I have 8xMAX31856 and I am trying to use the Adafruit library. Instead of writing all 8 thermocouple channels each time in code (and wasting memory), I want to store the objects in an array and loop through them periodically.

Here is my code:

Adafruit_MAX31856 TCouple1 = Adafruit_MAX31856(2,11,12,13);
Adafruit_MAX31856 TCouple2 = Adafruit_MAX31856(3,11,12,13);
Adafruit_MAX31856 TCouple3 = Adafruit_MAX31856(4,11,12,13);
Adafruit_MAX31856 TCouple4 = Adafruit_MAX31856(5,11,12,13);
Adafruit_MAX31856 TCouple5 = Adafruit_MAX31856(6,11,12,13);
Adafruit_MAX31856 TCouple6 = Adafruit_MAX31856(7,11,12,13);
Adafruit_MAX31856 TCouple7 = Adafruit_MAX31856(8,11,12,13);
Adafruit_MAX31856 TCouple8 = Adafruit_MAX31856(9,11,12,13);

char* thermocouples[] = {TCouple1, TCouple2, TCouple3, TCouple4, TCouple5, TCouple6, TCouple7, TCouple8};

however, I am met with this error on compile:

cannot convert 'Adafruit_MAX31856' to 'char*' in initialization

Why can I not store these variables in an array and call on them later? Is there another way to do this? They work on SPI logic...

1 Answer 1


You CAN store them in an array, but NOT in an array of pointers to characters. That is just the wrong type. Try

Adafruit_MAX31856 thermocouples[] = {TCouple1, ...}

or even ditch the first declarations and use

Adafruit_MAX31856 thermocouples[] = {

I don't have that library installed, but I tried compiling this pattern with the Bounce2 library and it works. That looks like this:

Bounce buttons[] = {
  • Alright! I have tried that and it compiles past it... but how do I loop through this array? I tried for(int i = 0; i<8; i++){thermocouples[i].setThermocoupleType(MAX31856_TCTYPE_T);} and it says it is void
    – NRav
    Sep 23, 2020 at 14:32
  • nevermind... sorted out issue. Thanks for the guidance!
    – NRav
    Sep 23, 2020 at 14:35

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