How to monitor the CM4-WRT-A board temperatures and fan speed (RPM) in InfluxDB

The CM4-WRT-A OpenWrt image includes a service called picod, which communicates with the Raspberry Pi Pico collecting periodic measurements from six temperature sensors on the CM4-WRT-A board, as well as the system fan Revolutions Per Minute (RPM). Below is a screenshot showing an example of an InfluxDB dashboard displaying the six temperature sensors and system fan RPM of the CM4-WRT-A board.

As indicated above, the OpenWrt service picod natively supports InfluxDB. The interface can be configured via the picod config file located at /etc/picod.conf on the CM4-WRT-A router.

Below is a screenshot showing the settings needed for picod to publish data to InfluxDB.

The InfluxDB interface is not enabled by default, so the value of the variable enable_influx_db should be set to true in order to enable this feature. You can change the values of influx_org_id and influx_bucket if you like, just make sure to match what you setup in step 2 below.

As for the influx_token, you can provide one or let InfluxDB generate one for you as part of the setup process below (step 3). The CM4-WRT-A GitHub repository https://github.com/MyTechCatalog/cm4-wrt-a includes a script to setup a Docker container running InfluxDB that will display your board temperatures and fan speed.

How to setup InfluxDB for the CM4-WRT-A router board

1.  If you haven't already done so, clone the CM4-WRT-A repository:

   git clone https://github.com/MyTechCatalog/cm4-wrt-a.git

2. Edit the setup script cm4-wrt-a/setup-influxdb.sh to set a username and password used to access InfluxDB, as well as organization ID and bucket name if you like. The lines to edit are highlighted in the screenshot below.

   

3. Run the InfluxDB setup script to start a Docker container:

   cd cm4-wrt-a && ./setup-influxdb.sh

   Output of running InflxDB setup script.

   

4. The InfluxDB data and config folders will be stored in this folder: cm4-wrt-a/influxdb

   Open the file cm4-wrt-a/influxdb/config/influx-configs in a text editor and copy the token value. An example is highlighted in the screenshot below. Paste this value in the /etc/picod.conf file on the CM4-WRT-A router, overwriting the current value of influx_token. Also make sure that the values of influx_bucket and influx_org_id match what you entered in the  setup-influxdb.sh script in step 2 above.

5. Login to your CM4-WRT-A router via SSH. Stop and Start the picod service using the commands below:

   root@gateway2:~# /etc/init.d/picod stop
root@gateway2:~# /etc/init.d/picod start

You can now navigate to InfluxDB at http://localhost:8086/ and login to setup your Dashboard.