This is a handy utility that goes well with the original fontconvert tool provided by Adafruit for converting TTF fonts to Adafruit_GFX .h format.
This utility tool provides the ability to generate an Adafruit_GFX .h format from an image file.
e.g.
pxfnt HD44780.bmp -o HD44780.h -f 32 -l 255 -w 5 -h 10 -F -i 3 -g v -H 1 -V 1 -x 1 -y 1
Glyphs range from ASCII code 32 -f 32 to ASCII code 255 -l 255.
Each glyph has a maximum width of 5 pixels -w 5 and a height of 10 pixels -h 10, with a fixed width of 10 pixels -F.
Color index 3 -i 3 is used for pixel data, with a default value of 1.
Glyphs in the image are arranged top to bottom, left to right -g v.
Glyphs are spaced 1 pixel apart horizontally -H 1 and 1 pixel apart vertically -V 1.
The glyphs begin 1 pixel from the left -x 1 and 1 pixel from the top -y 1 of the image.
Insoft Adafruit GFX Pixel Font Creator version, 1.0.8 (BUILD A0I87-25B5)
Copyright (C) 2024-2025 Insoft. All rights reserved.
Usage: pxfnt <input-file> [-o <output-file>] -w <value> -h <value> [-c <columns>] [-n <name>] [-f <value>] [-l <value>] [-a] [-x <x-offset>] [-y <y-offset>] [-u <value>] [-g <h/v>] [-s <value>] [-H <value>] [-V <value>] [-F] [-i] [-v]
Options:
-o <output-file> Specify the filename for generated .bmp, .h or .hpprgm file.
-w <value> Maximum glyph width in pixels.
-h <value> Maximum glyph height in pixels.
-c <columns> Number of glyphs per column when generating a glyph atlas.
-n <name> Font name.
-f <value> First ASCII value of the first character.
-l <value> Last ASCII value of the last character.
-a Auto left-align glyphs.
-x <x-offset> X-axis offset where glyphs start within the image file.
-y <y-offset> Y-axis offset where glyphs start within the image file.
-u <value> Cursor advance distance in the x-axis from the
right edge of the glyph (default: 1).
-g <h/v> Set the glyph layout direction, horizontal or vertical.
-s <value> Cursor advance distance in the x-axis for ASCII
character 32 (space), if not using fixed width.
-H <value> Horizontal spacing in pixels between glyphs.
-V <value> Vertical spacing in pixels between glyphs.
-F Use fixed glyph width.
-2x 2x glyphs when generating a glyph atlas.
-3x 3x glyphs when generating a glyph atlas.
-4x 4x glyphs when generating a glyph atlas.
-i <value> The color index used to represent a pixel in a glyph when using
a non-monochrome image, for monochrome image value is 0 or 1.
-v Enable verbose output for detailed processing information.
Verbose Flags:
f Font details.
g Glyph details.
Additional Commands:
pxfnt {--version | --help}
--version Display version information.
--help Show this help message.
pxfnt HD44780.h -o HD44780.hpprgm
The HP Prime stores its data as a list of 64-bit unsigned integers. The bitmap, however, is stored in a specific bit order (little-endian) and where each byte of the 64-bit value is mirror-flipped.
e.g.
01101100 #6Ch to 00110110 #36h
11111110 #FEh to 01111111 #7Fh
11111110 #FEh to 01111111 #7Fh
11111110 #FEh to 01111111 #7Fh
01111110 #7Eh to 01111110 #7Eh
00111000 #38h to 00011100 #1Ch
00010000 #10h to 00001000 #08h
00000000 #00h to 00000000 #00h := #00081C7E7F7F7F36:64h
#00081C7E7F7F7F36:64h
#--YYXXAAHHWWOOOO:64h = #--:8h #00:8h #00:8h #00:8h #00:8h #00:8h #0000:16h
#3CFEFEFE7E381000:64h
#--0000WWHHAAXXYY:64h = #--:8h #0000:16h #00:8h #00:8h #00:8h #00:8h #00:8h
Note
The only image file format currently supported by this utility tool is the Portable Network Graphic (8-Bit PNG), Portable Bitmap (PBM) P4 and Bitmap (BMP) format.