In the past few weeks, we’ve touched on a few examples of how events within applications are surfaced in activity streams.

But it’s not just applications that can communicate. A developer from Portland, Or. is providing a glimpse of how activity streams can be connected with sensors to keep track of activities in an office buildings.

Mike Leach developed Chatter Bot to show how activity streams can be used to notify people about what is happening in a building.

Last week, he entered Chatter Bot in the Chatter Developer Challenge at the Cloudfoce event. He won the grand prize.

The service connects a light and motion sensor to a microcontroller that has an Ethernet connection. The activity detected by the sensor gets pushed to the cloud through the microcontroller. When someone enters a room, Chatter Bot notifies the activity stream of the movement. Leach writes that it costs about $80 per room to install the system.

According to his web site, Leach used the following components to make Chatter Bot:

* Arduino board with motion and light sensors (C/C++)

* Proxy Service (Java Environment)

* Salesforce Sites HTTP Listener (Visualforce/Apex)

* Facility Management App ( database and web forms)

It’s a simple bit of components. The twist comes with providing an Internet connection to the circuit board:

A diagram by Leach showing how the service connects to Chatter:

Leach used Chatter to monitor the activity in the Hackathon room at the the Cloudforce event.

Chatter Bot is an example of how almost anything can be connected to the Internet. There are any number of examples of how this is evolving. Security is one obvious application. But there are any number of possibilities for how sensors may someday interact with activity streams.