Some people were interested in a little more details about how things are working. Here is a little FAQ abot some things:
How are you counting people in the room?
It is quite simple actually. I am counting people with IR door sensors. Two IR emitters are positioned on the one side of the door, and two IR recievers are positioned on the other side. So when you come into the room or leave you trigger both sensors. And then I simply check which sensor has been triggered first. If sensor one has been triggered before sensor 2 - you came in, if sensor two has been triggered first - you left.
How are you controlling the lights?
I bought a few of those cheap remote controlled power sockets and used them for this. I simply opened up the remote, connected the on/off buttons to the two relays on the main PCB and connected one of those sockets to the light. This is cheap, safe (nothing on the board is actually connected to the high voltage) and removes the need for cables for the light (remote controlled sockets usualy work with RF).
Under what license is the hardware/software part of your project?
For now under no license at all. But I am thinking about releasing it under BSD, MIT or Creative Commons license in the short future. But everything should stay open source.
Can you make one of these for me?
Are you going to sell this commercially?
Proabably - no. For a mass production of these things one would need a large amount of money which I don't have. And I don't think that people are that interested in projects like these.
- << Prev