Pulse Echo Sonar Meter

keuwlsoft

Contains ads

About this app

Uses the audio autput to generate sound pulses and then detects the echo on the microphone. The echo signal can be visulised in a map, Fourier transformed or just as the time-series waveform. Great for investigating/demonstrating acoustics principles.

RECORD_AUDIO Permission to use microphone to detect the echo. WRITE_EXTERNAL_STORAGE Permission is so that data can be saved.

Features/Specifications:

• Sampling frequency 44.1 kHz.
• Sampling duration 0.001 s to 5 s.
• Single / Continuous modes.
• Save Data in CSV files.
• Pulse Generation:
• Single/Train/Chirp.
• Square/Sine waveforms.
• Tukey/Hanning Envelopes.
• Pulse frequency 20 Hz to 22.05 kHz.
• Pulse duration up to 1 s.
• MAP – Visualise the echo. Colour or Black and White. Pixel value from RMS or absolute value. New line for each echo trace. Move device whilst pulse-echoing to generate a map.
• Fast Fourier Transform (FFT) of 8192 data points to determine frequency content between echo detect lines.
• Peak frequency detection
• FFT Averaging

For Indication Only. Use Ear Protection if required. Due to the limits of the typical microphone dB range on most devices, distant echo signal are likely to be too weak to detect clearly unless extra amplification or a strong echo is present.

For fun/educational/research use. This is not ultrasound and NOT suitable for any medical imaging. This app can create annoying loud sounds, so use ear protection if required.

Ratings and reviews

For those that don't know how to use this or cannot get it to read anything besides 0. I managed to get a reading finally. Goto the screenshots for the app and goto the one that shows a reading of 5.XXm and change your settings to match it, make sure you get all of them. I thought I had copied them all and it still wasn't working and then I noticed the yellow "Entry Level" setting was still set to 0.50% as soon as I changed it to something lower i started getting a reading! Good luck!

It does not work. The distance is always 0. If it is supposed to work with echo. What distance is observed if the speaker is close to the microphone?, wouldn't it be expected to add a delay to select the echo that is going to be used for the distance measurement? If the application can do it, the (inexistent) "user guide" does not explains how. In which conditions is it expected to work? Inside a room 6 peaks (to each side) would be expected? How about outdoors? Promising but a fake (by the moment) .

App is great for measuring a sound absorbtion of various DIY acoustic materials and for measuring improvements in reverb/echo of a room. Hovever, user interface is almost impossible to understand and there is not einough documentation or help by the author. App uses nonstandard abberviations, whose meaning is not possible to find by google (eg. Div%, RMS ... ) Meaning of various app modes, functions and graphs is very poorly documented. It is not possible to reset the settings to defaults.

What's new

v1.06 Updated to use newer code methods to better target and run reliably on devices in 2024