RRDTool + Indigo for graphing sensor data

indigo_graph_obasement.py

import rrdtool

# "Original basement temperature sensor"
temp = indigo.devices[401767099].sensorValue 
# "Original basement humidity"
hum = indigo.devices[1437240536].sensorValue 

# update our round robin database
entry = 'N:{0}:{1}'.format(temp,hum)
rrdtool.update('/usr/local/share/obasement.rrd','N:{0}:{1}'.format(temp,hum))

ret = rrdtool.graph("/Users/alan/Desktop/obasement.png",
    "--start", "-2days", "-w 600",
    'DEF:Humidity=/usr/local/share/obasement.rrd:humidity:AVERAGE',
    'DEF:Temperature=/usr/local/share/obasement.rrd:temperature:AVERAGE',
    'LINE1:Temperature#ff0000:Temperature (°F)',
    'LINE1:Humidity#0000ff:Humidity (%)'
)