Problem with LCD2041

[JacquesB]

Hi,
I have a problem with a LCD2041 mainly regarding Auto Scroll.
I've used the LCD2041 rev 1.3 hooked up to a microcontroller that sends formatted
info on the display. I've bought lately 4 more displays that came at revision 2.0.

After searching for missing characters that could explain why the 1st row was always
missing I found out that on this version there is an Auto Scroll that is setup by defalt to ON.
If I send 254 82 it solves the problem but reappears after power up.

I've tried to send :
254 147 1 ( Set Remember) followed by
254 82 ( auto scroll off)
power OFF then ON
and the auto scroll still ON at power up

Is there a sequence or something that I'm missing

BTW: I cannot change the startup message from "Matrix Orbital" to something else using the command 254 64 char char ... ! Have any clue ?

Thanks

[Clark]

Hi Jacques,

Sorry to hear you've been having a little trouble saving some settings on that LCD2041. The first thing I see is that remember is not turned off; you'll want to issue that command after you're done saving settings to preserve the write cycles of memory; approximately 100,000.

After that, you may want to take a look at the data lock features of the display to make sure nothing is locked down. I believe 254 213 245 160 0 should do the trick to unlock it, but have a look in the documentation to be sure.

Hopefully that data lock will help the start menu as well, also, make sure you send out all eighty (80) characters for the screen.

If you do have any more trouble, please just let me know.

Thanks,
~Troy

[JacquesB]

I'll try that next week and keep you updated

Thanks,

[JacquesB]

Hi,
I've tried to 1st unlock the display , set the remember ON, send the command and turn remember back OFF
and still at power up the scroll function is still ON !

254 202 245 160 0 ( Unlock according to manual ver 2.0)
254 147 1 ( remember ON)
254 82 ( Auto scroll OFF)
254 147 0 ( remember OFF)

BTW, I've also tried 254 213 245 160 0 as mentioned by you without any success.
The communication link is working ( characters typed on the PC are displayed on the LCD)
The clear screen command works ( 254 88)

What else am I missing ?

[quote="Clark"]Hi Jacques,

Sorry to hear you've been having a little trouble saving some settings on that LCD2041. The first thing I see is that remember is not turned off; you'll want to issue that command after you're done saving settings to preserve the write cycles of memory; approximately 100,000.

After that, you may want to take a look at the data lock features of the display to make sure nothing is locked down. I believe 254 213 245 160 0 should do the trick to unlock it, but have a look in the documentation to be sure.

Hopefully that data lock will help the start menu as well, also, make sure you send out all eighty (80) characters for the screen.

If you do have any more trouble, please just let me know.

Thanks,
~Troy[/quote]

[Clark]

Hi Jacques,

Sorry to hear that you are still having trouble with the auto scroll function on that LCD2041 unit. If you could, please check to see that row 5 and column 1 of the keypad are not shorted. Also have a quick look to see that no data is being sent on start up that could change the settings, maybe even put an oscilloscope to the data lines if possible.

Thanks,
~Troy

[JacquesB]

Hi Troy,

Are you sure that there is a keypad interface on an LCD2041 ? I don't see anything related to keyborad in the manual.

Also, I've captured all transactions between my microcontroller and the display. There are only "set cursor position" commands and Ascii characters to be displayed. The fourth line makes the display to scroll. If I send 254 82 it solves the problem but reappears after power up....

thanks
Jacques

[Clark]

Hi Jacques,

Sorry about that, my mistake, you'll be looking for a two pin jumper near the middle of the board. Just take a multimeter to those pins to make sure they aren't touching.

Thanks,
~Troy

[JacquesB]

I just found out that I had left a solder bloob on one of the TTL jumper pads. During the search process I'd configured the display for TTL inputs and then back to RS232. It seems that even with one of the TTL jumpers left I could transmit characters to the display but some of the commands were not understood.
The auto-scroll problem existed before i did try the TTL jumpers. So I probably succeeded to reprogram the display for No-scroll but the jumper-left in caused the scrolling. I'll try to reprogram the 3 other displays when I get my hand on them

Thanks
Jacques

[Clark]

Hi Jacques,

Good to hear you seem to have found the source of your scroll saving trouble. Best of luck with the other three, things should go a little smoother there. If you do run into any more trouble, please just let me know.

Thanks,
~Troy