LCDInfo.com

Hi everybody!
I am experiencing a strange problem with the clone of Nokia 6100 color LCD:
I have studied the dedicated topic, and my display is working, BUT... only some times!
I have my custom pcb, 3.3V powered with a step-up from the 2.4V of 2 AA batteries, this circuit works good (I checked the presence of the 3.3V at the lcd and everywhere in my board), and these 3.3V are taken to 7 V with another stepup.
This circuit works good too, the lcd powers up, but the problem is that sometimes it works (display characters, graphics) and sometimes not (remains blue).The rest of the circuit is working all the times correctly.
The LCD is located in a board different from the main one, connected by wires. I checked with the tester the connections and they're ok, too.

Do anybody have a tip about where the problem could be?

all the best, thanks since now,

Cirutech

What type of processor are you using ?

how long are the wires to from the CPU to the LCD ?

some things I would check...

noise on power supply & data lines.
temporarily slow down the communication to the LCD, to see if that helps.

Hi,
I am using a PIC18 processor (18LF4520) and the wires from the mainboard to the lcd are about 5cm long, plus another 3cm of tracks on the pcb.
I tried to slow down the communication speed, but the behaviour of the lcd is still the same: sometimes works, sometimes (more often) not.

I think that maybe the problems could be in the settings stored in the internal eprom of the lcd controller, but I have no way to check this!

I know that my problem is quite strange, but I have no idea on what to work on... if the lcd was not working at all, I could think of an HW problem, but in this way I don't have any idea on where the problem could be...

Any help is greatly appreciated, all the best,

Cirutech

Have you tried using a different power source, maybe an a/c to d/c converter (like the ones you plug into the wall). You're problem may be power related....just a suggestion. Seems like an aweful lot for 2 AA batteries to run.

Hi again everybody!
My lcd keeps driving me crazy! I tried to fix my code, and everything seemed to work well, I've also implemented characters and the LCD works fine, but... but now seems dead,again. The screen is full blue and now, after 2 days of full and normal working, with the SAME code, nothing to do.

to all you that have a full working lcd: can you briefly describe your HW setup and your initialization routine of the lcd controller?

any help will be greatly appreciated, all the best,

cirutech

How's you reset hooked? If the reset signal isn't kept steady it can cause such behaviour.

Hi,
my reset is low at startup of the com between PIC and LCD, I pull high, start the COM and I keep it high all the time. never low again

thanks,

cirutech