Faint line across middle of display
Are using the S128240d-FC-BW-3, and despite all attempts to optimise is out, I have a faint horizontal line right across the display, bang in the middle. Dark content looks lighter, and light content looks darker. This is despite have actual content, or setting the whole display all on or all off.
Its a little hard to tell, but I believe the lines are COM0 and COM1
In desperation, i have taken the approach of tweaking pretty much every attibute, but have not been able to resolve this. Is it possible that such an effect can be caused by hardware? ie, from coupling issues or supply stability?
Setup :
Circuit design as per datasheet for 6x boost
3v3 supply
8 bit 8080 interface
144 duty, 1/12 bias
Com scan 0-79, 80-159
Normal display, 3b3p
Has anyone experiences this before, or have any ideas?
Cheers
Hi Brenhale,
As a quick test, try setting not only the pixels on the display area, but all those in the RAM (i.e. pixels 0..159 x 0..255) to 0x00.
Regards
Martin
I was already doing that for the 160 lines but i changed to all RAM (the extra columns 241-254) to be sure, but no change. Either all on or all off. Using the partial display command has no effect either.
Interestingly, i don't remember seeing this effect whilst using the external supply during earlier development.
The solution was to change the order of the COM scan such that it scanned across the physical display in order, rather than across the driver chip outputs in order. ie, changed COMSCN from '0' to '2', tweaked the addresses, and the problem magically disapperared :)
