help ping and distance measurement

fred1456 · 2007-07-06 10:00

i have bough a new basic stamp 2 and·a ping)) sensor. The ping work but not correctly, it detect object at 15cm (about 6 inches), but not far of this distance.
Technical spécifications tell the ping detect objects 2cm to 3m.

the routine bellow show me numbers between 90(near) and 422, (15cm to infinite)
(sorry my english is poor)

could you tell me why it don't work far than 15cm ?

the routine

' {$STAMP BS2}
' {$PBASIC 2.5}
x VAR Word
Get_Sonar:
LOW 15
PULSOUT 15, 5
PULSIN 15,1, x
DEBUG DEC ? x
PAUSE 200
GOTO get_sonar

Bruce Bates · 2007-07-06 11:53

Fred -

Perhaps you should start with the sample programs, which can be found at the link below, then go on from there, after you understand them:

http://www.parallax.com/detail.asp?product_id=28015

Regards,

Bruce Bates

D Faust · 2007-07-06 21:43

Bruce,
If you look at the example code, the code posted has the same routine for getting sonar.
Fred,
Are you sure tha the wait is long enough to eliminate echoes? ( That is the the main part of your code that is different. )

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D Faust

Chris Savage · 2007-07-06 22:30

Actually, the routine posted has some conversion being done.· The code above is not displaying the data correctly either.

Get_Sonar:
  Ping = IsLow                                  ' make trigger 0-1-0
  PULSOUT Ping, Trigger                         ' activate sensor
  PULSIN  Ping, IsHigh, rawDist                 ' measure echo pulse
  rawDist = rawDist */ Scale                    ' convert to uS
  rawDist = rawDist / 2                         ' remove return trip
  RETURN

    inches = rawDist ** RawToIn                 ' convert to inches
    cm = rawDist ** RawToCm                     ' convert to centimeters
    DEBUG DEC inches, CLREOL, CR, DEC cm, CLREOL

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Chris Savage
Parallax Tech Support

D Faust · 2007-07-07 00:44

Chris, what i meant by it was the same as the example code is that it uses the same code to get the raw distance from the PING (that is correct right?). Yes, I know that there is conversion being done, but I think that Fred was just trying to get a distance reading farther than the 442 (15 cm) that he recieved. (Fred, correct me if I am wrong) So, the conversions aren't necessary. What is wrong with displaying the raw value?

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D Faust

Chris Savage · 2007-07-08 00:50

Actually, I thought for some reason that the formatter would cause an issue with using the ? to display the variable. The formatter (DEC) isn't needed to do that. My apologies. Take care.

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Chris Savage
Parallax Tech Support

fred1456 · 2007-07-08 09:38

in fact, the detector detect anything far than 15cm and that the probl

Chris Savage · 2007-07-08 17:12

Please contact Tech Support by e-mail at support@parallax.com or tomorrow by phone. Take care.

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Chris Savage
Parallax Tech Support

help ping and distance measurement

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