Display problem - Lag-fade in menu pages and -SOLVED

[denis]

Hi all,

I'm here with my last problem and I'm sure this will the last one if I can solve. I reprogrammed atmega and finished the box and pre-artwork of it. The problem was exist before programming but it was better to show it to you.

Finaly I took a cam from my borther inorder to capture the last problem with my megadrum since I tought it will be more clear to show it in a small movie other then trying to describe it by words.

Anyway there is a problem with display. It's something like a lag or fade. When I hit a pad vu meter does not react fast and shodows of previous hits keep on display. During menu pages lag-fade between changes are more clear. When I jump to next page in menu shadow of the previous page fades out with fade in of new page and It makes really hard to make settings.

Movie is about 44mb-1min and it's not so clear but I think exactly shows the problem.
http://rapidshare.com/files/112808958/MVI_0677.AVI.html

I have tried a different lcd display and it's same. Also both Lcd's are working perfect on other megadrum unit. What part can be the source of the problem, do you have any idea?

here are some some pictures of my new megadrum kit. It's not finished yet sbut wanted to share some early pictures of it with you.


Any help is welcome and thanks.

[dmitri]

I looked at the video. Very strange behaviour. Even though it is recorded out of focus, the lag appears to be effecting the LCD on per pixel basis. There is no way MegaDrum itself can do it itself. What are the voltages on pins 1, 2 and 3 of the LCD?

P.S. Very optimistic looking drum kit:)

[denis]

I'm not able to measure voltages at home. I'm just a starter at electronics and doesn't have a multimeter. are there any possible peice to replace that can be responsible for this behaviour or I should visit someone to get the voltage values at pins?

[dmitri]

To be honest I'm struggling to come up with any idea why it could be happening. The lag effect appears to be of physical nature - individual pixel's liquid crystals are slow to react to electrical potential changes. I can only suspect that voltages on the pins 1, 2 and 3 are out of allowed ranges. Are you sure pins 2 and 3 are properly wired?

[denis]

I'm sure that lcd is ok and working poerfect with other megadrum. Tomorrow I'll ask to a local electronic shop for the measurement.
Is that pins are enough or do you need any other measurement?

Btw I really love my kit ehehe and I owe it to your design. It encouraged me to start this new project.

[dmitri]

All other pins are data pins. It is obvious data are received by the LCD correctly since when the info on the screen is static it is displayed correctly. So it is not need to measure signals on other pins.
Did you use Synthex's PCB?

[denis]

yes it's synthex's kit with pullup resistor modification.

[Synthex]

Very strange problem !
Are you sure there is no short-circuit on the PCB (LCD connector) ?

Your drum have a very nice look !!

[denis]

Thanks about the comment about the kit but wait till it end=)

I2m sure the connector is ok. Tried it with and other connector also which is working ok with other unit.

[elrules]

Are you running some kinda Windows Vista on megadrum? I'm sure that must be the problem...