How can I group IO Feeds ?

Hi Becky, I completed my project but ended up posting my question along with my photos in the 'Class Project' list - my bad. Anyway, here it is again in the correct place this time :-

I would like to convert my existing Arduino project, which is a
'Differential Thermostat', to work as an IoT device. It compares the
temperatures from two DS18B20 probes and switches on the relay & LED
if the temperature is a preset amount greater on channel 1. You can
see typical outputs on the 16 x 4 display ( sorry about the dotty
background ). Obviously I need to add the WiFi element and could use an Adafruit Feather Huzzah as my Arduino, but wonder if there is an ESP series device that I could add to a standard Arduino ? ( I only use the RoMeo BLE as it is quick to prototype with, but too expensive for most 'permanent' versions ). I am also struggling a little with passing two analogue values
to Adafruit IO as 'feeds'. I have found out how to define a group and
assign feeds to it, which looks like the way to go. However, I do not
know how to refer to these feeds programmatically in the Arduino IDE ( something like command->save(group.feedname) perhaps ? ).
Also, I cannot see how to manipulate the feeds on Adafruit IO. This may not be possible, but I wish to derive a 'Delta' value which is Temp1
- Temp2. So if I cannot do that, I will simply need a 3rd feed where
this is already calculated. I have already created a dashboard with 3
'gauges' to display the results. Any advice or pointers would be great !
( I got completely lost in the Adafruit IO API docs btw...)

Picture of How can I group IO Feeds ?
Adafruit IO Feeds.jpg
Adafruit IO Dashboard - Differential.jpg
bekathwia14 days ago

What you're asking is possible, but I think you are operating at one layer of abstraction too high-- to compare values from two feeds, pull from them individually, and locally create the delta value (which you can then store in a third feed if you like). There is a sample with the AIO library for dealing with multiple feeds in one Arduino sketch. For project help beyond the content of these lessons, I recommend posting in the Adafruit forums, where the folks who run AIO can help you directly: https://forums.adafruit.com/viewforum.php?f=56&sid...