/*
// Conversion float to hex *** can not
double voltage = 1.2;
//float Xe = 3.3;

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

  serialFloatPrint(voltage);
}

void loop() {
  /*
  serialFloatPrint(voltage);
  //serialFloatPrint(Xe);
  Serial.println();
  delay(200);
  */
  /*
}

// function to print out floats in HEX XXXXXXXXXXXXXXXX
void serialFloatPrint(float f) {
  byte * b = (byte *) & f;  ///**********
  Serial.print("#"); /////#*******************
  for(int i=0; i<4; i++) {
    byte b1 = (b[i] >> 4) & 0x0f;
    byte b2 = (b[i] & 0x0f);
    char c1 = (b1 < 10) ? ('0' + b1) : 'A' + b1 - 10;
    char c2 = (b2 < 10) ? ('0' + b2) : 'A' + b2 - 10;
    Serial.print(c1);
    Serial.print(c2);
  }
}
*/



///////////////////////////////////////////////////////////////
// Conversion float to hex  ***ok***  4-byte = 0x00000000

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

  float value = 5.0; ///*** 3.14=0x4048F5C3
  byte byteArray[4];

  floatToBytes(value, byteArray);

  Serial.print("Float value: ");
  Serial.println(value);
  Serial.print("Hexadecimal value: 0x");

  for (int i = 3; i >= 0; i--) {
    if (byteArray[i] < 0x10) {
      Serial.print("0");
    }
    Serial.print(byteArray[i], HEX);
  }
  Serial.println();
}

void loop() {
  // Nothing here
}

void floatToBytes(float value, byte* byteArray) {
  union {
    float f;
    byte b[4];
  } floatUnion;

  floatUnion.f = value;

  for (int i = 0; i < 4; i++) {
    byteArray[i] = floatUnion.b[i];
  }
}

////////////////////////////////////////////////////////////////

  //*** https://gregstoll.com/~gregstoll/floattohex/