villaperros / pdwiringpi

Pure Data (pd) external for hardware I/O on a Raspberry Pi using wiringPi.

pdwiringPi

This repository contains an 'external' (plugin) for Pure Data to communicate with hardware on a Raspberry Pi using the wiringPi library.

This code should be assumed to be alpha-quality, it has been minimally tested but is under active development.

The main [wiringPi] object can act either as a generic wrapper for the library or can be bound to a specific I/O pin. In the pin-specific mode, a [bang] input will read the pin and a numeric input will change the pin state. In the generic mode, messages on the input are interpreted as function calls and are mapped to the supported library API calls.

If pd is run as root (e.g. using sudo), then the object uses the direct hardware API which is faster and more versatile. Without root permission, the object falls back to the slower and less capable /sys/class/gpio interface.

The object assumes that the wiringPi installation includes the 'gpio' program and will run it using system() if needed.

Compiling

System requirements: make, a C compiler, a Pd installation, and wiringPi.

A simple Makefile is provided for compiling directly on a Raspberry Pi:

make

Installation

There are two files to be installed:

1. the loadable module: wiringPi.pd_linux
2. wiringPi-help.pd

If compiled in-place, the build folder named pdwiringPi/ can simply be added to the pd load path. Or these files can be copied to an existing pd externals folder such as /usr/local/lib/pd-externals.