Brian, I have to disagree with you as only one data file (ie: ‘airquality2.txt’) has been produced since I installed the latest test version of ‘weatherdisplay.exe’ (dated: 02:04:41 on 2017-08-22) - in my settings, I have entered the sensor ID number and I have placed a check mark in front of ‘Use local data (for 1.0 and 10.0 PM size data)’! :?
If I look at the creation time of both data files:
- airquality2.txt - created/updated at 18:23:17 on 2017-08-22
- airquality.txt - created/updated at 16:38:54 on 2017-08-22
Brian, first, can we agree (you and I) that the data downloaded from the Thingspeak cloud storage (using the sensor ID) will be the default data, meaning that this (the data downloaded from the Thingspeak cloud storage) will be the data (from either channel #2 or channel #2) that will be use by Weather Display to calculate the current air quality index.
As you indicated, from the data downloaded from the Thingspeak cloud storage, the PM2.5 value from channel #1 will have to be compared with the PM2.5 value from channel #2, making sure that neither value is smaller than 0 (zero) or greater than 500. If both PM2.5 values are close to each other, then the PM2.5 value of channel #1 will be used (to calculate the AQI). If there is a discrepancy between the two PM2.5 values, the smallest PM2.5 value should be considered the correct one (to calculate the AQI).
The data download from the local networked PurpleAir unit (when a check mark is placed in front of ‘Use local data (for 1.0 and 10.0 PM size data)’) should be in addition to the data downloaded from the Thingspeak cloud storage.