Having recently bought an old house, I Had to entirely rebuild the electrical circuitry. So I decided to include some automation. As the goal was to manage every Lamp and every switch in the house, the most important think was to build something stable, So I decided to use Industrial PLC based on hte Brand IMO (http://www.imopc.com), mainly for a reason of global cost.
It's based on 5 IMO ISMART (http://www.imopc.com/pages/spotlight_ismart) PLC's wich collect the switchs and pilots the lamp with they internal relays. Each ISMART manage a group of 16I/O and the 5 ISMART are linked by a MODBUS and drived by a Master (IMO i3 : http://www.imopc.com/pages/spotlight_i3Microsite) that handle any intelligent action. In case of any problem with Modbus or with the master , any slave is still autonomous to drive the SWITCH ON / SWITCH OFF actions .
Be sure that this point is *very *important to keep the ambience cool enough en in the house ... 8)
To add some more functionalities, I've add a 6th slave to this bus by using an Arduino, it was a bit tricky with hte modbus library but finaly works pretty well, as lon as you keep the speed of the bus low enough, arduino is not a Ferrari I guess....
This systems works well for 3 years now but I've decided to improve it by adding Internet connectivity, this is where Mango takes place !
For that, I use a second Modbus in my i3, so that Mango polls the i3 and can then read/write to it's registers and therefore acts on all the ISMART of the house. I can also push some weather datas to Pachube.
I had many problems to do that, mainly because of the instability of the Modbus beetween the i3 and the Mango (installed on a ALIX board by the way).
It works now but is a little bit instable for a reason I ignore (CRC problems / Excepetions errors ...).
So that's it. I would be glad to share this with other people that did similar experiences (Sure this Forum is plenty of !) and if possible avoid the traps i ran into.
But first of all I would like to thanks all the persons that works on the Mango project, It's very human affordable and powerfull enough to add some nice functionalities to a home automation project !!
(mango [at] airtune [dot] info )