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24khz from a stamp

Randy StadhamRandy Stadham Posts: 17
edited 2006-01-23 15:02 in BASIC Stamp
Hi,

Is it possable to output 24Khz from a stamp I?
I need to drive a ultrasonic transmiter.
If not does anyone have a circuit·to make this possable?

Cheers,

Randy
·

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-01-23 05:32
    Randy,

    ·· Aren't the ultrasonic transducers run at 40 kHz?· 24 kHz would be FREQOUT pin, duration, 24000


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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2006-01-23 06:02
    Randy -

    Take a look at the FREQOUT command.

    Regards,

    Bruce Bates
  • Randy StadhamRandy Stadham Posts: 17
    edited 2006-01-23 10:33
    Bruce and Chris,

    There is no freqout for a BS 1 as far as I know

    Yes most ultrasonic tranducers work at 40 kHz but this one wants 24kHz to drive the MAX489.
    See site:
    http://frontrangerobotics.org/UltraSonic/

    Cheers,

    Randy
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2006-01-23 11:52
    Randy-

    Please take a look at the attached PDF, specifically to Applications Note 12, which shows an entire Sonar Ranging Project, using a BS-1 and a Polaroid Ultrasonic Transducer. These are the original Parallax BS-1 Applications Notes, which for my money are still quite valid today as examples, although they are now a discontinued document. Some of us refuse to delete anything that Parallax once published :-)

    You'll just have to adjust for the differing transmission frequency, but the basic theory should be fine. My apologies for not noticing originally that you were using a Stamp BS-1.

    Regards,

    Bruce Bates
    pdf
    pdf
    BASIC Stamp 1 App Notes v1.9.pdf
    516K
  • Randy StadhamRandy Stadham Posts: 17
    edited 2006-01-23 14:32
    Hi Bruce,

    Thanks for the note. Never hurts to look at what was done in the past. I too never throw anthing away you never know when you might need it.

    I built this circuit a few months ago but never got it to work quite well. I do not have an o'scope which in this canse is almost a requirement. I never got the thing fine tuned enough even though I have a kHz measurement on my multi meter. But That never seemed to help. So I gave up and went and found another circuit.
    I know I should buy a ping but I live too far from you guys. So I started to make one for myself. I am still working on it.

    Thanks for the help.

    Randy
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-01-23 15:02
    Sorry Randy, didn't notice the I in your message.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
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