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Posted: Wed Jun 19, 2002 8:07 am
by Dexter
i have the first original GLK12232-25, not -SM or -WBL, and i was wondering if there is anything special i have to do to set it up to use I2C mode. I am trying to interface the LCD with a PIC16F876. I see for -SM there are a couple steps you must take to activate I2C mode, but no such mention in the other manual / datasheet.

and by any chance, would someone know if i need pullup resistors on the SDA and SCL pins?

thanks!

Posted: Wed Jun 19, 2002 8:34 am
by Pheonix

Posted: Wed Jun 19, 2002 9:13 am
by Dexter
On 2002-06-19 08:34, Pheonix wrote:
Check this: http://www.matrixorbital.com/manuals/gl ... /index.htm
I don't have the -SM. The back of my LCD looks very different from the image in that manual. I looked through both the -SM and the -WBL (replacement for regular GLK12232-25) and neither are really helping me, unless I am totally missing something in these manuals (probably :sad: )

Posted: Wed Jun 19, 2002 9:22 am
by Pheonix
/me shouts Heeeeeeeeeeeeeeeeeeeeeenrrrrry

Posted: Wed Jun 19, 2002 10:56 am
by Henry
HEHEHEHE.. I'm here, I'm here..

Dexter, the GLK12232-25 and GLK12232-25-WBL are almost the same thing... (the -WBL has hardware scrolling). As for the pull up resistors, the display does not have pull up resistors on the display or have spots on the board for them. I would add 2.7K resistors onto the master (or in the cable it self)..

To talk to the LCD is not much different then over RS232...

Here is more info from the manual (it's not in the graphic ones yet, sorry)

The idea of ACK is to indicate when the data has been received correctly. ACK does not indicate data incorrectly received. ACK simply fails to indicate when data is correctly received. Clearly, this is of limited usefulness and even less so with Matrix Orbital modules. Matrix orbital modules are not capable of failing to acknowledge an incorrectly received byte in response to that bytes transition. They are only capable of failing to acknowledge the bytes following the byte, which was not received. To fully understand the reasons for this one needs to understand something about how a Matrix Orbital module processes data. Basically the reason why a Matrix Orbital module might fail to receive a byte correctly is that it was unable to process the byte previous before the failed byte was transmitted. Because the module cannot possibly know that it would be unable to store the byte before the next byte was received it cannot know to not ACK. The reason for this situation in deference to situations you might be familiar with (i.e. memory chips, etc

Posted: Wed Jun 19, 2002 11:18 am
by Dexter
mmmmm info....thanks henry. thanks alot!
important stuff there, with all that 7 / 8 bit stuff.
so the module is ready to go to use I2C, just start sending data to it and it will know? no jumpering / cutting connections?

Posted: Wed Jun 19, 2002 11:22 am
by Henry
yup...

Posted: Wed Jun 19, 2002 1:04 pm
by Dexter
On 2002-06-19 11:22, Henry wrote:
yup...
sweetness. thanks again, im gonna make a feeble atttempt at getting I2C up and running later when i get home.

Posted: Wed Jun 19, 2002 1:31 pm
by Henry
Good Luck...

Posted: Wed Jun 19, 2002 6:38 pm
by CriticalPoint
Wrong button


<font size=-1>[ This Message was edited by: CriticalPoint on 2002-06-19 18:39 ]</font>

Posted: Mon Jun 24, 2002 4:31 am
by Dexter
Henry,
I tried getting this going and I am having MAJOR problems. After doing extensive testing, I am thinking the LCD is at fault. I will email you with more detail.

Posted: Mon Jun 24, 2002 5:23 am
by Henry
OK.. got the e-mail... I will post some of the stuff here for others to read.

Posted: Mon Jun 24, 2002 8:13 am
by Dexter
On 2002-06-24 05:23, Henry wrote:
OK.. got the e-mail... I will post some of the stuff here for others to read.
thanks Henry.
im at work now, and for some reason i cant check my email from here (company wont let me log onto my POP3, yet whenever i walk around the office i see all these desk jockeys logged onto hotmail lol :smile:).

Posted: Mon Jun 24, 2002 8:21 am
by Henry
On 2002-06-24 08:13, Dexter wrote:
On 2002-06-24 05:23, Henry wrote:
OK.. got the e-mail... I will post some of the stuff here for others to read.
thanks Henry.
im at work now, and for some reason i cant check my email from here (company wont let me log onto my POP3, yet whenever i walk around the office i see all these desk jockeys logged onto hotmail lol :smile:).
We got smart and blocked all hotmail accounts from our mail servers :smile:

Posted: Mon Jun 24, 2002 8:26 pm
by Dexter
any...um...updates? lol