I'm interested in creating a project that I will call the chair prank. The general idea is to incorporate a pressure sensor to a chair and as soon as someone takes seat the sensor, via Bluetooth conects to the door buzzer and make it sound in order that the person as soon as he sits has to stand up to see who is at the door. Is there a way to send via Bluetooth the information to the buzzer conected to arduino uno without conecting directly the sensor to the arduino. Thanx in advancer
Seems possible to me.
You'll need 2 arduino's and 2 bluetooth boards. You could also use cheaper nrf24l01 or other wireless modules as well though.
Instead of using a pressure sensor it may be possible to detect someone using Capacitive sensing, requiring just a piece of metal and 2 resistors.
With an transistor+ relay you could operate the button.
I'd do my best to hide 'evil' intentions by the way. When the doorbell starts ringing at the moment people sit down, they'll soon know there's a relation between both.
If the bell starts ringing after a random period of sitting and occasionally 10-20 secs just after they left the chair though it will be much harder to detect what's happening.
Simpson thanx for your help and suggestions. I'll try it out and as soon as I finish the project I will post the results.