Get MAC Address Xbee Arduino

Question

I want to get the MAC address of xbee, but I'm not succeeding.

I have the following code.

uint8_t myaddress[10];

uint8_t shCmd[] = {'S','H'};
uint8_t slCmd[] = {'S','L'};
AtCommandRequest atRequestSH = AtCommandRequest(shCmd);
AtCommandRequest atRequestSL = AtCommandRequest(slCmd);
AtCommandResponse atResponse = AtCommandResponse();

void getMyAddress(){
  xbee.send(atRequestSH);

  if(xbee.readPacket(5000)){
    if (xbee.getResponse().getApiId() == AT_COMMAND_RESPONSE) {
      xbee.getResponse().getAtCommandResponse(atResponse);
      if (atResponse.isOk()){
        for(int i = 0; i < atResponse.getValueLength(); i++){
          myaddress[i] = atResponse.getValue()[i];
        }
      }
    }
  }
  delay(1000);
  xbee.send(atRequestSL);

  if(xbee.readPacket(5000)){
    if (xbee.getResponse().getApiId() == AT_COMMAND_RESPONSE) {
      xbee.getResponse().getAtCommandResponse(atResponse);
      if (atResponse.isOk()){
        for(int i = 0; i < atResponse.getValueLength(); i++){
          myaddress[i+6] = atResponse.getValue()[i];
        }
      }
    }
  }
}

I hoped that the myaddress array were 10 values, because the Xbee MAC address contains 64 bytes.

But the array contains only 8 values, for example: Original Xbee Address is 0013a200408a31bb Result function getMyAddress is 013a20408a31bb

My function loses two zeros.

I print the MAC address with the following code:

for(int i=0; i < 10; i++)
  Serial.print(myaddress[i], HEX);

Any ideas?

score 2 · Answer 1 · answered Feb 19 '14 at 23:10

The problem is your function does not print a leading zero if the number is less than 10.

With spaces between each byte: 00 13 a2 00 40 8a 31 bb

What you are printing with spaces: 0 13 a2 0 40 8a 31 bb

I don't think there is a simple way to print hex values with a leading zero, but you can change how you print to have a space between each byte:

for(int i=0; i < 10; i++) {
    Serial.print(myaddress[i], HEX);
    Serial.print(" ");
}

score 1 · Accepted Answer · answered Feb 21 '14 at 01:11

The MAC address is 64 bits, which is 8 bytes (64 bits / (8 bits/byte)). ATSH and ATSL both respond with a 4-byte value. So you should define my address as 8 bytes, and copy ATSL to myaddress[i+4].

Note that you can use memcpy() instead of looping through the bytes:

memcpy( &myaddress[i+4], atResponse.getValue(), 4);

I'm not familiar with the Arudino's Serial.print(), but if it doesn't support printing a hex byte with leading zero, you can print the MAC with:

for (int i = 0; i < 8; i++) {
    if (myaddress[i] < 0x10) Serial.print( "0");
    Serial.print( myaddress[i], HEX);
}

Get MAC Address Xbee Arduino

2 Answers2