to be sure, I should supply the -5v to pin 3 and leave pin 18 alone or connect pin 18 to pin 3 also? THanks for your help. |
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| Author: | Henri [ Tue May 10, 2005 18:21 ] |
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Just connect the contrast like in the schematic you linked to in your first post. Pin 18 is negative voltage output, about -5V I guess. Then you need the potentiometer to adjust the contrast or then try several different resistor values to figure out a good combination to have a suitable voltage divider. The voltage needed in pin 3 for normal contrast could be something like -2 to -3V. Connecting it the GND doesn't give any contrast and full -5v should give full contrast meaning you don't see anything than fully white screen again. So you need pretty close to correct bias voltage to see something. |
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