Powertip PG12864 and Mega 2560

I use u8glib library, because it seems best... I have predefined constructor for u8glib and i connected display to match this settings..

I have simple potentiometer between +5V and GND to control contrast. I saw something about negative voltage but in datasheet which i found is nothing about it... And some websites have schematic with simple potentiometer... I can see information that black horizontal line doesn't mean constrast voltage is Ok... Do you have some tested schematic for this converter? I will try it on the weekend.

Thank you for your help Jan

Hi

This is what i have seen on http://www.powertip.com.tw: - Your display does not have the original T6963 chip but a (hopefully) compatible SAP1024B - There seems to be no negative power converter

For testing i suggest to use an external power source. Batteries could be fine also. I have used a power supply with variable voltage output for my display during testing phase:

On the picture the battery drives the backlight. The external power supply provides the negative voltage. The red and black "Clamping hooks" provide the -15V for the contrast of my display. Note, that the red (+15V) cable of the power supply is connected to GND of the display. The black clamp (white cable) is connected to the contrast input. The Arduino is powered by a laptop which runs on battery power. To avoid conflicts with your 220/110 AC powered devices, do use only one device powered from 220/110 AC.

Meanwhile i have replaced the power supply by a negative converting module (AM2D-0515DZ)

Please note that your display might require less then 15 volt.

Oliver

It is interesting, i found datasheet http://www.noodlehed.com/ebay/datasheets/pg12864f.pdf and there is T6963 chip in schematic and on powertip website is SAP1024B chip... But physicaly my LCD have Toshiba T6963C chip. It is some year old and i receive it as gift.

if i understood well, T6963C chip needs negative voltage supply...

The PG12864 is a module, it has several parts. The T6963 is just the controller and requires only +5V to work. But the negative voltage is required for the LCD component for the display module (and yes, i think it is passed through the T6963). Other components include segement driver and RAM. The negative voltage converter is optional and often not included.

A digramm for a module with NV can be seen here: http://www.lcd-module.de/eng/pdf/grafik/p128-7k.pdf

Oliver

My LCD is working!!! It needs voltage from -4,5 to -5,2 V to set contrast...

Thank you for help!

Jan

Thanks a lot for the feedback!

Oliver