LK204-25 Stuck at Startup Display Matrix Orbital

jason · Post by **jason** » Wed Jan 04, 2006 1:16 pm

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

Tom · Post by **Tom** » Wed Jan 04, 2006 1:57 pm

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,

jason · Post by **jason** » Wed Jan 04, 2006 2:05 pm

No this happens after I remove power and then after that it never gets past the boot screen again.

Tom · Post by **Tom** » Wed Jan 04, 2006 2:50 pm

Are you able to communicate with it via RS-232 after?

jason · Post by **jason** » Thu Jan 05, 2006 5:40 am

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?

Tom · Post by **Tom** » Thu Jan 05, 2006 9:32 am

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/

jason · Post by **jason** » Thu Jan 05, 2006 11:49 am

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?

Tom · Post by **Tom** » Thu Jan 05, 2006 2:53 pm

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.

erv100 · Post by **erv100** » Wed May 31, 2006 1:15 pm

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

Raquel · Post by **Raquel** » Wed May 31, 2006 1:50 pm

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.

erv100 · Post by **erv100** » Wed May 31, 2006 2:12 pm

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

Raquel · Post by **Raquel** » Wed May 31, 2006 2:47 pm

Is it possible for you to post a picture of your module? What is the PCB rev?

erv100 · Post by **erv100** » Wed May 31, 2006 3:06 pm

Here we go, The pics are attached. The Rev is 1.23
Thanks
Erv

Raquel · Post by **Raquel** » Wed May 31, 2006 3:13 pm

Sorry, Erv, but I do not see any picture.

erv100 · Post by **erv100** » Wed May 31, 2006 3:24 pm

I try again. The Pics must have been to big. (2 Pics total).