// Set to TEMP_PIT, TEMP_FOOD1, TEMP_FOOD2, TEMP_AMB
setControlProbe(TEMP_PIT);
That's one way to do it. The other way is to change this line in setup
// Analog Pins
// Number in the comment is physical pin on ATMega328
#define PIN_PIT 5 // 28
#define PIN_FOOD1 4 // 27
#define PIN_FOOD2 3 // 26
#define PIN_AMB 2 // 25