Assistance for Ping Sensor

Keep walking

Hello:

I am a beginner in this world of robotics and sensors, and I have the following problem, for wich I would appreciate your opinion and solution:

I've been experimenting with the Ping Sensor connected to the Homework Board, as indicated in the brief instructions of the sensor.
For some reason that I cannot understand, the sensor functions correctly until is 14 cms appart from the wall. For greater distances the sensor shows always 14 cms, wit no variation.

Any suggestions???

Thanks in advance.

Keep walking.

Mike Green

Can't tell anything from just your description except that this might happen if you declare one of the variables involved as a byte instead of a word. Could you post a copy of your program and the actual values seen. Also either post a diagram of your connections or a good description of it.

Keep walking

Mike:

The code for the PING operation that I am using is (same as the instructions):

' {$STAMP BS2}
' {$PBASIC 2.5}
time VAR Word

DO

PULSOUT 15, 5
PULSIN 15, 1, time
DEBUG HOME, "time = ", DEC5 time
time = time ** 2251
DEBUG CR, "Distancia =", DEC4 time, " cm"
PAUSE 100

LOOP

---

The wiring is also as the instructions.

Regards
Keep walking

dprbrts42

I am experiencing the same/similar troubles with my Ping. I have duplicated the code above, as well as other examples, and the maximum measurement that I will get is 180us or 2 inches. I can get readings for anything closer than 2 inches.

Thank you in advance for any assistance.

dprbrts42

dprbrts42

Interesting Note.... If I insert some sort of blocking device between the two "eyes", i.e. folded up piece of paper, I will get accurate readings up to several feet away.

Did I miss something in the instructions?

Mike Green

I would call Parallax technical support tomorrow. There was someone else recently who had a similar experience (maximum reading too close).

quickster47

You might also consider how you have it mounted. I have found that incorrect mounting of the PING))) can give the exact results you are describing.

Carl

Franklin

' {$STAMP BS2}
' {$PBASIC 2.5}

' Conversion constants for room temperature measurements.
CmConstant CON 2260
InConstant CON 890 
cmDistance VAR Word 
inDistance VAR Word 
time VAR Word 
DO 
PULSOUT 15, 5 
PULSIN 15, 1, time 
cmDistance = cmConstant ** time 
inDistance = inConstant ** time 
DEBUG HOME, DEC3 cmDistance, " cm" 
DEBUG CR, DEC3 inDistance, " in" 
PAUSE 100 
LOOP

Looks like you have your math functions reversed.

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- Stephen