Arduino clone with wireless communication


I have been playing around with the JeeNode by JeeLabs recently, a Arduino clone designed for sensor networks. Their primary feature is a a Hope RFM12B radio (No relation to Hackers On Planet Earth) which allows wireless communication. At $20 they are cheaper than Zigbees + Arduino though not as powerful. You can also pick up the radio by itself for under $7.

JeeNode with RFM12B radio unit.

Mehuman and I put together a simple wireless trigger system for the air rockets launch at RobotFest. As a very alpha version it needed to be scrapped mid way through because of communication issues. Turns out handshakes are actually pretty useful.

After that attempt I got a little more into the nitty gritty of the radio and wrote a library. It is simpler than the RF12 library put out by JeeNode creator Jean-Claude Wippler.  For anyone who has used the Serial class for Arduino it will be very familiar. The library should work for either JeeNodes or Arduinos plus a RFM12B communicating via SPI.*

Mehuman is working on a revised version of the code for the rocket trigger for future launches, which should improve communications. More details on that in the future. More details about the radio and jeelabs below…

More details:

  • *Radio operates at 3.3V so need to account for this when hooking up to a 5V Arduino.
  • Operating distance: 200 meters (from datasheet) Haven’t found this to be the case but did manage to send messages from 3rd floor of my house to basement without too many issues.
  • Freq. 915Mhz (North America), 868Mhz or 433Mhz
  • http://news.jeelabs.org/ – Site has discussion, news, and a shop – For US sales see link below
  • http://moderndevice.net/ – US distributor of JeeNodes and RFM12B units, also creator of BB and RBB Arduino clones.
  • RF12 library (by JeeLabs)
  • Ports library –  for accessing the JeeNode pins.
  • My Radio library – Pretty well commented if you want to take it apart.
  • Datasheet – from hoperf.com
  • Programming Guide – gives you the SPI commanded needed to communicate with the radio

5 thoughts on “Arduino clone with wireless communication

  • Jon

    I have read that you can use radios (wi-fi and bluetooth at least) to triangulate the location of a transmitter in 3d space when the location of three or more receivers is know. Any idea if something like that is possible with jee nodes?

    Also, are you finding the batteries are dying while you’re experimenting?

  • John

    I have read that you can use radios (wi-fi and bluetooth at least) to triangulate the location of a transmitter in 3d space when the location of three or more receivers is know. Any idea if something like that is possible with jee nodes?
    +1

  • Kelly Egan Post author

    Hmm to the first question probably. I think it would be a matter of measuring signal strength. There is at least one function on the radio that does a binary read of signal strength for collision protection(make sure not to send packets when there is an incoming signal) so I think if there was a way to measure that more precisely you could triangulate.

    On the battery issue, the only time I have used the radio on batteries is for RobotFest so that probably wasn’t long enough to tell. The JeeNode runs on 3.3volts and the radio can be put in sleep mode (waking up occasionally to transmit data) so batteries should last a long time if its set up right.

  • justin Post author

    There is a function to read RSSI (Read Signal Strength Indicator) so you can do triangulation with it. Triangulation works better with directional antennas though

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