tree 8e8863a9ca66039faedfa2b3cf28ff6a10bd4466
parent 1d4979c7e3996a4ab80915f320536cc9e78f41e8
author Patrick Williams <patrick@stwcx.xyz> 1604513653 -0600
committer Patrick Williams <patrick@stwcx.xyz> 1604515268 -0600

Threshold: define values to represent un-set threshold

Some existing implementations were using the value 0 to indicate an
unset threshold, but this makes it impossible to have a threshold of 0.
Zero is a reasonable threshold for some sensors, such as a lower-bound
on a temperature sensor.

Specify that 'NaN' should be used to represent thresholds which are not
defined.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I518b4b77a5f7601ea7079980f77c31991f6f9dde