Export hex codes from string

[mmahyara-eng]

I want to extract the hex code from a string and then insert the extracted hex codes into an array of bytes.
The length of the string and the number of hex numbers are unknown.
An example of what I want:

String myStr="07 12 b6 53 f2";

to

byte myByte[] = {0x07,0x12,0xb6,0x53,0xf2};

[FernandoGarcia]

Look at: https://cplusplus.com/reference/cstring/strtok/

[mmahyara-eng]

I'm new to arduino, can't get that code by myself

[jfjlaros]

You could use a function like this to extract a number from your string.

uint8_t getHex(char const* str, size_t const index) {
  return strtol(&str[3 * index], NULL, 16);
}

Example:

uint8_t myBytes[5]{};
for (size_t i = 0; i < 5; i++) { 
  myBytes[i] = getHex(myStr.c_str(), i);
}
for (size_t i = 0; i < 5; i++) { 
  Serial.print(myBytes[i], HEX);
  Serial.print(' ');
} 

Result:

7 12 B6 53 F2

[FernandoGarcia]

My suggestion become more complicated than I was thinking because I can't find a simple way to convert the token to byte.

void setup()
{
  Serial.begin(115200);
  String myStr  = "07 12 b6 53 f2";
  char *token;

  token = strtok(myStr.c_str(), " ");

  while (token != NULL)
  {
    Serial.println(token);
    token = strtok(NULL, " ");
  }
}

void loop()
{
}

The output is:

07
12
b6
53
f2

[mmahyara-eng]

Excellent, exactly what I wanted

[mmahyara-eng]

Thanks a lot too