Consistency of data across Local MQTT / API / Glow MQTT / Bright App
I've been looking at getting glow data (via the API and MQT) into influxb. In order to make sure I understood the data properly, I started to compare data received via API vs. that received by MQTT vs. data shown on the Bright App.
I thought it would be useful to summarise some of the conclusions (apologies if I'm restating parts of other posts):-
- I have found it MUCH easier to do everything in UTC, displaying in local time as required. If not, a very large rabbit hole awaits... All the comments below are based on the data being in UTC
- Read the API docs carefully three times. Then read again. Then read again.
- API data for different aggregation periods (daily, hourly, half-hourly, minute) is only self-consistent if the time stamp relates to the START of the relevant period. [ I think I noticed another post confirming this] ==> GOOD
- Glow MQTT data (electricity consumption today) is consistent with API data:- e.g. I have P1D data for a given day == 17.326kWh vs last Glow MQTT reading for the day == 17.328 kWh ==> GOOD
- I had a look at local MQ data last night - this was identical to Glow MQTT data for my sample ==> GOOD
- The local MQTT timestamps and Glow MQTTs timestamp (for the same data) are not quite the same - for me there is a difference of 8s (glow = local + ~ 8s). Looks like either DCC or Glow are not using original timestamps on the Glow MQTT flow? ==> ODD..
- The Bright App 30min / hour / day data is shown in LOCAL time (BST). The data for half hour / hour data is identical to the API data (after adjusting for timezone offset). Note that the "day" data will NOT be identical as the API summation is from midnight UTC to midnight UTC, whereas the App summation is from 23:00 UTC to 23:00 UTC . ==> GOOD - Expected Behaviour.
- "Current Day" data on the App does NOT agree with Local MQTT / Glow MQTT "Consumption Today. I was expecting App (current Day) to be [MQTT (current day) + MQTT(last reading yesterday) - MQTT (23:00 yesterday)]. Not investigated this properly, but it looks like the App totals start aggregating at around 23:30 UTC, not 23:00 UTC. ==> BAD
Has anyone found anything that conflicts with the above?
Any idea what is happening re: point (8) in particular? I'd be interested to know what is going on re: (7) also [technical interest, really]
One last point: I like the new Local MQTT feed. It removes a few dependencies, makes it a whole lot simpler, plus makes pricing data available via MQTT. I'll probably continue with a mix of local MQTT + API as (i) I want historical data also.