I am sending a string to the Arduino via serial, I made the program that sends the data, so I can change it to anything, but for now it sends a string of hex numbers delimited by ':', so for example 00:AA:FF and I need to get that into an int array onto the Arduino, the main problem is I don't always know how big the array will be, sometimes just 2 indexes, other times 16 indexes.

As I said, I made the program sending the data so I can make the data anything, I just need to get an int array to the Arduino and get it back as an int array via serial

  • 1
    is this a school assignment?
    – jsotola
    Commented Feb 11, 2019 at 21:26
  • Do you know an upper limit on how many there will be?
    – Majenko
    Commented Feb 11, 2019 at 21:54

1 Answer 1


You could store the hex numbers in a int array using strtok() and strtol().

char str[] = "00:AA:FF:7FFF";
int intArray[16]; // Maximum number of hex numbers.

void setup(){


  int counter = 0;
  char * pch = strtok(str, ":");

  while(pch != NULL){
    intArray[counter] = strtol(pch, NULL, 16);
    pch = strtok(NULL, ":");
  Serial.print("Item Count = ");

  for(int i = 0; i < counter; i++){


void loop(){}

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