Casting int16_t to uint_8t*

Question

I have a library driven result stored as an int16_t value (and it is a negative, which I can use the absolute value of) and another library function that requires this value a few steps later in the form uin8_t*. How can this be done without using String?

The following code works, but uses dreaded Strings. Is there a way to do this without invoking String or std::string?

 void setup() {
      Serial.begin(9600);
    }

    void loop() {
      delay(5000);
      String initialVal= String(-fetchInt()); 
      Serial.print("Initial value is: ");Serial.println(initialVal);//prints "76"
      uint8_t medianVal[sizeof(initialVal);
      medianVal.getBytes(medianVal, sizeof(initialVal));
      Serial.print("median value is: ");Serial.println(medianVal);//prints "76"
      uint8_t* finalVal = medianVal;
      Serial.print("final value is: ");Serial.println((char*)finalVal);//prints "76"
      }

    int16_t fetchInt(){
      return -76;
    }

So, how can I turn int16_t into uint8_t*?

It has been pointed out in comments below that Serial.println(static_cast<unsigned>(*finalVal)); works, but this solution converts the uint8_t to an unsigned int and the method requires uint8_t*.

I come from Java and the like and it seems crazy that it is so hard to convert an integer to a string.

Answer 1

A pointer of type uint8_t cannot point to an object of type int16_t; you need to copy the value of firstVal, but therefore you'll need a separate object to take on the value.

uint8_t firstValAbs = firstVal >= 0 ? firstVal : -firstVal;
uint8_t* secondVal = &firstValAbs;

Note: uint8_t x = -34 will not give you the absolute value of -34, i.e. it will not result in 34. You'll rather get a two's complement of -34, i.e. 255-34+1 == 222.