Ultrasonic Sensor - Broken??

everest

Hi, I've got a brand spanking new Ping)) sensor that I just hooked up to my STAMP2. I'm using super simple code, and I'm having all kinds of problems [noparse]:([/noparse] HEre's the code:

' PingTest.bs2
' {$STAMP BS2}
' {$PBASIC 2.5}
time VAR Word
DO
PULSOUT 8, 5
PULSIN 8, 1, time
DEBUG HOME, "time = ", DEC5 time
PAUSE 100
LOOP

The result is 427 or 428 99% of the time, unless I'm within a few inches of what I want to range on. It will randomly give me correct values from say 3-4 feet, but it's very infrequent. I generally just see 428/428. I have the sensor attached to a long phone cord, about 10 feet long, and the two "eyes" are glued into a project case (hot glue, but around the edges, not blocking the sensor at all.

Any ideas? I have no idea why this isn't working. [noparse]:([/noparse]

-Jeff

everest

Note to self (and everyone else). The Ping)) sensors do not like any hot glue around their transducers. . .I scraped the glue away and everything is working perfectly now. . .weird!

-Jeff

SRLM

It's probably dampens the acoustics, although I didn't realize that the body of the transducer was actively in motion. I wonder how that affects the new Ping mount parallax is going to offer?

Chris Savage

It depends on where the hot glue is…we actually used silicone to seal a PING))) module into an enclosure and it worked perfectly. As for affecting the new mounting bracket, these do not touch the transducers. They’re mounted much like they do on the PING))) mounting bracket, except on the other side.

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Chris Savage
Parallax Engineering

everest

The glue basically coated the entire side of the two sensors, making a large "bead" all the way around each transducer. They didn't stick out above the level of the little "buckets" around the transducers, but for whatever read they totally hosed up the readings. Once I scraped away the bulk of the glue it just started working perfectly, and it's been perfect for a day now.

-Jeff