I am currently busy with a engineering project that requires object surfaces to be kept at constant temperatures inside a wind tunnel. The inside object will contain heating elements and on the outside a thermocouple would be connected.
My idea so far:
The heating element (connected to a relay) should turn on and off depending on the reading the thermocouple obtains.
I am planning to use a MAX31855 thermocouple to digital converter and then a K-type thermocouple.
I need to control the temperatures of a few surfaces (probably 5 ) and would like to know how many surfaces i would be able to control with one arduino board