I am having problems with transmitting large sets of data.
can you help me with the following:
What is the max data size of 'xbee_device_xmit()'Data payload, and if i exceed it will it segment the data into separate zigbee frames?
OK, i found the information in the manual
Be aware that the “manual” might give too small of size. For example some ZigBee move up to 84 bytes I think. For sure you should accept/receive any size up to 255 bytes - don’t make the mistake of saying "max is 72, so I’ll just ask for 72 bytes during recv-from.
This Wiki page gives some suggestions:
http://www.digi.com/wiki/developer/index.php/Determine_MTU
If you are using API mode and have the ZB firmware 2x6x (such as 0x2164 in coordinator and 0x2364 in remotes) then you can send up to 250+ (??) bytes in an APi packet and the XBee will use a ZB fragmentation protocol to move. This only works for AT-transparent mode receives, sends will always be fragmented.
Just a note: in any datagram style reception, one method for detecting overrun is to request one byte more than the expected maximum in the recvfrom request. If the returned length is larger than the expected maximum, the entire frame has overflowed. One won’t know how much it overflowed, but one would protect parsing code that is dependent on the length being a fixed maximum.