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weirf LCD behavior...


pilo

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I buy a 2x40 LCD on ebay (I will ask for the datasheet), with a HD44780 chip. I plug it on the core and... It works, but some character are not the right one! 0 (zero) is a bold 'i', the x, a, p, l, e (lower case) are some weird character (I look at the HD44780 datasheet, and didn't find all of them!). the lower case 'm' is correct. All the Upper case are correct (I think, I test running the AIN example 2).

Any idea??? I check the wiring manytimes, but I may be made a mistake (with no datasheet, I only found a wiring on a forum)...!

P.S. : with a 2x20 LCD all is working

thanks!

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huuummm yes... :-/

is it possible to test them with a MIOS test program (or should I write this one?)

But I think it's weird that it display 1,2,3,4,5,6,7,8,9 but not 0?

In the hd44780 datasheet, somme of the character are in the A02 eprom, this would agree what you said?

By the way, they've got no backlight... I didn't think it was a drawback when I order them (they were "cheap"), but it's make about 4hour that's I'm looking for a way to add this... and I think it's impossible... if anyone as an idea, tell me, but I'm now looking for other LCD!

thanks Thorsten! I think I'm going to test all the character that can be displayed!

(my midibox LC is growing and working well ;)... with a 2x20 LCD...)

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huumm so I look closer to the hd44780 datasheet, and with the japanese character set (rom code A00) the a,b,c,d,e... ect Lower and Upper Case have the same code as in the european character set (rom code A02)... so?

I re-check my wiring, and it's seems to be good, but I think if I made a mistake on the data bus, there will be other errors, no?

Well, I try to make a test program, but it's hard because i use Emacs, gpasm, perl under linux, and then I have to boot under windows to send it with MIOX... I will be happy when the java client for uploading apps will be finish :$

And is there any way to get the display brighter? I test with putting some led in front of it but it's make no difference... I'm asking why LCD with no backlight exist!

By the way, thanks Thorsten, because it's very easy and interesting to work with MIOS ;) ;D

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Hi Pilo,

I've no idea how to make the LCD brighter... :-/

Yes, you could try to find out the exchanged data lines by printing different chars. I can suggest two solutions:

If you like the Unix feeling (like me! :-)), just install Cygwin (http://www.cygwin.com), this is a nearly complete Unix environment running under Wintendo. Perl and Emacs are part of the standard release (the setup program  allows you to select all the programs which you would like to use, thereafter the appr. packages will be downloaded and installed automatically)

Another, maybe faster solution for the first tests: you are able to execute any function via MIDI by using the debug feature which is integrated into MIOS.

I just have inserted this tool into the MIOS release

http://www.ucapps.de/mios/mios_v1_3.zip

(debug/mkdbg.pl)

Examples:

Search in mios_vectors.inc for the address of the appr. function. Or search in the .lst file if an application function should be executed. Run the mkdbg.pl script with the appr. parameters and send the generated SysEx string to the core.

clear the display - the address of MIOS_LCD_Clear is 0x2d04. Start the mkdbg.pl script with following parameters:

perl mkdbg.pl exec MIOS_LCD_Clear.syx 0x2d04 0x00 0x00 0x00 0x00
Print a character (here: 0x40 = @) - the address of MIOS_LCD_PrintChar is 0x2d28:
perl mkdbg.pl exec MIOS_LCD_Char.syx 0x2d28 0x40 0x00 0x00 0x00

Hope that it still works ;-)

Best Regards, Thorsten.

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Oooohhh yes!!! thanks ;D

I only unix like feeling ;) I have test cygwin some times ago... but it's still windows....:(

Oki I 'm going to make my midi port works under linux (with alsa, i have still some problem with...) and test the LCD via function! I think it's the easiest way to test it! (because writing a test program will take a lot of time, as I don't know asm very well.... only x86)

I'm going to work on this NOW!

THANKS!!!!  ;D

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I've the same problem with ALSA. But since I own the MBHP_USB, I'm able to use MIDI again :)

I just noticed that the debug function has a bug - the working register (WREG) will not be written correctly, you will see a "-" instead.

I will fix this and I will write an upload script for MIOS .syx files, so that it is possible to update the new code under Linux.

Best Regards, Thorsten.

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huuummm you're faster than me!

I just discover that the midi port works, it's only that the SB128 (CT5880) has got no synthetizer on it. I test it with pmidi + midibox and it works.

I come here to ask you how sysex is send to the midibox to write a quick code to do it! I need to upload MIOS V1.3...

Still with linux : why I get error on the IF*** macro with gpasm? (in the doc it says that it can compile code for pic18f52...)

Thanks! ;)

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It's also my new toy ;-)

The updated version can be found here:

http://www.ucapps.de/tmp/mios_upload_b.zip

Unfortunately the return messages of a debug command will not be received (too fast) - possibly I've to rewrite the receive handler so that input and output streams are handled in parallel. However, something for the next days...

Best Regards, Thorsten.

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