Overview
The office fridge tends to be overloaded and frosty, causing the door to remain open, very often. If the door is left open for too long, the fridge turns on trying to cool the whole office and wast energy(also the beer does not stay cold). We decided to have an alarm sound when the fridge door has been open for too long. The system uses one environmental mote and a buzzer mote. The buzzer mote listens for messages from the environmental mote and when it gets a message were the temperature is above the threshold it sounds the buzzer.
Hardware
The buzzer is very simple. It just uses a 555 timer to to generate a square waveform that is fed to a small speaker.
Here's is the schematic:
The 2k pot shown in the above schematic is used to change the tone.
Parts
All the parts for the buzzer can be picked up at your local radio shack for under $10. Here is a parts list:
Software
Here is the java project for the fridge application.
Note: This project uses one application for both the sensor mote and the fridge mote. You will need to change the mac address in code to fit your deployment.
#Overview
<<<<b
!{200,}[[Buzzer]]
<><><><>
The office fridge tends to be overloaded and frosty, causing the door to remain open, very often. If the door is left open for too long, the fridge turns on trying to cool the whole office and wast energy(also the beer does not stay cold). We decided to have an alarm sound when the fridge door has been open for too long. The system uses one [environmental mote][[EnvironmentalSensors.Home]] and a buzzer mote. The buzzer mote listens for messages from the environmental mote and when it gets a message were the temperature is above the threshold it sounds the buzzer.
||||
#Hardware
The buzzer is very simple. It just uses a 555 timer to to generate a square waveform that is fed to a small speaker.
Here's is the schematic:
![[BuzzerSchematic]]
The 2k pot shown in the above schematic is used to change the tone.
###Parts
All the parts for the buzzer can be picked up at your local radio shack for under $10. Here is a parts list:
* [555 Timer](http://www.radioshack.com/product/index.jsp?productId=2062595&cp=&sr=1&origkw=555+timer&kw=555+timer&parentPage=search)
* [Speaker](http://www.radioshack.com/product/index.jsp?productId=2062406&cp=2032058.2032230.2032266&parentPage=family)
* [Pot](http://www.radioshack.com/product/index.jsp?productId=2062353&cp=2032058.2032230.2032275&parentPage=family)
* [Resistors](http://www.radioshack.com/product/index.jsp?productId=2062304&cp=2032058.2032230.2032267&parentPage=family)
* [Caps](http://www.radioshack.com/product/index.jsp?productId=2062375&cp=2032058.2032230.2032267&parentPage=family)
#Software
@[Here][[fridge.zip]] is the java project for the fridge application.
**Note:** This project uses one application for both the sensor mote and the fridge mote. You will need to change the mac address in code to fit your deployment.
