Bootscreen mess

[AlexThestampede]

first of all,hi to everyone!i'm a new (proud)user of an Mx414,and i have immediatly started to mess it.i even created my own characters and bootscreen.tough i must've done something wrong when i uploaded it to the eeprom,because it's completly wrong.the first version had a logo done with my charachter and text,some of it scrolling.tough i had a messed logo,missing charachters in the text,and no scroll .wow.so i took away all the text,leaving only the logo.nothing to do.so i decided that the original one was sooo good looking(ehm....)and restored it.but,this is amazing....the logo is corrupted!and now it shows Matrix O rital!!!!!!!!and obviously the text isn't scrolling.sob.the program in the cd to upload screens won't connect,so i use lcdc to do that.there must be a way to upload a screen without having it messed up....
and another small thing,maybe not really related to the display...every time i connect my phone via irda to the pc,it opens the forum!!!what kind of problem could be this?i'm quite puzzled...lol

[Tom]

Hi Alex,

Thanks for posting.

Try sending the data twice, when you are trying to set up your start screen. Make sure you do not have another program that is trying to use the same com port or you won't be able to send data to the start screen. If you really want, I can send you the default memory settings, just email me at tlam@matrixorbital.ca.

If you have anyfurther questions or concerns, please feel free to contact me.

Best Regards,

[AlexThestampede]

Thanks for the help,tough i noticed that uploading the screen a few times "almost" works.Almost because it saves correctly only the first 4 custom chars,and the second 4 are distorted,like a wave effect.tough now my boot screen is good looking,and this problem isn't very bothering,i guess it should'nt work taht way...

[Martin Skibye]

Hey,
I know this is a (very) old thread, but I had the exact same "startup screen" problem and as many people are googling solutions, maybe this post would come to some usefulness anyway :-)

In this case I am using an LK204-25 but I reckon that the bootscreen memory issue goes for most of the display series.
I found that the reason why the display interface is messing up the bootscreen with funny characters is that the writing process to the non-volatile memory is too slow. This is indicated by the fact that the 40 char (4-line) display only had messy characters in the bottom line after first load of a new bootscreen and displayed perfectly after second load. A write cycle to the memory goes faster if no bit has to change state, therefore the second load of the bootscreen processes the first three lines a lot faster than the first load and consequently has time to do the last line correct.

The messy characters are the command chars from the subsequent commands. For some reason the display interface can't cope all the characters (In this case 40) at the present transmit speed and simply discards the latter ones (probably a buffer overrun). The outcome is that the interface never receives the 40 characters which it is expecting after the "Load Startup Screen" command has been called. Therefore the interface absorbs any succeeding character (including messy command-chars) until it has a total of 40 chars to build up the bootscreen.

>> THE SOLUTION is pretty simple. Avoid sending a whole string and instead chop it up and transmit single characters. After each transmission of a char insert a sleep. That's it. <<

In my case I had success with a sleep of 25ms which in this scenario introduces a latency of approx one second. A delay of this size is of absolutely no significance, since a bootscreen should only be loaded once (and not every time an app is started) for every new bootscreen-layout to avoid unintentionally using up the limited write cycles of the non-volatile memory.

Greetings & Salutations,
Martin Skibye