Great looking data from the OpenDendrometer prototype over the last 28 hours! Showing the expected negative displacement at night (i.e. tree swelling) and positive displacement during the day (i.e. tree contraction). In contrast to the previous OpenDendrometer breadboard development unit, this prototype is showing dendrometer data with much less noise and larger changes in displacement. I suspect the primary cause of these improvements is due to design changes that increased rigidity between the tire depth gauge and the tree.

It really paid off to start logging the temperature data from the DS3231 RTC module as well. It is interesting to see the response time between air temperature and the dendrometer measurements. 

It was dark outside when I went to collect the data and update the Arduino sketch. A spooky glow from the Arduino and DS3231 power LEDs.

Next step of the plan is to collect data over a seven day period.