Okay WOW thank you for the super quick response. I cannot answer everything right now but I will try to answer everything.
Did you get that original example to prove that the thermos used only one at a time work properly? That is before you added to the code and hardware?
Can you try simply assigned a value like 42.0 to the second thermo, that is leave it in your test code but do not call it:
I understand your Idea, I will try it out this weekend and update you.
Also, can you power your hardware other than through the UNO? It is not meant to be able to supply much power externally; it is best just to plan on not using it. A bit of hanging out will show that power problems pop up perennially in these parts.
True, I noticed flickering etc. with the Display when plugging in different devices. I just ordered a 5v transformer which I will plug into my breadboard. This will then simply power both the Arduino but also the Relay etc.
Do you have a spare pin to use for the second thermocouple's data line? It shouldn't be your problem, but it is an easy experiment.
In Total I have 5 spare pins for the two thermocouples. Considering that I definetely need 2x CS lines (Input Lines into the Arduino, so one from each thermocouple) and a CLK and DO Pin, I have one Pin unused. So I could also use an Individual CLK or DO for the two thermocouples. I have tried switching the Pins around though and it doesnt seem to be an issue.
Those readings will be taking as rapidly as possible - are you convinced you need all that math?
This is the Part where I am not sure. I simply want an averaged reading which uses some of the readings of the last second or two. Without an averaged reading I think the Accuracy is too low to properly control the Temperature.
If you have a better Idea to realise this I would be very glad 