Graphics LCD Driving using 16F877

[bluex_scf]

Hi everybody
I have an LCD screen with HD66205 and HD66205 modules but no graphics driver. So i have tried to drive the lcd panel directely by a Pic16F877 by generating the Frame signal, M signal, Data signals and so on.
No, i can successfylly write (and draw) on the screen. But the problem is that all the screen flicker and i have not found any information on the web on how to reduce flickering ... i do not know witch signal frequency to adjust (the M one or the Frame signal .) ???,
please help !
:?

 

[StupidDum]

I dont know how a graphical lcd works
if the lcd flickers, that seems like it is keep refreshing the entire screen
do u keep sending data? or send once, and just wait

 

[bluex_scf]

no, i have to refresh the screen continually, like as a crt screen !

 

[bluex_scf]

no, i have to refresh the screen continually, like as a crt screen !

 

[Nigel Goodwin]

no, i have to refresh the screen continually, like as a crt screen !

Are you sure about that?. The graphic LCD's I've seen (but never actually used) don't require refreshing, they work just like a text LCD - except more complicated :lol:

If the Hitachi ones are like that, I would upgrade to something better.

 

[StupidDum]

Are you sure about that?. The graphic LCD's I've seen (but never actually used) don't require refreshing, they work just like a text LCD - except more complicated :lol:

yea.. i have same opinion as well. LCD shouldnt function in that way.

 

[bluex_scf]

Yes ... LCD screens does not need refresh if they have a controller (like as Hitachi 1440 for text ones, ... and Seiko SD1350 for graphics ones ...
it's these controllers that does refresh for you ... so you have only to send data for them (commands or data) and they do the job.
THE PROBLEM :evil: I have a graphics LCD that DOES NOT have a controller, so i have to controll it myself using à Pic16F877 (i have to do all the job of a controller chip). I succeeded in doing all that and i can draw what even i woul like on the screen, but the problem is that i have an enoying flekering

 

[pike]

My lcd use to flicker when i left the bypass capacitors out. If your running your LCD off a battery, then you got me stumped