piface

piface is an erlang application for controlling a Piface board (a Raspberry Pi io extension).

Dependencies

To build piface you will need a working installation of Erlang R15B (or later).
Information on building and installing Erlang/OTP can be found here (more info).

piface is built using rebar that can be found here, with building instructions here. rebar's dynamic configuration mechanism, described here, is used so the environment variable REBAR_DEPS should be set to the directory where your erlang applications are located.

piface also requires the following applications to be installed:

• spi - https://github.com/tonyrog/spi
• gpio - https://github.com/Feuerlabs/gpio

Download

Clone the repository in a suitable location:

$ git clone git://github.com/tonyrog/piface.git

Build

Rebar will compile all needed dependencies.
Compile:

$ cd piface
$ rebar compile
...
==> piface (compile)

Run

piface is started in a standard erlang fashion:

$ erl
(node@host) 1> application:start(piface).

API

The following interface functions exist:

• init_interrupt
• gpio_get
• gpio_set
• gpio_clr
• read_input
• read_output
• write_output

For details see the source code documentation.

Documentation

piface is documented using edoc. To generate the documentation do:

$ cd piface
$ rebar doc

The result is a collection of html-documents under piface/doc.