To start out, I have to say that I managed to get the Setup to run. This is definetely far from optimal (or even usable right now but I might have to figure something out) but if I use an Independent Power Pin for each Sensor (I also have to power a Relay so its not easy) it actually works.
So now I am using:
VIN -> Thermocouple 1
5V -> Thermocouple 2
3.3V -> Relay (its actually a 5v relay but it seems to work, the status lights are just a bit dimmer).
The first Time I ran this, everything seemed to work perfectly. No Error Measurements, the relay worked, everything was fine.
In the Meantime, I have found out that its actually a terrible Idea to use the VIN Pin. It seems like the Max31855 which was plugged into it has died because of overvoltage (there is a noticeable swelling on a Chip and the Device has started to smell terribly).
I am unsure why, or if this was the only cause of its death as I started to power the Arduino with the USB over my laptop (which is always 5v right?). The second time I ran it, there were constant error Messages in both thermocouples. I thought, maybe the Arduino doesnt have enough Power and I plugged into my Arduino Power Supply (9V). I am guessing that the VIN Output will Output whatever Voltage it uses to power the Arduino. So the Arduino switched to 9V, which seemed to be a bit too much for the MAX31855.
Can I even use the VIN for Power Output long term? Would it work if I only use a 5v Power Suply?
I have a 5V transformer which I want to actually use to power everything, but the Sensors dont want to read anything unless they are powered directly by the Arduino. Because I just tried it out and the Transformer will actually power the relay, but if I plug the Sensors into it, the Sensor will just read 0 (I just tried one for now since the other one is dead).
Sorry, the first 5v is the VCC from the first max31855, the second 5v is the Arduino Output.
hmmmmmm
I am unsure about your Datasheet. I have thought about the possibility of the Voltage being wrong (see the dead thermocouple lol), but I think that the Datasheet of yours only relates to the Maxim Integrated Max31855, which looks like this:
but mine is the standard china Max31855K (I checked, its the K Type) like this:
and according to the ebay seller (in the article I posted earlier), it takes everything from 3-5V. So I should be fine using either 3.3 or 5V.
Now I thank you for the Feedback regarding the Capacitor, I just ordered some so I can solder/fix this ( I mean I also have to order another Max31855k now.... )
Sorry that my reply took so long and is so broken up, I have continued experimenting and figured out some stuff along the way.