Cast uint8_t-array to readable format

I have this code, which receives a row of byte-values, inserted in an array. How can I show the content "readable" and not like this: R$⸮⸮>⸮⸮⸮

Here's the relevant code:

  // Read data from UART.
  uint8_t myData[8];
  String myDataString = "";
  int length = 0;
  ESP_ERROR_CHECK(uart_get_buffered_data_len(uart_num, (size_t*)&length));
  length = uart_read_bytes(uart_num, myData, length, 100);
  if (length > 0) {
    for (int i=0; i<length; i++) {
      //SerialMon.write(myData[i]);
      myDataString += myData[i]+",";
    }

    SerialMon.println(myDataString); // should be something like "82,36,18,43,129,255,255,255"
  }

I believe the problem is, that a byte value like 82 in ASCII corresponds to the letter 'R' when displaying it as a character. Is there an easy way to convert the values, so that an element like 82 will show up as "82" instead... or even better: as HEX?

You are correct with your assumption that myData[i] gets interpreted as ASCII-code, but you can easily convert it into a HEX-string as follows:

myDataString += String(myData[i], HEX);