Weather station

Figure 1: Hardware in use: Raspberry Pi, Arduino Nano, RXB6 433Mhz receiver, and as many GT-WT-01 temperature/humidity sensors as you like.

Figure 2: Grafana dashboard showing an overview of current temperatures and humidities around the house as well as the status of alerts (e.g., I want to get notified whether my piano is too cold or humid, so I can assure it stays longer tuned).

Figure 3: Temperature and humidity of the fridge within the last 24h (the upper red line defines a threshold of 9° Celsius; so if the fridge gets too warm I get notified in Slack).

Figure 4: Humidity inside rooms and piano.

This is an opinionated (and affordable) setup to measure and log temperature and humidity around the house. Opinionated because I like Go, Prometheus, and Grafana. Affordable because each sensor costs around 10 Euros.

So, in a nutshell, this repo offers you a prometheus exporter for 433 MHz temperature/humidity sensors, where signals are received via an Arduino (with this software flashed to it) connected to a Raspberry Pi.

Happy measuring!

Hardware

You see it all in Figure 1:

Raspberry Pi
Arduino Nano
RF unit for the Arduino (don't try to save a few dollars by buying a cheap one; it has a very tiny range)
GT-WT-01 temperature/humidity sensors (get as many as you like; I bought six on eBay: one for outside, one for every room, one for the fridge, one for inside my piano, etc.)

Update

I realised that the GT-WT-01 sensors seem to be purchasable only in the EU and UK. However, protocols for other sensors can easily be added to the supported protocols of this project, too.

Software

Prometheus
Grafana (you can download the newest Deb packages for the Pi here)
Flash Arduino to recieve signals
Slack (if you want to get notified about alerts)

Download

Get the binary for the Raspberry Pi (ARM) or other platforms here.

Usage

To see options available run $ ./weather-station --help:

usage: weather-station [<flags>] [<ids>...]
  
Flags:
  --help                    Show context-sensitive help (also try --help-long and --help-man).
  --device="/dev/ttyUSB0"   Arduino connected to USB.
  --listen-address=":8080"  The address to listen on for HTTP requests.
  
Args:
  [<ids>]  Sensor IDs that will be exported.

Starting the exporter:

At first, simply start the exporter without any IDs. The logs will show all signals that the exporter is able to decode, but nothing is exported yet.

$ ./weather-station
2018/02/22 13:49:58 Serving metrics at ':8080/metrics'
2018/02/22 13:49:58 Device '/dev/ttyUSB0' opened
2018/02/22 13:49:59 ready
2018/02/22 13:49:59 Wrote command 'RF receive 0' to '/dev/ttyUSB0' (13 bytes)
2018/02/22 13:49:59 ACK
2018/02/16 19:51:05 RF receive 544 4124 2088 9080 0 0 0 0 0102020101020202020101010202020102020202010201010102020102010202020101020103
2018/02/16 19:51:05 {Id:2439 Channel:2 Temperature:18.5 Humidity:70 LowBattery:false}
2018/02/22 13:46:02 RF receive 540 4124 2092 9080 0 0 0 0 0102020102020201020202020202020202020202020201020101020102020102010101010103
2018/02/22 13:46:02 {Id:2320 Channel:1 Temperature:4.5 Humidity:47 LowBattery:false}
...

Write down all the IDs of sensors you'd like export to Prometheus.
Restart the weather station with those IDs (e.g., ./weather-station 2439 2320)

Dashboards

Here is my version of the Grafana dashboard that you see above. Feel free to use it as a starting point for customizing yours (of course, sensor IDs need to be adapted accordingly).

Credits

Idea and code of this CO2 Prometheus exporter has been an inspiration and starting point for this project.
All that hard work of reverse engineering the protocols and finding the correct decodings has been already done by the Pimatic project.