tempr.py: send temperature to Graphite

Uses connected USB TEMPer device to do room temperature reading, and optionally sends data to a graphite instance.

Tested using this device, but others may work as long as they identify them selves using a USB ID matching 0c45:7401 Microdia (check using lsusb).

Using

$ ./tempr.py -h
usage: tempr.py [-h] [--no-send] [--fahrenheit] [--host host] [--port port]
                [--metric metric]

Send temperature to graphite using TEMPer device.

optional arguments:
  -h, --help       show this help message and exit
  --no-send        do not send reading to graphite server (default: Do send)
  --fahrenheit     output temperature in fahrenheit (default: Use celsius)
  --host host      address of graphite server (default: localhost)
  --port port      port of graphite server (default: 2003)
  --metric metric  graphite metric name (default: local.temp)

Do reading and send to remote graphite server (note sudo):

$ sudo ./tempr.py --host graphite.local --metric kitchen.temp
Temperature reading: 27.6°C
Sending to Graphite on graphite.local:2003...
Data sent successfully.

Requirements

pyusb (libusb bindings for Python) is required for reading temperatures. Use pip install, or install equivalent system package, eg. apt-get install python-usb on Debian/Ubuntu.

Caveats

Escalated privileges are often required for communicating with the USB device. To easen up this requirement, create /etc/udev/rules.d/99-tempsensor.rules with the following content:

SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="0c45", ATTRS{idProduct}=="7401", MODE="666"

Credits

Magic values stolen from https://github.com/padelt/temper-python

License