I've spent part of Christmas and the new year refurbishing our stairs (more about that later) - they turned out very nicely indeed.

But now on to the electronics part of this.

- Every step will have a (visually hidden) LED strip under the edge of the step, all connected to a JeeLabs LEDnode, and triggered by another Jeenode with a PIR sensor hanging over the steps (hidden among books on a bookshelf).

So far I have written the necessary software to test the coverage and response time of the motion sensor, and written the necessary routines for the LED node to be triggered by the home monitoring server.

This should be fun.

I've tried to do some further analysis of the problems I have with the FHT80B wireless thermostats - and the interference from the Jeenodes in the house.

As I have mentioned before I store all read ins from all the house sensors in a memcached instance on one of the servers - and for the FTH80B's it looks like this (after I throttled the Jeenodes sending frequency)

It basically shows that the last time I heard from the FHT80's was 55 seconds ago for the conservatory thermostat, and 99 seconds from the living room one.

It is also clear from this that the actuator values are send frequently - the rest only less often.

I have a problem with the house monitoring system - it looks like I'm a victim of interference

If you look at the graphs for our FHT80B radio thermostats you will notice something missing :

There is not red line (temperature readings) for the top graph (Concervatory) at all - and only a short line for the second graph (living room).

A bit of experimentation shows me that this is due to the Jeenode transmissions that update the Jeenode displays! If I turn these off (or even lower the update frequency) then the temperature readings start appearing again.

The high level software in the house monitoring system works on a simple principle

(Click for a larger pic)

All the data collected from the various sensors is sent to a memcached instance running on one (or more) of the servers, and stored together with a timestamp.

A small library makes it easily accessible for all the other software in the system.

In a simple display it looks like this :

As I was feeling rather under the weather on Friday and Saturday I spent some quiet time rewriting parts of the home monitoring software, but before I write up something about the details I;d better describe some of the high level details

(Click for larger image)

On the right hand side are a large number of jeenodes and other nodes with a variety of sensors.