homeclimate V1.5

homeclimate V1.5

Since I have a NAS/server running a TIG stack (Telegraf/InfluxDB/Grafana) for monitoring, it is straight forward to log all sensor data to this machine instead of the Raspberry Pi. The server is consuming a low amount of power, it is running 24/7 to offer its services around the clock and can deal with a little bit of additionally data no problem. This also has the benefit to deliver long time series much quicker than the small Raspberry Pi. Plotting half a year of 30s intervall data in Grafana on a Raspberry Pi 3B+ is a nice stress test – it maxes out the CPU for several minutes and puts a lot of stress on the SD-Card.

Apropos SD cards: A reminder to a note in the first part of this build
Never, and I mean NEVER, run influxdb or any other database for more than a short test on an SD card or USB stick. The flash cells are simply not meant for that amount of load and will wear out in no time. I wrote to death two USB sticks in 5 weeks and 3 months just to see how long they would hold up. The data rate from just these few sensors and the Telegraf monitoring is still very low, so even an old 2.5″ hard disk can handle the throughput but is much, much more resilient to the constant load. Annoyed by the constant humming of the hard drive I then switched to an old 128GB SSD. Theoretically, the flash cells in the SSD will also wear out someday but I don’t care if it breaks in ten or twenty years.