3 Generate graphs for temperature and humidity by utilizing Munin.
8 0. Keep a logfile with the most recent single line
9 1. Use the munin plugin to generate munin-compatible data from the log file
14 0. Checkout the munin plugin code:
16 $ git clone git://git.cweiske.de/usb-wde1-tools.git
19 1. A process needs to watch the USB interface and log the last
20 line with temperature data into a log file.
21 You can do that manually with
22 $ socat /dev/ttyUSB0,b9600 STDOUT |./munin/log-single-line.sh test.log
24 The most easy way is to run
25 $ cd munin && nohup ./usb-wde1-log-last.sh &
26 once. It backgrounds the logging process and logs into /tmp/usb-wde1-last.
27 This process needs to be started whenever the machine is rebooted.
29 2. Link the munin plugin:
30 $ cd /etc/munin/plugins
31 $ ln -s /usr/local/src/usb-wde1-tools/munin/usb-wde1_ usb-wde1_temperature
32 $ ln -s /usr/local/src/usb-wde1-tools/munin/usb-wde1_ usb-wde1_humidity
34 3. Configure the plugins
35 Edit /etc/munin/plugin-conf.d/munin-node and add the following lines:
37 env.logfile /tmp/usb-wde1-last
40 env.sensor0 Living room
45 $ munin-run usb-wde1_temperature autoconf
47 $ munin-run usb-wde1_temperature config
48 - should display the plugin configuration with all environment variables
50 $ munin-run usb-wde1_temperature
51 $ munin-run usb-wde1_humidity
52 - should display the current values from the log file
54 5. You are done - enjoy.
58 Debugging & Development
59 -----------------------
60 The dummy data generator is a small php script that generates log lines
61 as they would come from the usb-wde1 usb port:
62 $ ./dummy-data-generator.php |./munin/log-single-line.sh test.log
64 Local (non-installed) plugin setup:
66 $ ln -s usb-wde1_ usb-wde1_temperature
67 $ ln -s usb-wde1_ usb-wde1_humidity
71 Running the munin plugin for development purposes is also relatively easy
72 since you can pass the environment configuration variables
73 from the munin configuration on the command line:
74 $ logfile=test.log sensors="0 1 7" ./munin/usb-wde1_temperature
80 cu: open (/dev/ttyUSB0): Permission denied
81 cu: /dev/ttyUSB0: Line in use
83 Only way that I found to fix this was change ownership of `/dev/ttyUSB0` to uucp::
85 $ chown uucp /dev/ttyUSB0