Arduino / C++ simple array split join

array-split-join.ino

/* 
 *  Simple example of string join and split functions for arrays of uint8_t 
 *  values of known length.
 *  
 *  Output: 
 
------------------
array split / join
------------------
SENDING >> 52 225 210 170 219
RECEIVING << 52 225 210 170 219 
----
SENDING >> 56 6 40 252 154
RECEIVING << 56 6 40 252 154 
----
SENDING >> 139 77 7 114 117
RECEIVING << 139 77 7 114 117 
----
 
 */

String join(uint8_t vals[], char sep, int items) {
  String out = "";
  
  for (int i=0; i<items; i++) {
    out = out + String(vals[i]);
    if ((i + 1) < items) {
      out = out + sep;
    }
  }

  return out;
}

void split(String value, char sep, uint8_t vals[], int items) {
  int count = 0;
  char *val = strtok((char *)value.c_str(), &sep);
  
  while (val != NULL && count < items) {
    vals[count++] = (uint8_t)atoi(val);
    val = strtok(NULL, &sep);
  }
}

uint8_t send_array[5];
uint8_t receive_array[5];

void setup() {
  Serial.begin(115200);
  while (! Serial);
  Serial.println(F("------------------"));
  Serial.println(F("array split / join"));
  Serial.println(F("------------------"));
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int i=0; i<5; i++) {
    send_array[i] = random(255);
  }

  String s_rep = join(send_array, ' ', 5);
  Serial.print("SENDING >> ");
  Serial.println(s_rep);

  split(s_rep, ' ', receive_array, 5);
  Serial.print("RECEIVING << ");
  for (int i=0; i<5; i++) {
    Serial.print(receive_array[i]);
    Serial.print(" ");
  }
  Serial.println();

  Serial.println("----");
  delay(5000);
}