How to use "bitmap" in LoRa Serialization library?

Application Development
7

Ah! BIN is being received and printed to HEX. So does that explain when encoding with this json

{"delay": 241, "myFlags": [true, true, true, true, true, false, true, true]}

on TTN to downlink, I am receiving the encoded 3-byte payload “F1 00 FB” that prints the second byte “0” instead of “00”?

data array[i], HEX: F1 0 FB 
data array[i], BIN: 11110001 0 11111011

Using a delay greater than 255 …

{"delay": 600, "myFlags": [true, true, true, true, true, false, true, true]}

of course extends into the second byte:

data array[i], HEX: 58 2 FB 
data array[i], BIN: 1011000 10 11111011

Here are the TTN custom Payload Formats custom_decoder_2.txt (2.8 KB) and custom_encoder_2.txt (2.1 KB) .

On the node, this receive allowed for decoding when receiving downlink on port 2:

//from:  https://github.com/GrumpyOldPizza/ArduinoCore-stm32l0/issues/67
void callback_onReceive() {
  onReceive = false;
  if (LoRaWAN.parsePacket()) {
    uint32_t size;
    uint8_t data[256];
    uint8_t portNum = LoRaWAN.remotePort();
    size = LoRaWAN.read(&data[0], sizeof(data));
    Serial.println(" ");
    Serial.print("portNum = ");
    Serial.print(portNum);
    Serial.print("   size = ");
    Serial.print(size);
    Serial.println(" bytes");
    if (size) {
      Serial.print("   data array[i], HEX: ");
      for (int i = 0; i < size; i++) {
        Serial.print(data[i], HEX);
        Serial.print(" ");
      }
      Serial.println();
    }
    if (size) {
      Serial.print("   data array[i], BIN: ");
      for (int i = 0; i < size; i++) {
        Serial.print(data[i], BIN);
        Serial.print(" ");
      }
      Serial.println();
    }

    //read and decode the bitmap from lora-serialization library
    if (portNum == 2) {
      Serial.println("Port 2 downlink");
      if (size) {
        //see: https://www.thethingsnetwork.org/forum/t/decrypting-messages-for-dummies/4894/20
        int setDelay = data[1] << 8 | data[0];
        Serial.print("   Delay:  ");
        Serial.println(setDelay);
        uint8_t  bitVal = data[2];
        Serial.print("   Bit:  ");
        for (int i = 7; i > -1; i--) {
          Serial.print(bitRead(bitVal, i));
          Serial.print(", ");
        }
        Serial.println(" ");
      }
    }                    //end if portNum = 2
  }                    //end parsePacket = T
}                   //end callback on receive

The following links gave some assistance learning more about bytes and bits:

Thank you very much for your guidance @arjanvanb and your point @mfalkvidd!

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