CFAG12864B-WGH-V Question

[Scatman]

I've got a CFAG12864B-WGH-V and it is all wired up. I thought I had it wired up correctly but I guess I don't.

Everytime I try to update the display, the LCD would flash, but it wouldn't display any information.

My question is, do I have a wiring issue or a timing issue? Any idea what line might cause that error?

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[CF Tech]

What software?
What schematic?

 

[Scatman]

I'm using lcdinfo. I have also been pointed to a number of different test programs all of which produce the flashing.

Some of the lines from my parallel port to my lcd are slightly different length, so, I'm fixing that to see if it helps.

Otherwise I'm using this schematic.

I'm using a 20 ohm resistor for the backlight, not the 3.9 ohm one listed.

 

[CF Tech]

Line length within reason should not be critical.

You probably have a gross wiring error somewhere. You might try CFAH_WinTest to test the wiring (no, it will not init the display, but you can toggle each line in the software and use your ohmmeter to see if the correct line moves at the display).

Make sure that adjusting the pot sweeps pin 3 from +5v to -5v. Try about -3.5v for starters.

You have an EL display, so you will need an inverter to make the backlight go. The 20 ohm won't hurt, but also will not light up the backlight.