Suspect corruption of LK204-25 memmory

Gryphon · Post by **Gryphon** » Fri Mar 21, 2008 4:55 am

Hi All,

I wonder if anyone has had a similar problem and knows of a resolution. I have a LK204-25 with the extended temperature and supply voltage options.

At the moment when it is powered up without shorting the Manual Overide pins, the controller boots up with an unknown baud rate and nothing can talk to it. If I hold down buttons on the keypad that provide me with the manual over ride, the controller behaves as expected and I can talk to it.

I have tried reprogramming it from the uproject software after booting up with manual override. I have tried turning on remember and programing and using scripts but nothing works. Things like the user specified startup screen get saved and work but the baud rate always goes nuts.

The LCD is talking to a National Instruments controller and this did have some problems and I think at one point it threw a heap of stuff at the LCD and I am not sure if this corrupted the buffers. I definitely had the startup screen completely garbled after one such incident.

The behaviour I am describing now however is not due to the National Instruments controller or my software but is reproducible with uproject and a PC.

To recap, when the manual over ride button is held down, the controller starts up and communicates ok but if this is not done, it comes up with an unknown baud rate. The effect of this is that nothing inteligible gets read on the screen and the key presses do not get sent back correctly.

Please help!!

Thanks in advance.

Peter

Clark · Post by **Clark** » Mon Mar 24, 2008 11:42 am

Hi Peter,

Thanks for the question, sorry to hear that you have been having trouble communicating with your LK204-25 unit. I understand you've tried the manual override, but have had no success in getting the baud rate to stick. I know it seems repetitive, but the process can be a little confusing, so I'd like to give you some direction, and have you take another go at the override.

1. Can you confirm the PCB revision of your unit. These instructions will not work quite the same for anything other than PCB Rev. 2.0.

2. Remove power from the unit. Place the jumper on the R5 and C1 pins. Apply power once more.

3. Open up uProject and Autodetect the display. Try a simple backlight on/off command in the main tab to ensure good communication.

4. Open the remember tab, and turn remember on.

5. Open the uploader tab, expand the other command tree, and drag the raw data command into the command window.

6. In the raw data command line, enter the following string: /254//57//51/. Hit Ok, copy and past the command a couple times just to be sure it is executed, and finally execute the file.

7. Open the remember tab and turn remember off.

8. Remove power from the unit. Remove the override jumper. Apply power once more.

I understand you've tried the process, but I know it is confusing; we're working on improving this in new manual, and then trickling those changes down to old ones. The command line will set the baud to 19200, if you like something else, you can follow the same process to change it using the guide in the manual, just make sure the hex values give are translated to decimal (uProject will do it for you).

Let me know how that turns out, and I'll advise from there.

Thanks,
Troy

Gryphon · Post by **Gryphon** » Tue Mar 25, 2008 3:21 am

Hi Troy,

thanks for your response. I tried the steps exactly as you suggested. Here's what has been observed.

1. Autodetect does not detect the module even if the unit is powered up with the R1,C1 jumpered. If I open the port manually I am able to communicate with the module so this is probably not a big deal. I am using a USB to serial adaptor to talk to the screen. All functions in uproject work fine, sending text, clearing screen, setting backlight etc as long as the module starts up with R1C1 jumpered.

2. Doing the steps and then repowering the device does not fix it, it remains exactly the same as before.

3. When the unit powers up without R1C1 jumpered, the screen shows solid blocks in all 4x20 points. If R1C1 are jumpered, the screen powers up and displays the configured start up text. This is the behaviour with nothing plugged onto the comm port of the screen and so I am sure that this is nothing to do with any stray commands throwing the LCD out of whack.

The screen used to function ok and did not need R1C1 to be jumpered in order to function but now only works in this strange way. I have a plain vanillla (no extended temperature and voltage option) LK204-25 and it functions fine with the same hardware setup except of course I power it from a 5V source.

Is there some way for me to flash the module back to factory defaults? It seems to me that there must be 1 memory area where user settings get stored and this memory is defective or corrupted. As such the device can't start up properly reading data out of this area. When the R1C1 jumper is in place, it takes system defaults and works ok. What I can't understand is why the startup text is ok and does not seem to change but is displayed differently depending on whether R1C1 is jumpered or not. (Black full blocks when R1C1 not jumpered and proper txt when jumpered. No commands sent in between. Repeatable behaviour)

Really hope you'll be able to help, Troy as I can't really afford to send the module back as it is on a piece of gear that my customer has been waiting on for too long.

cheers!
Peter

Gryphon · Post by **Gryphon** » Tue Mar 25, 2008 3:22 am

Should also indicate that I have been using the latest available version of uproject and I redownloaded it before trying out your suggestions to be doubly sure!!

regards
Peter

Clark · Post by **Clark** » Tue Mar 25, 2008 11:07 am

Hi Peter,

Thanks for trying out the override again, I just wanted to make sure we had the easy fixes covered. On that note, I just want to confirm that you jumped R5 and C1, and that R1C1 is a bit of a typo.

With the additional description of the blocks on start up, I would definitely say you've managed to do some damage to the memory in that unit. Unfortunately, that usually means I'll have to re flash it back here, but I believe I can get you to try at least part of that process at your location.

I understand you are pressed for time, and don't want to send that unit back in, so I can email a .mem file to try to bring some life back to the display. Just send me a message at tclark@matrixorbital.ca using your account, and I can get that over to you right away.

Once you've got the file, open up uProject, go to main, hit initialize memory over on the right side, and point to where you've got the file saved. That will hardwire the factory defaults into the unit, and hopefully bring back some life.

Thanks,
Troy