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Parallax 433 MHz Transceiver (27982) compatibility — Parallax Forums

Parallax 433 MHz Transceiver (27982) compatibility

edited 2014-08-23 20:36 in General Discussion
Hello Parallax Forums,

I am participating in a robotics competition where the goal is to navigate an outdoor obstacle course. At the goal is RF beacon consisting of a Parallax 27982 transciever which transmits using a rotating Yagi antenna and broadcasts the antenna's rotational position. The robots are to be able to measure the signal strength over a full rotation to determine the direction to the goal.

The competition information recommends using a second 27982 on board the robot as the receiver. However, the 27982's is a little pricey, so if possible I would like to use a less expensive receiver.

The inexpensive 433 MHz receivers I have found have generally been ASK or OOK modulation, while the page for the 27982 says it uses AM or CPCA modulation. From my research, I am having difficult understanding the difference between these types, other than that ASK modulation uses an non-zero amplitude for the "off" signal, and whether they are compatible with one another.

Are ASK or OOK receivers compatible with the Parallax 27982 transceiver?

Comments

  • SapphireSapphire Posts: 496
    edited 2014-08-23 20:07
    Yes, the 27982 is an ASK/OOK transceiver.

    Here is the link to the datasheet for the chip on the 27982 module:

    https://www.linxtechnologies.com/resources/data-guides/trm-xxx-lt.pdf


    See page 10, Theory of Operation.
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2014-08-23 20:16
    "At the goal is RF beacon consisting of a Parallax 27982 transciever which transmits using a rotating Yagi antenna and broadcasts the antenna's rotational position." - THAT is a really cool idea !! I might have to borrow that.

    As far as the different receivers you will be better off with the same communication modulation. While one may work with the other, they may not be optimal. We used to sell a Transmitter (27980) and Receiver (27981) Pair at Parallax, but that has been replaced with the single Transceiver (27982) unit. If you could find the single receiver (27981) then that would work for your design.

    I'm kinda surprised they are allowing the use of the transceiver. You could be malicious/mischievous/ornery and once you receive the "proper" heading, you could Transmit false information to confuse your opponent. :-)
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-08-23 20:36
    No pricing on the site but it appears Dig-Key has one here. BTW, welcome to the Forums and good luck on your project. If I find any other links I will post them.

    EDIT: This site has the Data sheet and is showing the Digi0Key price as $39.99. It looks like the only other place that may have them is North Star Micro. I tried eBay with no luck.

    Maybe erco can find one!!!
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