Pulse wave amplitude measurement from Arduino

Thread Starter

Daxesh01

Joined Aug 16, 2018
4
Dear Members,

I am looking for some opinion/suggestions for my project. in my application, I have mounted a PVDF sensor (Piezoelectric sensor) on cylindrical rod and I am rotating the rod every 10° with stepper motor. when I transmit an Ultrasound wave on sensor, it gives me voltage output. I want to record my PVDF sensors peak to peak voltage by rotating it every 10° with Arduino (for completing 1 cycle it has 36 measurements ). my sensors output is Burst wave having an amplitude between 20 to 130 mV with 6 MHz frequency(see attachment). I am planning to use AD8319 Log detector (datasheet in attachment) for amplify, the output of log detector is negative slope (means when high amplitude at input, output has low amplitude and vice versa) and pulse wave (as per my input signal range, log detector output will be in range of 550 mV to 1.07 V [calculated from datasheet]) After having 1 ms delay, the next burst appears and thus so on.
Now how can I measure the log detector Pulse amplitude from Arduino? because every time it varies. my ultimate goal is to record and save sensors voltage data automatically in excel data, for that i am using PLX-DAQ (https://www.parallax.com/downloads/plx-daq).

Do I think in the right direction ? I have very little experience on Programming side so If anybody has a better idea to do this or some changes, Please share with me.
Thank you.
 

Attachments

danadak

Joined Mar 10, 2018
4,057
One suggestion a fast peak detector. Some possibilities -

http://www.analog.com/media/en/reference-design-documentation/design-notes/dn61f.pdf

https://e2e.ti.com/support/amplifiers/f/14/t/167314

Another alternative is to use an external fast A/D , say 100 Mhz type
of speed, collect a sample set and use Arduino to establish what the
peak is in the data set.

Still another approach is to use Equivalent time sampling in A/D
conversion, as used in many scopes. This technique however
suffers from large latency. But permits low speed converters to
generate sample set for high speed signals. Signal has to be
periodic.

Think about posting a question, your signal characteristics, at
analog.com or ti.com and ask for peak detection capability in
the A/D, for recommendations.

Regards, Dana.
 
Last edited:

Thread Starter

Daxesh01

Joined Aug 16, 2018
4
Thanks, Dana for reply. I have already tried with Peak detector circuit (DC489A-A evaluation board from Analog device(using LTC5507)). but it works with the only continuous Sine wave. In my case, I have Burst wave so this circuit doesn't work. That's why I go for Log Detector.
 
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