I'm using SevenSegNumFonts in my sketch since they are the only one big enough for my need. Problem is there are only numbers. I would like to add some characters like + - and maybe a few letters. This seem fully possible when I look at the DefaultsFonts.c file. But what is the most practical and easy way to do it? I understand that the two first bytes in the array is the size of the font (3250 or 0x200x32). But what are the next two? Then for the data must I manually draw pictures of the character and figure out very data byte in that way? Maybe someone have already done this?
You have a couple of options:
- make your own font file using the convertor available here Electronics - Henning Karlsen. I did start to play around with this some years ago but it all got too hard.
- use one of the alternative font files created by other users - you should be able to find something acceptable here Electronics - Henning Karlsen.
If you think about it, you will probably realise that producing a '+' on a seven segment display font is not really possible 
Cheers
Magicj:
You have a couple of options:
- make your own font file using the convertor available here Electronics - Henning Karlsen. I did start to play around with this some years ago but it all got too hard.
- use one of the alternative font files created by other users - you should be able to find something acceptable here Electronics - Henning Karlsen.
If you think about it, you will probably realise that producing a '+' on a seven segment display font is not really possible
Cheers
But in my case with 3.2" TFT display I don't really have seven segment display. And one of the available fonts under your suggested url was SevenSegmentFull which has other characters and letters. Happy I didn't have to manually figure out bytes in an array.
EDIT but I have discovered that not all letters are possible
jfri:
EDIT but I have discovered that not all letters are possible
Nor is a '+' sign