Mounting the roller shutters

Based on a quick scan of my blog it may seem like HomeAutomation / Domotica is all about software and soldering – but it isn’t.  First you have to have the right hardware you want to monitor and/ or control. The roller shutters I installed during the last weekend didn’t need a single line of code 😉

Roller shutters

Roller shutters
Roller shutters

Roller shutters

Drilling holes, using the hacksaw and other ‘power tools’ were needed to create the right ‘setting’ to be able to add another feature to my Domotica system: controlling 12 roller shutters. I installed 8 of them during the last weekend.

After the first rolling shutter I (ever) installed and where everything was new and checked over and over again, the remaining 7 roller shutters were installed with an average time needed of 1- 1.5 hours each. Just do it, I’d say. Once you’ve managed to install the first one, the rest becomes easier and easier.

Last evening I started working on integrating those first 8 roller shutters into my Domotica system. First I had to be able to control the roller shutters with my 16-channel Somfy RS485 RTS Transmitter. For that I used a Somfy Telis-1 remote to get the roller shutter into programming mode and sent a command to the RS485 transmitter so that it would transmit something on the channel on which I wanted to control the roller shutter.

One thing to keep in mind when you’re programming the roller shutters, is that you have to do this one at a time: remove the power from all the roller shutters except the one you’re going to program. If you don’t, you’ll be programming multiple roller shutters at the same time, probably resulting in one big mess!

After that I did some tests from my own system. Cool, the roller shutter started moving. Now it was time to upgrade the touchscreen GUI with a few up- and down buttons. Just 1 line of code was enough for each button to control the roller shutter – a simple XMLRPC call to my system did the job.

And again, total integration of a complete new ‘sub-system’ within a few hours after it was installed… I love it!

Roller shutter events

Touchscreen GUI







Roller shutter Status view

Controlling roller shutters

6-7 years ago we installed a roller shutter at the window of our sons bedroom. Main reason was to keep his bedroom cool during the summer, but also to make it really dark in there if it was necessary. Roller shutters are very good at keeping the heat out during the summer, but they can also improve isolation during the winter. And of course, they create a delaying barrier for uninvited guests.

So for this year we decided to install roller shutters on almost all of our windows; both up- and downstairs.  This resulted in a total of 12 rolling shutters. Yep, that’s a lot…

So, how are we going to control all these roller shutters? With 12 remotes? Neh. With 1 remote, where you first have to select the shutter you want to control with an average of 6 button clicks? Nope. And where it’s hard to control variable groups of roller shutters at the same time with 1 click of a button? No. Or only lower the shutters that are located on the south side of the house? No! Sounds like horror, home automation-wise..

It does cost a lot of money to automate 12 roller shutters, but I’m sure that if we want to really use these roller shutters efficiently, there has to be some sort of automation involved. And I don’t just say that because I like to automate things 😉

Somfy has a wide range of products to control awnings, blinds, garage doors and roller shutters. Either by wall mounted controls, remote controls; the 3rd option is the Somfy RS485 RTS Transmitter:

This transmitter is not only for roller shutters; it can also be used to control other products like screens, curtains, blinds etcetera. This 16 channel 433 MHz transmitter has a RS-485 to connect this transmitter to non-Somfy systems (like mine), the protocol is well documented, so nothing stands in the way to integrate our dozen roller shutters.

Being the impatient one, I already have this transmitter for a week while the roller shutters have been ordered today – and the software interface is already finished for as far I can see without being able to do a hardware test. Cause the protocol is relatively easy, it didn’t take very long to write the code.

The RS485 protocol works with variable length frames which look like this:

Somfy RS485 frame

Message ID, ACK bit, frame length, node type, source & destination address, payload and checksum. That’s it. Defining this in Delphi could look like this:

  TSomfyNodeID = array[1..3] of byte;
  TSomfyNodeType = byte;
  TSomfyFrameData = TDynByteArray;
  TSomfyChecksum = word;

  TSomfyFrame = class(TObject)
    _MSG : byte;
    _ACKLEN : byte;
    _NODETYPE : byte;
    _SOURCE : TSOmfyNodeID;
    _DEST : TSOmfyNodeID;
    _DATA : TSomfyFrameData;
    _CHECKSUM : TSOmfyChecksum;

  TSomfyRXFrame = class(TSomfyFrame)
    function Validate:boolean;
    constructor Create(const RawData:String); virtual;
    property Valid:boolean read Validate;

An additional ≈200 lines of code and the interface is finished; another 30 lines of code for the ‘RollerShutter’ device class and everything is in place to control the roller shutters from my system: triggered by events, with our own remotes,  touchscreens – whatever we want.

Can’t wait!