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I use an USB-WDE1 receiver from ELV to collect temperature and humidity data from thermometers distributed all around the house. To make use of them, I created a Munin plugin that simply reports the temperature and humidity to munin, which in turn draws nice graphs.

The munin plugin supports up to 8 sensors, allows to configure custom sensor names (i.e. "Kitchen" or "Basement") and global warning and critical settings as well as per-sensor warning/critical settings.


Temperature graph Humidity graph


The source code can be found in the git repository. Getting it is as easy as running

$ git clone


The code repository contains installation instructions in munin/README, but here they are again:

  1. Checkout the munin plugin code:
    $ cd /usr/local/src
    $ git clone git://
    $ cd usb-wde1-tools
  2. A process needs to watch the USB interface and log the last line with temperature data into a log file. You can do that manually with

    $ socat /dev/ttyUSB0,b9600 STDOUT |./munin/ test.log

    If you get errors like

    ELV USB-WDE1 v1.2

    then run the following command:

    $ stty < /dev/ttyUSB0 9600 -brkint -opost -onlcr -echo

    The most easy way is to run the logging process is doing

    $ cd munin && nohup ./ &

    once. It backgrounds the logging process and logs into /tmp/usb-wde1-last. This process needs to be started whenever the machine is rebooted.

    You may run make to install the init script.

  3. Link the munin plugin:

    $ cd /etc/munin/plugins
    $ ln -s /usr/local/src/usb-wde1-tools/munin/usb-wde1_ usb-wde1_temperature
    $ ln -s /usr/local/src/usb-wde1-tools/munin/usb-wde1_ usb-wde1_humidity
  4. Configure the plugins. Edit /etc/munin/plugin-conf.d/munin-node and add the following lines:

    env.logfile /tmp/usb-wde1-last
    env.host_name House
    env.sensors 0 1 7
    env.sensor0 Living room
    env.sensor1 Kitchen
    env.sensor7 Outside
    env.sensor1_warning 30
  5. Try it:

    $ munin-run usb-wde1_temperature autoconf

    - should echo "yes"

    $ munin-run usb-wde1_temperature config

    - should display the plugin configuration with all environment variables set

    $ munin-run usb-wde1_temperature
    $ munin-run usb-wde1_humidity

    - should display the current values from the log file

  6. You are done - enjoy.

File: usb-wde1-tools.htm | last update: 2023-04-06 23:45:02 Valid XHTML Valid CSS