/pi-plates-java

Java library to drive PiPlates (http://pi-plates.com/), a data acquisition and control set of shields for Raspberry Pi.

Primary LanguageJavaGNU General Public License v3.0GPL-3.0

Pi Plates library

A library to interact with Pi-Plates using Java.

Pi-Plates are a family of stackable and interchangeable add-on circuit boards that allow you to interact with the outside world using your Raspberry Pi (http://www.pi-plates.com).

Requirements

Since this code uses the Pi4J library to control GPIO pins and the SPI bus, which interacts directly with the SoC's registers, your code must run as root for now.

For the same reason you cannot just run it on your development PC. Pi4J uses the native WiringPi library (http://wiringpi.com/) which is compiled for ARM and will not run on x86 processors.

I recommend creating a script to build your code locally, transfer it to your Raspberry Pi and start a JVM with remote debugging enabled. Most IDEs will give you the exact parameters to use on your JVM.

Usage

The library implements two classes that act as interfaces to the two types of Pi-Plates currently supported:

  • com.nahuellofeudo.piplates.daqcplate.DAQCPlate
  • com.nahuellofeudo.piplates.DIGIPlate
  • com.nahuellofeudo.piplates.relayplate.RELAYPlate
  • com.nahuellofeudo.piplates.relayplate.RELAYPlate2

You interact with a plate by creating an instance of the corresponding class and passing the plate's address to the constructor. For example, to interact with a DAQC-Plate configured on address 2, you would do:

// Initialize plate interface
DAQCPlate daqcPlate = new DAQCPlate(2);

// Interact with the plate
double hardwareVersion = daqcPlate.getHWRev();
double softwareVersion = daqcPlate.getFWRev();
int analogValue = daqcPlate.getADC(adcChannel);

The code includes synchronization primitives to avoid SPI bus collisions if multiple threads try to communicate at the same time, even with different plates.

The interfaces themselves are modeled following the same patterns as Pi-Plates' own Python library, although some methods and parameters have been renamed to follow Java naming conventions.

All methods include Javadocs with short descriptions of what they do and how to use them.

Installation

The library has not yet been published and is currently considered experimental.

This is the first public release of this code, so expect the interfaces to change slightly in future releases.

Known bugs and limitations

Only DAQCPlate, DIGIPlate, RELAYPlate, and RELAYPlate2 are currently supported.

License

The code is licensed under the GPL license (https://www.gnu.org/licenses/gpl.txt)