Hello,
I am still toying with different ways of displaying numbers on an Adafrut 1.4'' TFT color display (still haven't found a way of doing that which satisfies the former web developer in me ).
Suppose I put an rgb565 bitmap into PROGMEM like this:
static const uint32_t zero565[225] = {
 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
 0xffffffff, 0xef7d738e, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00002124, 0xa5148c51, 0xffffffff,
 0xffffffff, 0xa5140000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x000039c7, 0x8c510020, 0x8c51ffff,
 0xffffffff, 0xffffc638, 0x21040000, 0x00000000, 0x00000000, 0x00000000, 0x18c36b4d, 0x4a490000, 0x73aeffff,
 0xfffff79e, 0x738e0000, 0x5aebffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffbdd7, 0x18e30020, 0x8410ffff,
 0xffffef7d, 0x632c0000, 0x4228dedb, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffb596, 0x18c30020, 0x8c71ffff,
 0xffffef5d, 0x5aeb0000, 0x528adefb, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffa534, 0x10a20841, 0x9cd3ffff,
 0xffffef5d, 0x528a0000, 0x5acbe71c, 0xffffffff, 0xffffffff, 0xffffffff, 0xffff9cf3, 0x10820861, 0xa514ffff,
 0xffffe73c, 0x42280000, 0x630ce73c, 0xffffffff, 0xffffffff, 0xffffffff, 0xffff9492, 0x08610861, 0xad75ffff,
 0xffffe71c, 0x39e70000, 0x6b6def5d, 0xffffffff, 0xffffffff, 0xffffffff, 0xffff8c51, 0x08611082, 0xbdd7ffff,
 0xffffdefb, 0x31860000, 0x73aeef7d, 0xffffffff, 0xffffffff, 0xffffffff, 0xffff7bef, 0x084110a2, 0xc638ffff,
 0xffffdedb, 0x212410a2, 0xce79ffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffbdd7, 0x18c310a2, 0xce79ffff,
 0xffffef7d, 0x4a69d6ba, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xad7552aa, 0xe71cffff,
 0xffffef5d, 0x4a49defb, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xad55528a, 0xef5dffff,
 0xffffce79, 0x08612124, 0xef5dffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffad55, 0x08412124, 0xef5dffff,
 0xffffce59, 0x08410000, 0xa514ffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffff528a, 0x00002965, 0xef7dffff,
 0xffffc618, 0x00000000, 0xa534ffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffff4a49, 0x00003186, 0xf7beffff,
 0xffffbdf7, 0x00000000, 0xad75ffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffdf4228, 0x000031a6, 0xffdfffff,
 0xffffb5b6, 0x00000020, 0xb596ffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xf7be39e7, 0x000039e7, 0xffffffff,
 0xffdfad75, 0x00000861, 0xbdd7ffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xef7d39c7, 0x00004228, 0xffffffff,
 0xffdfa534, 0x00001082, 0xbdf7ffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xe73c31a6, 0x00004a69, 0xffffffff,
 0xffdf9cf3, 0x00002965, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xdefb2965, 0x00005acb, 0xffffffff,
 0xffffffff, 0xd6ba2965, 0x00000000, 0x00000000, 0x00000000, 0x00001082, 0x632c5acb, 0x0000630c, 0xffffffff,
 0xffffa514, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x39c78c51, 0x00208c51, 0xffffffff,
 0xffffe73c, 0x630c0000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x39c79cd3, 0x94b2ffff, 0xffffffff
};
and then called it using this bit of code:
tft.setAddrWindow(50, 50, 68, 75);
for (int img = 0; img <= 225; img++){Â
   tft.pushColor(zero565[img]);
}
Right now, (obviously?) this isn't working, it sort of half looks like the number zero in a 7-segment font, as it is supposed to, but the image is somewhat garbled. But could it be made to work? I guess you'd somehow have to tell the display when a row and column starts and stops, right?
I am using an Atmega1284P-PU, so there's enough memory space on it to store an entire set of bitmaps for the numbers from 0 to 9. Per bitmap, these seem to take up around one and a half percent of the chip's program memory, so it'd be well manageable. And I would probably only be using this one font face.