This is an adaptation of the simple light-chasing demo, that besides running
the simple basic demo, also transfers the state of the 'lights' to a modbus
slave.

By default, it is configured to send to output bits 1, 2, 3 and 4, of RTU slave
with id 0, on the /dev/ttyS1 serial port (9600 baud, no parity, 8 data bits,
1 stop bit).


To start:
	cd demo/basic_modbus; make

To quit:
	press `Q' on the keyboard


It's controlled from the keyboard (module Kbd, kbd.c): the keys L, R and Q
on the keyboard toggle the three points `left', `right' and `quit'.

The Chaser module (chaser.c) is a primitive `light chasing' program. The
direction of movement can be changed using the `left' and `right' points;
these are notionally push-buttons, but in this demo they are controlled by
the L and R keys. The speed of the chaser can be configured with the
"delay" setting in the "Chaser" section of matplc.conf

The demo terminates when the `quit' point comes on (keyboard Q).


Buglet:
	- assumes a linux terminal (hard coded escape codes).