Question

How can an integer or decimal variable be converted into a hex string? I can do the opposite (convert hex to int) but I can’t figure out the other way.

This is for Serial.print() hex values in an array.

Answer 1

Take a look at the Arduino String tutorial here. The code below was taken from that example.

// using an int and a base (hexadecimal):
stringOne =  String(45, HEX);   
// prints "2d", which is the hexadecimal version of decimal 45:
Serial.println(stringOne);  

There are plenty of other examples on that page, though I think for floating point numbers you’ll have to roll your own.