Blank Serial Print AdaFruit BTLE
I'd probably do it directly like:

for(int i = 0; i&lt;6;  i++) {
  BTLEserial.print(items[i]);
  BTLEserial.print(',');
}
BTLEserial.println();


But with the string I think it would be something like:

String output = "";

for(int i = 0; i&lt;6;  i++) {
  output += getStringForUI32_T(items[i]);
  output+=",";
}
BTLEserial.println(output[0]);


But as someone else got it working using String on your adafruit thread maybe this is just barking up the wrong tree.