I've been working on my own makeshift home automation and monitoring project and just wanted to show you guys the progress.
I have terrible OCD when it comes to my house's alarm system being on when I leave (Insurance refused to pay out a claim once).
The alarm system has LEDs to show whether the system is disarmed (LED off), arming (LED flashing) or armed (LED on). So took an I Arduino, added an LDR to monitor the alarm system LED. I decided to add on some more features: I took apart an extra ET remote control I had, and figured out how to connect the remote control's switches via opto-isolators to the Arduino. This allows me to arm/disarm the alarm and open the garage doors. I also added a relay to "short" the intercom system to open the complex gate.
Then I wanted to check the garage doors' status, so I added those magnetic door sensors to my garage doors. I also wanted to measure my electricity usage, so I stuck an LDR to my prepaid meter's flashing LED. I record the timespan between pulses to a SQL Server Compact Edition database to measure electricity usage.
My Arduino is connected to a small Asus eeebox in a cupboard underneath my staircase. I wrote a small webserver in C# and made a site to monitor it with. I figured out that I can use Prowl to send notifications to my iPhone, so now I have notifications whenever the alarm is unarmed or triggered.
A while ago, I had a GSM-based tracker fitted to my car, so my next step is to get the house to turn on the lights when I get close to home.
Some screenshots of the website:
*The temperature is still a fixed value. I'm working on getting a temperature sensor.
Electricity page - Overview (usage for last 24 hours)
Electricity Usage page
Electricity Consumption page
Next step is adding some lighting control.