Reverse engineer an LCD display - The first patterns and how it works (finally) [PART 2 of 3]

[ixamraxi]

Very cool, thanks for the useful information =)

[herctrap]

nai alla stin kafeteria dn tha exeis kati animated alla 10 eikones

opote dn tha fente to flicker

tha stelneis tin eikona kai telos

meta apo merika sec i epomeni eikona

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apo oti katalava dn mporeis na prostheseis kati stin eikona pou idi exeis steilei

prepei na tin steileis pali apo tin arxi me ta nea dedwmena

e?

[pcbheaven]

@herctrap (english for this is interesting for all). The problem is that each horizontal scan line, is enabled ONLY once per refresh. There are 240 scan lines. The process to show an image is the following:

1. Send all 320 bits (in packets of 4) for one scan line

2. show this scan line

3. send data for next scan line

4. show next scan line

n... do this for all 240 scan lines and restart

That is why there is flickering. Note that this LCD has no controller. I make the controller myself.

[herctrap]

@pcbheaven

i am not sure

but is this right

rise the scan line clock

set the row pin HIGH or LOW

rise the "row"clock

and you are repeat the above two lines for 320 times per scan line

so we you are saing in packets of 4

whats the diference?

[pcbheaven]

@herctrap packets of 4 means that for 320 bits, you need to send (320/4) 80 pulses, and in each one 4 bits are sent. The rest process you got it correct. In a few hours, i will upload the last (third) video in which i demonstrate a proper screen and how exactly it works.