Nicholas Skinner

Freelance website and web application developer

Active RFID with the Wavetrend L-RX300 and Synapse RF Engine

Synapse with Wavetrend L-RX300 (small)As part of a work project / possible home automation project requiring presence detection I recently purchased some Wavetrend RFID readers, and tags.

Wavetrend has various hardware available including tags suitable for mounting on metal, plastic, personnel, and keyfobs with buttons. Tags also support RSSI such that it is possible to determine approximately how close a tag is to a reader.

On the hardware interface side the Wavetrend RX300 can simply be plugged into the Synapse SN171 Proto Board via a male-male null modem serial adapter.

On the software side the serial data from the RX300 could just be transparently forwarded to a server for processing, however if you have only a small number of tags, and are looking to trigger events on other nodes without depending on an external server processing the data in the middle the better option is to parse the tag data on the Synapse Engine itself.

See below for sample code to parse data from a Wavetrend RX300 reader and send logEvent RPCs to Portal (event log code can be replaced by your own code to e.g. trigger events depending on the tag ID or RSSI). Python code should also be easily adaptable for use on non Synapse hardware.

[Download: Wavetrend L-RX300 Parser]

Related Project: Building An Active RFID People / Asset Tracking System With Mesh Networking

Update 2011-05-20: Suppliers of WaveTrend hardware include:

6 Responses to “Active RFID with the Wavetrend L-RX300 and Synapse RF Engine”

  1. JK Says:

    Very interesting! I’m thinking about picking up an L-RX300 and some active tags…. how were you able to deconstruct the data coming from the RX300? Was there documentation on the data structure?

    Thanks for this and the associated articles.

  2. admin Says:

    Wavetrend have a document titled “INTERFACE SPECIFICATION FOR THE L-RX300″ “EAB-00800-03-TS” which has all the necessary information for decoding the protocol however it is marked confidential so you would probably need to talk to your distributor for a copy. I also came across some VB code for decoding tags at http://www.controllingtheinter.net/forums/viewtopic.php?f=121&t=1085

  3. JK Says:

    Thank you sir. You have been most helpful!

  4. Abhay Ghatpande Says:

    Hi Nicholas,

    Did the RX300 need to be powered with a separate power-supply? Now it has been replaced with the RX50, by the way.

    Abhay

  5. admin Says:

    @Abhay

    The L-RX300 I have is powered only from the serial port without any facility for powering it externally. Thank you for the information on the RX50.

  6. Abhay Ghatpande Says:

    That’s great that the RX300 can be powered over the RS232. The RX50 needs a separate power supply, kind of defeating the purpose of the Protoboard. I’m trying to confirm with them if the RX201/202 will work in place of the RX300.

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