CO₂ monitor
Setup & Example
Motivation
Some time ago an article about a low cost CO₂ monitor
came to our attention. A colleague quickly adopted the python code
to fit in our prometheus setup. Since humans are sensitive to temperature and CO₂ level, we were now able to
optimize HVAC settings in our office (Well, we mainly complained to our facility management).
For numerous reasons I wanted to replace the python code with a static Go binary.
Hardware
- CO₂ meter: Can be found for around 70EUR/USD at amazon.com
& amazon.de. Regardless of minor differences between both devices, both work.
- Some machine which can run the compiled Go binary, has USB and is reachable from your prometheus collector.
A very first version of a raspberry pi is already sufficient.
Software
You need prometheus to collect the metrics.
It might make things easier when you set up an udev
rule e.g.
$ cat /etc/udev/rules.d/99-hidraw-permissions.rules
KERNEL=="hidraw*", SUBSYSTEM=="hidraw", MODE="0664", GROUP="plugdev"
Run & Collect
Help
$ ./co2monitor --help
usage: co2monitor [<flags>] <device> [<listen-address>]
Flags:
--help Show context-sensitive help (also try --help-long and --help-man).
Args:
<device> CO2 Meter device, such as /dev/hidraw2
[<listen-address>] The address to listen on for HTTP requests.
Starting the meter export
$ ./co2monitor /dev/hidraw2
2018/01/18 13:09:31 Serving metrics at ':8080/metrics'
2018/01/18 13:09:31 Device '/dev/hidraw2' opened
Credit
Henryk Plötz
& wooga