INT 21h

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Raspberry Pi: your own chars on LCD connected with 74HC595

№ 6124 В разделах: Electronics Programming от March 31st, 2014,
В подшивках: Displays, Raspberry Pi

After you connected the display to your Raspberry Pi you want to start writing on it standard and non-standard characters. For non-standard characters in HD44780 controlers the special memory beginning with the address 0x40 and offering for loading of 64 bytes describing additional 8 characters.

8 bytes describe 5 columns and 8 lines on each character. Use this program for drawing.

In special program I drew the characters needed to me and with HEX editor saved in the file set1.map. File can be empty or the filled up to 64 bytes.

Get last version from https://git.blindage.org/21h/raspberry-pi-hd44780-via-74hc595 and put it to /opt/. After you compile program (if you need it) try ./lcd595out /opt/lcd/set1.map "`echo -e "Spec chars \x08\x01\x02\x03\x06\nHello"`".

Be carefull! Special chars have issues:
1) \x00 will not print your first special char, use \x08.
2) \x0A working as \n in my program, use \x02 instead.

My some 1-char pics:
0A04150E1F0E1100 – bug
0E1111150E020700 – hard drive
0E110E110E110E00 – disks
00000A0A00110E00 – smile happy
00000A0A000E1100 – smile sad
1F1213121B121F00 – chip\memory
0E040E1915110E00 – timer
000A0E1915110E00 – clock
1D171D011D171D01 – network

Multichar:
0011040E0E041504 0804141414140408 0E0404040E1F0000 – Wireless
0103070F0E0E0E0E0E0E0E0E0F070301181C1E060000000000000000061E1E1C000606000000000000000000000606001818180C0C0C0C060606060303030303 – Disk C
01070C0818101010101C0602030101010101010103061C1010101010180C07011F000000000E111111110E000000001F1F110E001D00140A1F041A0000000000 – Disk drive