LCD 12864 with GT2560

[rmrodrigues]

I need change anything related with the voltage? I thought that I only need change firmware. What I need change?

[rmrodrigues]

Hi,
I need to do any electronic modification? I thought that only it was necessary change firmware.
What I need change?
Thanks.

[Mark]

I mean the output of the PSU, is it 12V? and the board, does it have 5V too? And if the PSU output is too low, how about adjust the trimpot on the PSU, beside those terminal blocks?

[oklement]

Hello
I have the same problem. The voltage is correct 12,1V. System with LCD2004 works correctly display is OK. with the full graphic adapter the display is blinking. As I take out just the SD card cable, everything remains black without any blinking . With character display it is displaying so as well, Are any other solution available?
sincerelly
oklement

[Raisa]

Hello,
I got the very same problem of a blinking & buzzing LCD when I try to use the GT2560 with the LCD12864.
I have tried different vendors already (Geeetech, Reprap Discount and bigtree...), all have the same pinning for EXP1 & 2 and all react the same way.
I would assume, that not the compilation is the issue... the define was set for the LCD12864 and the one for the LCD2004 was commented out.

Maybe the pin mapping is incorrect, so I would ask kindly to release a firmware here for us, properly preset for the LCD12864 for both the I3 Pro B and the I3 Pro C.

This is DEFINITLY not a power issue, since both displays are powered using the 5V, so it is nonesense to assume that the power supply would be to weak

Please help us out here, Geeetech, as soon as possible...

[Mark]

have you guys used the correct firmware? I mean sometimes when you use the wrong firmware the LCD will beep all the time.

[Raisa]

Hello,
yes, I used the firmware from a post here directly from Geeetech for the I3 Pro B.
Then, the defines were modified accordingly and then goes the blink/beep issue...

[Mark]

wierd...if you use the correct firmware and select "full graphic smart controller" in the firmware, then it should be work. How about the LCD itself, is it have a short somewhere? a solder bridge on the mainboard or the LCD itself?

[Raisa]

Hello again,
Since I have tried all kinds of LCD12864 here, it could not be that all would have some defect.
I simply cannot understand the issue... I will go in depth with the LCD12864 pinning and wire them one by one using Dupont cables.
It must be something else... I will post my findings as sonn as I get any further with that issue here.

[Raisa]

Hello Mark,

got the Problem fixed...
All others, be careful with the LCD12864 from bigtree-tech.com !
This display has 180° rotated EXP1 & EXP2 connectors!
This way, the buzzer gets connected to VCC (5V) and this causes this result of blinking & beeping.

I solved this issue by cutting the index of the connector on the EXP1 & EXP2 connectors on the opposite site, so that the ribbon cable could be inserted.
Now it's fully working... Always use a multimeter to doublecheck manufacturer's pinning... the Display might look the same, but some vendors seem to mix up the pinning...

Thanks Mark for all your help!