In the IT world, monitoring the environmental conditions of your data center is something that’s commonly overlooked. There has never been a cheap and easy solution, and it’s easy for the task to fall pretty far down the ‘needs to be done’ list. After being quoted $13,000 for a system to monitor temperature and humidity in one of our data centers, I decided to revive an old project of mine, and build a better system for under $150.
Originally I had used an Arduino Uno to read temperature and humidity data over a USB serial connection. While this was functional, it only gave me the current conditions. I needed to be able to store (and chart) conditions over time. Eventually I settled on using a DHT22 Temp/Humidity sensor connected to a Raspberry Pi as the brains of the operation. Using this platform, I can plot data over time, provide email alerts, and send the data off to our centralized logging system.
The software stack is pretty simple:
- Raspbian is the operating system.
- Some small python scripts collect the data from the sensor module.
- Graphite to store the data and provide pretty graphs.
- Ansible deploys the software and configuration.
Here’s the final device:
And the charts it creates:
Up Next: How to build the hardware.