ping and ping bounce

Gary DeBerg

Hi All
Along time ago I read some place that the ping sensor is not that stable as the receiver
has to lock on to the ultrasound coming back to have an output and that some times it
may take one to three cycles for it to do this.

I have looked at the forums and can’t find any thing on this.

Gary DeBerg
UNL
Bio. Sys. Eng. Dept.

Mike Green

The PING))) sensor is not designed to be a high resolution device. The receiver does have
to lock on to the returned signal because it's unpredictable and because there could be other
sound in the space. The echo could return over any path with one or more bounces.

Gary DeBerg

Thank-you

Do you know how much the bounce will be at say at 15 cm?

Gary DeBerg

Mike Green

"bounce" is used here the same as "reflect". The PING))) produces a pulse of ultrasonic sound which radiates outward from the transmitter in roughly a wide cone distribution. As this hits various surfaces, it will "bounce" off the surface. Some of this sound energy will return to the receiver and some will "bounce" or reflect in other directions. Some of this energy will eventually return to the receiver via multiple reflections and its path length may have no relationship to the distance to the last point of reflection. The PING))) will report the path length for the first valid echo received.

Gary DeBerg

Sorry the bounce in the PULSIN number is the bounce I have a question about.
If a 40kHz has a wavelength of 8.6 mm than if the ping sensor missed the first
reflected wavelength the jitter in the PULSIN number will = about 8.6 mm right?

Gary

allanlane5

There IS a "silence Period" where the Ping ignores ALL returned echoes. This limits how "close" something can be and still be detected -- I think the docs go into this issue.