Projects/fridgemon
From 757Labs
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[edit] FridgeMon
The lab has a True GDM series display fridge. It's an older merchandiser fridge that cleaned up quite nicely.
The lab is currently running on an AMX automation system that controls lighting, some power, and audio/video equipment. It is desired to put the fridge on the AMX system so the lights in the fridge are on the system.
During discussion of doing this, it was said, why not just put an ethernet port on the fridge and track temperatures too. Perhaps we can optimize the temperature so the unit runs less
[edit] Immediate Goals v1
- Control of the two florescent light fixtures in the fridge
- Tracking of temperature inside the fridge
- Simple TCP protocol for reading temperature
- Simple TCP protocol for control of light
[edit] Hardware platform
We briefly looked at the Arduino + Ethernet shield, and some other microcontrollers with ethernet hardware and software layers. This project is to be quick turnaround, use it if you want it leave it if you don't at this point.
So we're cheating.
The hardware platform is likely to be a Linksys WRT54G
We can use one of the two serial ports to connect to an Atmel microcontroller. It will read a Dallas 1820 temperature sensor (Dallas 1 wire) and use one of it's I/O pins to drive a solid state relay to control the lighting.
The serial port on the Linksys is 3.3volt (not RS232 compatible), and hopefully the Arduino is as well.
[edit] Software platform
WRT will be running Linux. This will afford us a simple web server where we can make a custom page showing temperature data. There is an Adobe thing that will plot it real time and updates quickly (pfSense uses this.) Also can use other libraries.
It will also make it easy to write a handler for the TCP data.
[edit] Possible features for v2
- SNMPv2
- Password protection
- Digital POT for temperature scheduling
[edit] Generic protocol ideas
- LON<CR> (lights on)
- LOFF<CR> (lights off)
- T<CR> 32F* (ask for temperature, get 32F*)
