CO2/Air Quality Home Monitoring

Monitor home air quality metrics (CO2, temperature, humidity, etc.) using Aranet4 sensor, Raspberry Pi, Prometheus and Grafana

Requirements

• Raspberry Pi (or bluetooth-capable device)
• Aranet4 Sensor (or any other bluetooth-capable CO2 sensor)
• Prometheus + Grafana instance (e.g. using free Grafana Cloud account)

Quick Start

Accompanying article: Monitoring Indoor Air Quality with Prometheus, Grafana and a CO2 Sensor

RPi

To find IP if it changed:

nmap -sn 192.168.1.0/24
Starting Nmap 7.80 ( https://nmap.org ) at 2023-12-14 14:20 CET
...
Nmap scan report for raspberrypi (192.168....)
Host is up (0.0048s latency).
...
Nmap done: 256 IP addresses (3 hosts up) scanned in 2.51 seconds

To access:

• Update ~/.ssh/config, e.g.:

Host rpi
	Hostname 192.168....
	User pi

• Then use ssh rpi or ssh pi@rpi to connect.
• Also set the IP in ansible/inventory file.

To set up RPi:

• Populate ansible/files/.env
• Run:

cd ansible
ansible-playbook rpi.yaml

The above playbook install Docker, docker-compose and bluetooth-related packages.

Bluetooth

Find Aranet4 MAC:

ssh pi
sudo su -
systemctl start hciuart  # or enable
bluetoothctl
> power on
> agent on
> scan on
[NEW] Device DD:...:1F Aranet4 26D0F
> scan off
> pair DD:...:1F
# enter PIN displayed on Aranet4 device
> trust DD:...:1F
> agent off
> quit

Aranet Agent

Deploy with Ansible:

ansible-playbook aranet.yaml --extra-vars "aranet_device='DD:...:1F=office' aranet_interval=60"

Or deploy manually

wget https://github.com/MartinHeinz/aranet4-exporter-go/releases/download/v1.0.1/aranet4-exporter_1.0.1_linux_armv6.deb
dpkg -i aranet4-exporter_1.0.1_linux_armv6.deb
vim /etc/default/aranet4-exporter

# Set:
# LISTEN=0.0.0.0:9100
# DEVICES="-device DD:...:1F=office"
# INTERVAL=...

systemctl restart aranet4-exporter

curl http://localhost:9100/metrics | grep aranet

# Should show something like:
# aranet4_co2_ppm{room="office"} 995
# ...

Grafana

At this point metrics should be flowing to Prometheus. To visualize them you can use (import) the included Grafana dashboard into your Grafana instance.

Considerations:

• The dashboard assumes Prometheus datasource is named DS_GRAFANACLOUD-PROM, you will need to change that.
• Aranet4 measures absolute humidity, so it needs to be adjusted for altitude. The included dashboard adds 24 due my altitude, you will need to adjust that. Compare local weather station relative humidity with Aranet4 value to find the offset.

Troubleshooting

• Agents can't read data from sensor via Bluetooth:
  • systemctl restart hciuart (might need to do it multiple times)

Resources

• https://superuser.com/questions/1160934/bluetoothctl-connects-and-disconnects-repeatedly