Velleman has introduced a new product that could be useful for home automation applications.
VM142 MINI PIC-PLC APPLICATION MODULE
http://www.velleman.be/es/en/product/vi ... id=370680#
"Now you can create your own custom application without the hassle of making the hardware. All the buffered inputs and outputs are ready-made for you. The module features on-board LED, a relay output and a buzzer."
* 9 free programmable I/Os (4 in-, 5 outputs)
* PIC16F630 microcontroller from Microchip® on-board
* LED indication for power supply and relay output
* 1 free programmable LED indication
* on-board mini buzzer for audible signals
* on-board ICSP™ connector for programming
* PIC™ programmer supports PIC16F630
This module looks quite promising for those who want some of their own PLC type controlling without needing to design their own hardware. The module seems to be reasonably priced (45-49 Euros) making it cheaper than many other commercial entry level PLCs on the market.
The good and bad on this is that you need/can program the PIC microcontroller in this product from ground up. There are some example source code for this product at http://www.velleman.be/es/en/download/files/ (both assembler and MikroBasic).
Seems to be interesting to test.
For easier programming for PLC functionality adapting software like "Ladder Logic for PIC and AVR" from http://www.cq.cx/ladder.pl could be one idea worth top try I think. It is a compiler that starts with a ladder diagram and generates native PIC16 or AVR code (unfortunately there is no ready setting for PIC model used in the VM142 kit).