dht22 is a small daemon, if you like, that continuously aquires
humidity and temperature readings at configurable intervals and
prints these to stdout and to a file called log.csv in the
current working directory. Each line therein is formatted as
follows:
<YYYY-MM-DD>;<HH:MM:SS>;kk.k;ll.l
With k being a digit of a humidity reading and l corespondingly
being a digit of a temperature reading. A sample line might look
like the following:
2017-12-10;15:17:31;51.1;20.7
Here, a humidity of 50.1% and a temperature of 20.7C was read on 10. decembre 2017 at 15:17:31.
dht22 can be invoked as following:
dht22 [<read delay in ms> [<number of retries> [<retry delay in ms]]]
A sample invocation might look like this:
dht22
Which would trigger default values for read and retry delay and number of retries. Another sample invocation might be:
dht22 60000 10 600
which would try to aquire a reading every minute, with 3 retries and a retry delay of 600ms.
Just the usual
make
should suffice.
The code is heavily inspired by various sources found on the net and tweaked a bit by me.
Sven Schober sv3sch@gmail