Raspberry Pi GPIO port to IDC26/DB-25 ribbon cable

Using a IDC26/DB-25 ribbon cable with the GPIO of a Raspberry Pi is quite useful. It fits perfect on the GPIO port. But there are 2 drawbacks:

• GPIO7 is not connected because DB-25 port has only 25 pins and Raspberry Pi’s GPIO port has 26.
• The pinout numbers on the DB-25 side does not match the pinout numbers in the GPIO side.

TL;DR: This is the pinout in the DB-25 side if you use a IDC26/DB-25 ribbon cable:

In case you want to know why look first at the pinout of the Raspberry Pi’s GPIO:

And now the pinout correspondence on both DB-25 and IDC26 side of the ribbon cable:

As you can see the pin 2 in the GPIO port corresponds to the pin 14 in the DB-25 port, etc. This are the functions of every pin in the DB-25 port if you use a IDC26/DB-25 ribbon cable with your Raspberry Pi:

1. 3.3V
2. GPIO2 (I2C)
3. GPIO3 (I2C)
4. GPIO4
5. GND
6. GPIO17
7. GPIO27
8. GPIO22
9. 3.3V
10. GPIO10 (SPI)
11. GPIO9 (SPI)
12. GPIO11 (SPI)
13. GND
14. 5V
15. 5V
16. GND
17. GPIO14 (UART)
18. GPIO15 (UART)
19. GPIO18 (PWM)
20. GND
21. GPIO23
22. GPIO24
23. GND
24. GPIO25
25. GPIO8 (SPI)

Raspberry Pi GPIO image by raspberrypi.org

http://es.wikipedia.org/wiki/Conector_IDC

http://es.wikipedia.org/wiki/D-sub