Offhand, I’m not sure if that event is made available; I’d have to search the doc. Realize the SmartApp is running on a SmartThings server somewhere (“in the cloud”)…
I had thought about making the queuing logger use the timestamp of when it sends the data, but the way it works now makes (somewhat) more sense. If you only have 1 event queued, then right now it is sent with the correct time. If you have multiple events queued, then they will all get logged with the timestamp of the first queued event. It’s a trade-off between the number of rows in the database and timestamp accuracy.
For instance, I have an SDR that reads my electric meter so that I can measure my usage. I started logging it a year ago when our Solar PV array went live. I originally started logging every data point I collected; that quickly resulted in a few thousand data points a day. I then switched to only changed values. Even then, I have 100K points for a year of data. I finally decided to keep an every 15-minute value and a daily value. Just the daily value is enough to see the trend over time (at least for me):
https://thingspeak.com/channels/123559/charts/1?bgcolor=%23ffffff&color=%23d62020&dynamic=true&results=600&type=line
I’m still deciding how to do visualizations of my data. As you can see, I’m using ThingSpeak for some data. I’m setting up plots off the Google Spreadsheet, and I’m still playing with Grovestreams and local solutions.