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Parallax 433 MHz RF Receiver sighnal strength — Parallax Forums

Parallax 433 MHz RF Receiver sighnal strength

chris joneschris jones Posts: 391
edited 2009-10-19 17:16 in BASIC Stamp
Can anyone help with code that will display the signal strength of a Parallax 433 MHz RF Receiver And Transmiter

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2009-10-19 05:42
    The Parallax 433MHz Receiver provides a received signal strength indicator as RSSI which provides a voltage proportional to the signal strength. The RCTIME statement can be used to implement a slow analog to digital converter that may be what you need. Have a look at Tracey Allen's website (www.emesystems.com). Click on the "app-notes" link at the bottom of the page. On the "app-notes" page, look at the discussion on the RCTIME statement, particularly its use for a battery voltage monitor. That should let you monitor the RSSI output voltage just like a battery level. You'll need to calibrate the set up by using a 1K or 5K pot between +5V and ground and the pot's wiper as your source of voltage to measure. You could use a voltmeter to measure the wiper voltage and use that for your calibration value.

    Post Edited (Mike Green) : 10/19/2009 5:47:24 AM GMT
  • chris joneschris jones Posts: 391
    edited 2009-10-19 11:50
    i have been looking around is this the right link

    http://www.emesystems.com/BS2rct.htm
  • chris joneschris jones Posts: 391
    edited 2009-10-19 16:28
    i have read and i am not sure if i understand how thats goiung to work.

    my overall goal is to display the signal strength on my LCD
    ·
  • Mike GreenMike Green Posts: 23,101
    edited 2009-10-19 16:32
    Displaying the signal strength has two parts:
    1) Getting a number from the analog RSSI signal
    2) Displaying that number or a derivative of it on an LCD

    Either the method shown in the EmeSystems' article or using some kind of external ADC will get you #1. There are plenty of examples already available on how to display something on an LCD. You'll have to figure that part out by yourself. It should be easy given the examples.
  • chris joneschris jones Posts: 391
    edited 2009-10-19 16:35
    Is there an exmpale that yoyu can show me ?
  • Mike GreenMike Green Posts: 23,101
    edited 2009-10-19 17:16
    No. There are no ready-made complete examples. The pieces you'll need do exist, but you'll have to modify them and put them together yourself. Even if there were a ready-made example, it probably wouldn't do exactly what you wanted and you'd have to modify it anyway.

    1) You need to try the method shown on the EmeSystems website or something else like using an ADC. There are plenty of examples of the use of ADCs in Parallax's tutorials like "Basic Analog and Digital" and in several of the Nuts and Volts Columns. All are downloadable from Parallax's website under the "Resources" tab.

    2) You need to become comfortable with the use of an LCD. There are plenty of examples of this on Parallax's website. Check the webstore page for the display that you have. There are always sample programs with links on the webstore page. Also check the Nuts and Volts Columns. They all have sample code.
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