Creating temperature graphs
---------------------------

Files:
 - rrd.txt
 - make_rrdr
 - add_measurement_to_rrd
 - draw_graph_from_rrd

1. First one executes the 'make_rrd' script (ONCE!) to initialize the
   database in which measurements are stored.

2. Then, from cron for example one executes every 5 minutes the
   'add_measurement_to_rrd' script. Make sure 'clewarecontrol' is in
   the path.

3. Every time you would like to have the graphs updated (e.g. you want
   to see what was measured), invoke the draw_graph_from_rrd script.

4. After invoking the draw-script, you'll find a 'graph.png'-file in
   the current directory which can be viewed with your favorite
   picture viewer.


These scripts can be easily adapted to measure humidity as well. This
is left to an excercise for the reader.
One hint for the humidity sensor: when the power went off of the
humidity sensor one needs to start it first before the sensor will
start measuring. Use 'clewarecontrol -ag' for that.



For any question related to Cleware devices under Linux, feel free to
contact me at the following e-mail address: folkert@vanheusden.com