User Manual

Chapter 8. I/O API
The Bluegiga I/O API defines how to access Access Server’s LEDs, buzzer, and general purpose
I/O.
8.1. Led and Buzzer API
Access Server’s LEDs and buzzer can be accessed through the /dev/led device. You can check
the status of the LEDs and the buzzer with the cat /dev/led command and set LEDs or the buzzer
with the echo abcde > /dev/led command. An upper case letter means that the LED or buzzer
is ON, a lower case letter means that the LED or buzzer is OFF. Letter "a" is the buzzer, letters
"b".."e" are LEDs 1..4.
Example:
[root@wrap /] echo abCDe > /dev/led
8.2. GPIO API
The Digital I/O pins of Access Server can be controlled write-only by using the /dev/io device
in the same way as the /dev/led device for LEDs and buzzer described above.
The letter-to-I/O mapping of the 16 pins is as follows, when looking at the connector:
hgfedcba
Xijklmno
X is the ground pin (and cannot be set).
o is the voltage sense pin (user can use any voltage from 3.3V to 5.0V).
The I/O must first be enabled by using the echo Z > /dev/io command. After that, pins can be
driven up by echoing the corresponding upper case letter (A-N) or down by echoing a lower
case letter (a-n) to the /dev/io device.
Example:
[root@wrap /] echo ZaBcD > /dev/io
118