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LK204-25 Stuck at Startup Display Matrix Orbital
Posted: Wed Jan 04, 2006 1:16 pm
by jason
We've got over 4 dozen of the LK204-25 Matrix Orbital Displays that we are using with a micro (hooked up with the I2C) and a keypad. Over time some displays (approx 2 dozen) have been locking up....and after they lock up....the next time you power it off then on, it gets locked up at the Bootup screen. Are these displays damaged or is there a way we can fix them or replace one or two components to fix them?
Thanks,
Jason
Posted: Wed Jan 04, 2006 1:57 pm
by Tom
Hi Jason,
Thank you for posting on the forum.
I have seen this problem before. Once the display locks up, the power needs to cycled, and it will work again. This problem seems to be noise related. What I've seen that has worked is to connect your keypad to the ground plane. You can also place some resistors in between the keypad and the keypad connector. Make sure everything is commonly grounded.
Try these suggestions, and let me know how things work out.
Best Regards,
Posted: Wed Jan 04, 2006 2:05 pm
by jason
No this happens after I remove power and then after that it never gets past the boot screen again.
Posted: Wed Jan 04, 2006 2:50 pm
by Tom
Are you able to communicate with it via RS-232 after?
Posted: Thu Jan 05, 2006 5:40 am
by jason
No I am not able to communicate.....it stays at the Matrix Orbital Screen. Could the RS232 chip taken a hit or the programming for the display?
Posted: Thu Jan 05, 2006 9:32 am
by Tom
John,
How did you communicate it via RS-232? Can you try it with your pc, and the use the program called uproject, which can be downloaded at
http://www.matrixorbital.ca/software/so ... /uproject/
Posted: Thu Jan 05, 2006 11:49 am
by jason
Ok, I've got the displays to work through the RS232, however with our micro's, we communicate with the I2C port. This may have taken a hit?
Posted: Thu Jan 05, 2006 2:53 pm
by Tom
Jason,
I was checking if the pic was still working. It is strange that you will have 2 dozen lock up like that. I suspect the culprit to be noise related. Have you tried communicating via I2C again after communicating via RS-232? How fast are you communicating with the display at on I2C?
Have you also checked your communication signals after the lock up? It looks asthough it may also be an issue with the instructions of your processor. If you communicate too fast to the display, you may get a lock up.
Posted: Wed May 31, 2006 1:15 pm
by erv100
jason wrote:Ok, I've got the displays to work through the RS232, however with our micro's, we communicate with the I2C port. This may have taken a hit?
Jason . I have exactly the same problem. What did you do to get it running with RS232 ?
Thx
Erv
Posted: Wed May 31, 2006 1:50 pm
by Raquel
Hi erv,
A suggestion, please make sure that your board is set to RS232 when you try and communicate with it via RS232.
Try hyperterminal or our own uProject to communicate with the module.
Posted: Wed May 31, 2006 2:12 pm
by erv100
Hi Raquel,
(hope this is not a repost, the application failed before).
How do I switch the Display to RS232? I have the RS232 signal connected to the lower middle white 4 pin connector.
Thx
Posted: Wed May 31, 2006 2:47 pm
by Raquel
Is it possible for you to post a picture of your module? What is the PCB rev?
Posted: Wed May 31, 2006 3:06 pm
by erv100
Here we go, The pics are attached. The Rev is 1.23
Thanks
Erv
Posted: Wed May 31, 2006 3:13 pm
by Raquel
Sorry, Erv, but I do not see any picture.
Posted: Wed May 31, 2006 3:24 pm
by erv100
I try again. The Pics must have been to big. (2 Pics total).