ks0108b/ks0107 controller combo

[mister_e]

**broken link removed**

http://www.kpsec.freeuk.com/components/vres.htm

Vo is pin 3 on the GLCD schematic
**broken link removed**

 

[desaila]

Ah, I knew what it meant.. just never called it a wiper before, aha. But why does VO need a pot for this type of glcd?

 

[mister_e]

Kind of universal 'view angle adjustment'.

 

[desaila]

alright, i hope you can pardon the fact that i'm sort of new to this, but what do you mean by "view angle adjustment" ?

the data sheet I have for the lcd I have doesn't really specify that much outside of timing diagrams and pinouts.

 

[mister_e]

No problem, here's some short and generic explanations.
**broken link removed**

Some will also call it contrast adjustment... which is probably the right term

 

[desaila]

Ah, the lcd i'm using has VEE as the contrast adjustment. Or wait... does it need VO and VEE tied to the same pot to adjust the contrast?

**broken link removed** <-- what i'm using.

 

[mister_e]

Refer to the schematic previously suggested.

 

[desaila]

Refer to the schematic previously suggested.

I see what's happening, I just don't understand why. Like I understand the connections in the circuit schematic, but I don't understand the reason why it's wired the way it is. I read that thing about the view angle as well, and it only says "do it this way," rather than "this is why it's done this way."

 

[futz]

I see what's happening, I just don't understand why. Like I understand the connections in the circuit schematic, but I don't understand the reason why it's wired the way it is. I read that thing about the view angle as well, and it only says "do it this way," rather than "this is why it's done this way."

I didn't totally understand why he did that either, so I just copied him.

 

[desaila]

I didn't totally understand why he did that either, so I just copied him.

aha, alright. I have a contact at the company that I've been dealing with on a regular basis, I'll forward him the schematic and ask him what he thinks of it, and if he gives a better answer I'll post it here for the sake of knowledge

 

[blueroomelectronics]

VEE is a negative voltage generator built into some GLCDs.

 

[desaila]

Alright, I have the new lcd all wired up, and it's functioning just fine. To try and verify it was working I tried running the hacked up version of futz's code I had, with the LAT's in place, and other initializations, and I'm still not getting _anything_ to display.

I realized why I fried teh last one, and that is because I was forcing a positive voltage/current into Vee, and since the guy from blue room electronics pointed out that it's a negative voltage generator, I can see this being a problem--or an escape for the special smoke.

Anyway, like I said in a previous post our group has everything else done for this circuit and programmed a simpler lcd in case we can't get this going. Thanks for the help!

 

[desaila]

Hey, I finally got the LCD working. I worked with Pommie's code because it was displaying something static. I initially had the lcd wired to PORTA, and I think that might have been part of the problem. Furthermore, I copied the PORTD initializing info off the data sheet, inserting assembling to clear PORTD/LATD. So, all the PORTD pins are assigned to the control pins, and the data is tied to PORTB.

Honestly, I'm not sure why it's working now. Part of me thinks that I wasn't initializing PORTA correctly, and that due to the simplicity of PORTD and it's lack of difficult initialization.

Thanks for all the help and holding my hand along the way.