Friday, 12 August 2011

Arbitrary Doodle page




(It's what it says it is.)

Sunday, 7 August 2011

GLCD identification follow-up

I'm posting bigger pictures of the units along with the process of how I identified them. Part of this journey is my impatience*, and part of it is me just being dumb**, if you can own up to either of these cases, please read on; else go blame it on a Muslim.

1st unit I got as a gift, it's green, and has probably not blown up.
http://www.flickr.com/photos/40917542@N03/6018460771/sizes/l/in/photostream/ No datasheet, but identifies in my mind as something with Toshiba shipset, on account most chips bear the Toshiba name eatched or printed on them, and a clue in the silkscreen http://www.flickr.com/photos/40917542@N03/6018463107/sizes/l/in/photostream/ (top right) T12864 or 12864T. The next give-away is in the sticker in middle foreground of the picture, it says MGLS12864T. The way it's written on the chip 3 times over told me it must be identifying the chipset, and not the Toshiba-ness, so that warmed it up for me, I was initially lost on the pinout, hence it may have been damaged in my impatience already.

1 = Ground
2 = Ground
3 = +5V
4 = contrast (wiper of a 10kohm preset connected between Ground and +5V)
5 = negative acting (negative logic) WRITE
6 = READ (you can wire the /WR and /RD up using an inverting gate I expect)
7 = Enable - still not sure, but this appears to be the clock?
8 = Command /Data mode
9 = Reset pin, you might tie this to pin1 on your CPU, bit I prefer a R/C network
10 ... 17 = data0..7
18= font size, I tied this line to logic 1

The chipset is called 6963 which will net you the datasheet

2nd unit I bought, is blue but did not pay attention to the link to a datasheet. 
When I forgot** where I got the unit from I was in trouble. And even if I did I would not have worked it out anyway, so here is some help. The unit looks like this closer up from behind
http://www.flickr.com/photos/40917542@N03/6018466545/sizes/l/in/photostream/ , and front
http://www.flickr.com/photos/40917542@N03/6019017106/sizes/l/in/photostream/
Model is a 12864BG ,at this point it becomes clear that 12864 stands for 128x64 pixels, using a GB suffix in a google finds you a datasheet, this baby has 20 pins.
It's an LED backlit unit, the backlight wants between 3 and around 4V, I use a 100Ohm to the +5V rail, you can probably use less. Unfortunately I have blown up the LCD drive on this unit, which is the SMT chip on the top-left.
Pinout for GLCD

1= Ground
2= +5V
3= Contrast - wiper of 10Kohm trimmer, but this time connect the one end to VO (pin 18), other end must connect to ground I suspect
4= RS ?
5= READ / WRITE (write is negative acting)
6= Enable or clock the command into LCD
7..14 = data 0..7
15 = Chipsel1 (1st half screen)
16 = Chipsel2 (second half screen)
17 = Reset pin
18 = This is an output, connect to one end of the10K trimmer
19 = Led + (100ohm 3watt resistor to the 5v line)
20 = Led ground

The only thing left is to upload the datasheets, but they are copyright I suspect, hold that thought, maybe some fresh links.

Legend :
** = I am dumb
* = I'm impatient