BOOSTXL-TUSS4440: Trouble Reading Echo Feedback on BOOSTXL-TUSS4440

Frank Gratton

Part Number: BOOSTXL-TUSS4440
Other Parts Discussed in Thread: TUSS4440

Tool/software:

I am using the development kit BOOSTXL-TUSS4440 with the TUSS Generation III EVM GUI application.

When I try to read the feedback signal in rubber, all I get is noise, and I cannot reliably identify the echo peak. In air (with a 40 kHz transducer), I am able to detect distance measurements up to about 3 meters, but beyond that the signal is too noisy.

My goal is to measure the thickness of a rubber layer that has a metal plate on the opposite side.

So far, I have tried different frequencies and transducers (40 kHz, 255 kHz, 400 kHz). I also increased the output voltage to improve the signal-to-noise ratio, but without success.

My board configuration follows the datasheet recommendations. The J1 and J4 connectors were calculated from Cinn and Cflt values provided in the datasheet.

Here are example graphs of what I see:

40khz

400khz

My question is: could this be a configuration issue preventing me from correctly reading the ultrasonic echo, or is it expected behavior with rubber material?

21 hours ago

0 Alicia Rosenberger 12 hours ago

TI__Genius 13950 points

Hi Frank,

Thank you for posting to the Sensors forum!

What would be the maximum thickness of the rubber that you intend to measure? Rubber has high sound attenuation as it tends to absorb ultrasonic waves. As sound travels through rubber, the signal can diminish quickly making it difficult to receive a clear echo back. To help with this, using a low-frequency transducer is recommended.

From what I understand, some people also use gel couplants to help to ensure good sound transmission and eliminate air gaps, though I personally have not worked with gel couplants before.

You could also try adjusting the TUSS4440's logarithmic gain amplifier to help boost the weak signal from the rubber.

Best,

~Alicia