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Wireless On/Off transmission — Parallax Forums

Wireless On/Off transmission

TobitzaTobitza Posts: 1
edited 2013-01-17 07:31 in Accessories
Hello everybody.

I am very new here so, excuse my beginners mistakes (if any).

Do you have an idea on how could I transmit wireless just a basic signal (on/off state of a contact) over a short distance (6-10ft or 2-3m)? The cheapest way possible at both ends (emission and reception point). Available power at both ends is DC.

Let's say, when the contact is closed (ON) in point A, I will have an LED ON in point B, but no wires between A and B. When contact is open in point A (OFF), I will have the LED in OFF state in point B. That's all.

Any ideas would be good.

Thanks a lot.

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2013-01-16 13:12
    Something like these Linx modules would work. Parallax does sell some simple transceivers, but these are bare transceivers that have no error checking and would need to be used with some kind of microcontroller. Another option would be IR. The "IR Remote for the BoeBot Robot" tutorial has a simple modulated IR transmitter in the back that uses an IR LED and a 555 timer to produce a modulated 38KHz IR signal. Parallax also sells IR detectors that receive this sort of IR signal. The problem with this scheme is that there are a lot of IR remotes out there that would interfere with the signal. You could add another level of modulation on top, but that would require a microcontroller.

    Unfortunately, you've got two contradictory requirements ... that of having a really cheap solution and that of having a beginner's level of experience, presumably both hardware and software. You could try the bare 433MHz transceivers, but you're likely to have problems with noise / interference. You could also use a pair of xBee transceivers (see this guide). These can be used without a microcontroller once they're configured using a PC utility program, but they're not a really cheap solution.
  • ElectricAyeElectricAye Posts: 4,561
    edited 2013-01-16 14:01
    Mike's advice is always good.
    And you might want to look over this thread a bit: http://forums.parallax.com/showthread.php/142431-I-would-like-suggestions-for-a-cheap-simple-radio-control-device-for-the-Propeller
  • JLockeJLocke Posts: 354
    edited 2013-01-17 06:08
    And before Duane drops in here, let me suggest the Nordic nRF24L01 transceivers. Cheaper than XBee, but will still require the use of a microcontroller.
  • LeonLeon Posts: 7,620
    edited 2013-01-17 07:31
    They are nice, but overkill for simple on/off control.
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