The PDFs I've pulled up on this sensor indicate it will not tell you absolute
distance.  Is there a way you are getting around this?

-Adam

Gordon Varney wrote:
>
> If you want something different, I don't know your cost restrictions, but
> for $25.00 each and $18.00 in small qty. Siemens offers a 2.4 GHz Doppler
> radar sensor, with antenna built in. (Part number KMY 24) A complete sensor
> that will determine distance and direction by monitoring 2 sensor outputs
> with your A/D microcontroller. Up to 15 feet possible,and very small in
> size. (1.125"x1.5"x.375" approx.) I use them there are great. The Marshal
> distributor in Kansas City MO. has stock.
>
> Gordon Varney
>
> ----- Original Message -----
> From: Dwornik, Sebastian <SDwornik@CRSROBOTICS.COM>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Wednesday, August 25, 1999 1:08 PM
> Subject: Signal filtering through code
>
> > My current robotics project requires me to design and build an accurate
> > and stable IR proximity detection sensor system. It should give feedback
> > of objects up to 5 feet. My chosen tools are the PIC16F84, the
> > LTC1298 12-bit ADC, and the VTR24F1 optosensor from EG&G.
> > The sensor simply contains an IR LED and a photodarlington in a single
> > package.
> >
> > My current solution involves simple noise filtering through code. The
> > opto proximity method is through the use of intensity or signal
> > strength,
> > reflected off an object.
> >
> > Algorithm:
> >         Pulse HIGH!     ; LED ON.
> >         Read ADC        ; Result A = Signal + Noise
> >
> >         Pulse LOW!      ; LED OFF.
> >         Read ADC        ; Result B = Noise
> >
> >         SUB A-B ; Result C = (Signal+Noise) - (Noise)
> >
> >         C = pure signal strength.
> >
> > This has proven to work well for distances up to 8 inches using an 8-bit
> > ADC. This is the first time I'm trying to extend the range, with a more
> > sensitive sensor and a 12-bit ADC.
> >
> > Is there a better algorithm of filtering which would provide greater
> > results? A better sensor, or maybe a better method to the entire
> > project. I have played with Sharps' GP2D02 module as well; and have
> > gotten rather unsatisfactory results. If the current method cannot be
> > improved upon, then my next step is to try one of those 40 khz
> > Sharp IR modules. They won't give me proximity ranging, but
> > maybe reliable object detection; and atleast that's a start.
> >
> >
> > Sebastian