norbertkiszka / simplest-lpt-led-clock

Easiest led 7-segment display driver on LPT (printer parallel port) without any IC's or transistors. Shows time and data from a text file.

Required hardware

1. 4-digit 7-segment led display with common cathode (common anode is not supported).
2. Eight ~100 Ohm resistors.
3. Any wire to make 12 connections.
4. PCB or prototype board - eventually without it...
5. DB25 male connector - or simply put wires into lpt socket...

Conection

LPT PIN NUM ------ display
1 (STROBE)         Cathodes - digit 1 (pin 12)
14 (AUTO FEED)     Cathodes - digit 2 (pin 9)
16 (INIT)          Cathodes - digit 3 (pin 8)
17 (SELECT)        Cathodes - digit 4 (pin 6)
2 (D0)             A
3 (D1)             B
4 (D2)             C
5 (D3)             D
6 (D4)             E
7 (D5)             F
8 (D6)             G
9 (D7)             Dot

Photos

License

GPL V2 - included with repository in text format.

7-segment-4-digit-red-12-pin-pinout-1.jpg - this schema was taken from mklec.com and I'm not owner of it.