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This object is provided under license. By downloading this object, you are agreeing to the terms of the MIT License.

Low Cost 2.4GHz Spectrum Analyzer

This object is a 2.4GHz Spectrum Analyzer using a low cost CYWM6935 module, outputting to a VGA monitor. This appliction sweeps from 2.400GHz to 2.527GHz in 1MHz steps, using the RSSI values of channels 0 through 127 to determine power level. Levels are from 0 to 31, although the values aren't calibrated to any standard measurement.

There is code for enabling a peak hold as well as a cursor, although I didn't define an interface for controlling these. It could be connected to buttons, keypad, serial port, etc.

The interface to this module is SPI, as well as misc pins, several of which can likely be omitted if desired. Note that the module uses a 12 pin 2mm connector rather than the standard 0.1". This could probably be used in a custom circuit using the CYWUSB6935 chip as well. The CYWM6935 module has trace antennas on the board.

This program could be expanded on to make use of the communication features as well, although it's probably not one of the best communication devices, since the speed is slow and the range is quite limited. The module is FCC Approved though, so it may be of use to some. Make sure you only transmit in the channels legal for your territory (according to the manual, US FCC regulations allow only from channel 2 to 79).

I borrowed a lot of the code from the Beau Schwabe's Audio Spectrum Analyzer and SPI Demo, as well as some C code floating around for a similar project on the AVR, which doesn't seem to have a home or author.

Version:
  1.0

Type:
  Object

Attributes:


Author:
  DogP

Categories:
  Tool
  Signal Generation & Processing

Downloads:
  983

Last Updated:
  2009-08-03



User Reviews:

  • Hugh commented:
    An excellent object - once I worked out that the numbering of the CYWM6935 is from the back of the PCB (not the front where the pins are) it was just a case of changing the pin numbers in the spin code and away it went... As mentioned in this post (http://forums.parallax.com/showthread.php?131331-Rayman-s-Propeller-PtP-amp-DogP-s-CYWM6935-2.4-GHz-Spectrum-Analyser&p=995801#post995801), a few modifications got it running on Rayman's PTP board. At the same time I slightly altered the way the peak hold function worked. An excellent, very useful object!
    April 29, 2011 8:18 p.m.


  • ETHIK00 commented:
    This is an extremely simple object to use. All one needs to do is get the module, look at the pinout, read the object pinout - change to fit hardware - then hook it up and run. It's ridiculously simple. Afterwards you get a view of the noisy 2.4-5G spectrum. It would be GREAT if someone could expand upon this to be more useful in focusing on one or two samples@frequency and perhaps add some more triggers and/or speed. I like this object for it's simplicity and potential, but it lacks finesse. If someone could come along and use more cogs (I haven't looked for them) and add some front-end it would be a perfect object. Even so, it does what it says and deserves the credit due.
    December 12, 2009 7:27 a.m.




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