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MAX7219 dot matrix degree symbol

Posted: 04 Feb 2023, 18:17
by SirWant
Hi!
Something is displayed before the degree symbol. I tried DotMatrix,txt,1,° DotMatrix,txt,1,° DotMatrix,txt,1,{D}
Font - Extended ASCII characters.
IMG_20230204_152115_copy_800x600.jpg
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Re: MAX7219 dot matrix degree symbol

Posted: 04 Feb 2023, 19:36
by Ath
The extra character is caused by the symbol being represented in unicode, a double-byte character set, but this plugin has support for an ASCII character set only, and doesn't use most of the special characters as listed on the System Variables page.
The degree character is not included in the default font that is used, but it is available in the "Extended ASCII characters" set, as available from the documentation for the plugin. The degree symbol is in position 186 of the Extended ASCII set, you could try to use '║' (hold down the alt key and type 186 on your numeric keypad) where you want the degree symbol.

The Extended ASCII set is probably not included in many builds, what exact build (name of the .bin file please) are you using?

Re: MAX7219 dot matrix degree symbol

Posted: 04 Feb 2023, 21:02
by SirWant
I use custom ESP32 4m316k with #define USES_P104

Re: MAX7219 dot matrix degree symbol

Posted: 04 Feb 2023, 21:21
by Ath
The Custom builds should have all fonts enabled, so you can select the Extended ASCII (4) font and use the '║' to display the degrees symbol.

Re: MAX7219 dot matrix degree symbol

Posted: 04 Feb 2023, 22:29
by SirWant
Oh. Thanks, only through transcoding to ASCII in Notepad++ does it work. And if you then make any changes through the interface - it breaks again :)

Re: MAX7219 dot matrix degree symbol

Posted: 04 Feb 2023, 22:41
by Ath
Did you try to use the ║ character instead of the degree symbol?

Re: MAX7219 dot matrix degree symbol

Posted: 04 Feb 2023, 22:56
by SirWant
I try alt 0176 (and 0150 for ndash).

Re: MAX7219 dot matrix degree symbol

Posted: 04 Feb 2023, 23:03
by Ath
SirWant wrote: 04 Feb 2023, 22:56 I try alt 0176 (and 0150 for ndash).
Please try alt-186, not alt-0176 or alt-0150, they will result in unicode characters again, that are not supported...

Re: MAX7219 dot matrix degree symbol

Posted: 05 Feb 2023, 00:10
by TD-er
Yep, the 4-digit codes are Unicode, the "old" alt-codes upto 127 are ASCII and upto 254 extended ASCII.
This latter group depends highly on the used code table.
The most frequently used ones in Dutch are: Alt-130, -137, -138 and 139 (é, ë, è, ï)
But in some regions, where another default code page would be used (e.g. for cyrillic characters) these could look completely different.
So that's why they came up with Unicode to finally have a coding schema for all possible characters... only to extend this also at some moment :)

Re: MAX7219 dot matrix degree symbol

Posted: 07 Feb 2023, 08:51
by bidrohini
Once I faced the same problem while using the MAX7219 dot matrix display with an AVR microcontroller. A garbage symbol was always showing. I finally removed that by making some modifications to the code.