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Ultrasonic transducer

Posted: Tue Aug 29, 2023 8:18 am
by Fraunhofer_MT
I am thinking about using the Red Pitayas "Stemlab 125-14 Ultimate Kit" as a digital regulator. Therefore he has to drive an ultrasonic transducer with a sinus signal and measure current and voltage of it. In addition the Red Pitaya is used to measure the admittance and phase of the ultrasonic transducer.

I got some questions about the STEMlab 125-14 Ultimate Kit:
1.: Is it possible to use the given specifications at " signal generator" one to one with the programmatic (API) use of the Red Pitaya?
2.: How far is the signal frequency and amplitude (min and max voltage) adjustable when using the Red Pitaya programmatically?
3.: What is the accuracy of impedance and phase measurement at frequencies from 1Mhz to 50MHz?
4.: What is the possible bandwidth of the Red Pitaya? (API)
5.: Which device would you recommend regarding my use case ?

Thank you already

Re: Ultrasonic transducer

Posted: Wed Aug 30, 2023 2:15 pm
by redpitaya
If I understand correctly, you are seeking information on programming Red Pitaya through the SCPI commands ( ... -or-python). Either remotely through Python, MATLAB, or LabVIEW, or using the C programming language on the board itself.

To answer the questions (Unless mentioned otherwise, I am referring to STEMlab 125-14):
1. Yes, the signal generator limitations apply to controlling OUT1 and OUT2 through SCPI (programmatically and API).
2. On STEMlab 125-14, the output frequency can be adjusted between DC and 50 MHz, and the voltage between +-1 V.
3. We do not have any accurate data regarding phase and impedance measurements. The best way to test this is for you to buy a Red Pitaya and try it out yourself. The only documentation on this is located here: ... e-analyzer ... #lcr-meter
4. The bandwidth inside the applications is limited to f_sampling/2 (125 MHz/2). There is an analog anti-aliasing input filter, which filters higher frequencies. So, for example, with a Spectrum Analyzer, you can detect frequencies up to 60 MHz.
5. The device choice depends on the specific application, but to start I would recommend the STEMlab 125-14. If you are not interested in lower frequencies and need more resolution, you can also take a look at SDRlab 122-16.

You can find board descriptions and specifications here: ... #hardware

You will not be able to measure the current directly. Red Pitaya only measures voltage, but you can use a small resistor and measure the voltage on it.

To measure and process all the wanted data at once, some programming will be necessary from your side, because currently no one application can handle all the requirements. You can find the code on our GitHub:
and developers' guide will help you with the programming part: ... l#software

If you need any additional help or have some other questions, please let me know.