#define ________ 0x00
#define _______A 0x01
#define ______A_ 0x02
#define ______AA 0x03
...

uint8_t charmap[] = {
    // '+'
    ________,
    ___AA___,
    ___AA___,
    _AAAAAA_,
    _AAAAAA_,
    ___AA___,
    ___AA___,
    ________,
    ...
};