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The Master
- 16th June 2012, 13:29
Hi, I'm trying to control a WG12232A-TMI-NA LCD display. I've been reading the datasheet (http://www.rapidonline.com/pdf/57-2272.pdf) but I'm struggling to get it to do anything.

I found the datasheet (http://pdf1.alldatasheet.com/datasheet-pdf/view/234816/ETC2/SBN1661G_M18-D.html) for the SBN1661G_M18-D chips that are controlling it and it looks like there are more pins than what the complete module exposes. I assume that some of the pins are internally tied together but I can't see any information on that.

The main question at the moment is: What is "E"? It looks like some kind of clock input similar to the one used in SPI so it must be important but there's no sign of an "E" connection on the module.

Charlie
- 16th June 2012, 14:14
The data sheet is a bit confusing, and E has different meanings in different locations. If you mean the read / write configuration tables, most likely "E" is for write "Enable" . Low it enables writing to the display. (also called not RD, or RD with a line over it)
These displays are notoriously slow, which might be why you can't get it to do anything. Use long delays between everything you try to do.

The Master
- 16th June 2012, 14:29
Does "E" have the same meaning in Fig.24?

My PIC is bit-banging the data out with 200ms pauses. That should be more than slow enough (I hope).

Just to clarify, is the data clocked in using a signal from the PIC like in SPI or does it have to be synced with the module's internal clock?

Originally I thought that E and CS were the same thing or at least tied together but looking at Fig.24 it looks like they must be separate. If I understand right then I have R/(not)W on pin 9, (not)C/D on pin 4 (A0) and (not)CS on pins 5 and 6 (CE1 and CE2)

The Master
- 16th June 2012, 19:29
Well, it looks like it's working fine now. I had quite a few problems that wern't helping like accidentally mapping the command/data line to the wrong pin on the PIC and timing things completely wrong.

The chip enable pins (CE1 and CE2) appear to be the "E" pins of the 2 chips in the module. I think that the CS pins are held low so both chips are permenantly selected but data can still be clocked into each chip individually.

My working timings don't seem to match up with the datasheet so I think they are still not quite right and I'm still misunderstanding something but it is working so the next thing I'll do is adjust the timings and speed everything up until it's working as fast as possible.