Nano Breadboard Interface

Introduction
This page describes a HomeEasy management interface using a breadboard, an Arduino Nano 3.0, and the Maplins VY48 transmitter (AM-RT4) and receiver (AM-HRR3) pair. This hardware combination allows further changes to be made to the physical design, and also provides a permanent serial connection for a similar cost to a dedicated FTDI cable + stand-alone components.

Overview
Code runs on the Nano that uses the AM receiver to listen for incoming HomeEasy signals. When signals are received they are decoded and written out to the serial line. At the same time the serial line is monitored for incoming 'commands', these are encoded into HomeEasy signals and send out by the transmitter. Perl scripts on a Windows or Linux PC then manage the sending and receving of HomeEasy commands via the serial line.

Hardware
The key hardware components are:
 * red jumpers are to +5V (sourced from the Nano)
 * yellow jumpers go to GROUND (sunk to the Nano)
 * the purple jumper connects the receiver DATA IN to Nano analog pin A1
 * the green jumper connects the transmitter DATA OUT to Nano digital pin D3 (used in analog mode)
 * the unattached red and white wires coming vertically off the board are the antenna for the transmitter and receiver respectively
 * there are LEDs on analog pin A3 and A5, going to ground through resistors

Note that the transmitter uses columns 4 and 6 to get GROUND/Vcc, and these appear to be used by the receiver chip, but there are no actually no receiver pins in these positions.

Software
The following software is available from the Nano breadboard code page:
 * 1) hemanager.pde (and hemanager.h) -- Arduino sketch that sends/receives wireless HomeEasy messages, and communicates with a PC via the serial port
 * 2) helink.pl -- Perl script that communicates with the hemanager using a serial port. Listens on a UDP port for commands to send to the device, all data coming back from the device is written to a logfile.
 * 3) hesend.pl -- Perl script that sends HomEasy on/off commands via UDP commands to helink. Allows HomeEasy signals to be sent from the command line, for example:

hesend.pl -cmd A120      // send OFF command to group A, unit 12 hesend.pl -cmd F141      // send ON  command to group F, unit 14

Limitations
There are a number of known limitations:
 * currently uses the 'Simple' (or 'Basic') protocol only. Support for Advanced protocol is not planned (author only has a HE-200 remote!)
 * serial port communication is not fast, and may be subject to timing related problems.
 * breadboard layout may require some fine-tuning