Voice data recording and processing using Analog Discovery

[jfdo]

Hi,

I am wondering whether the scope channel in Analog Discovery can record a voice data from a microphone.? and do signal processing such as averaging, FFT etc?

Suppose, I have a mic and mic-amplifier. Can feed the output from the mic-amplifier straight to scope input? and then see the waveform in the scope mode?

If so, is it then possible to save the voice data for ( say 10 seconds) and then do the processing (averaging and then to perform FFT to extract the frequency components?

If so what is the best way to start?

Also, if created a complex waveform in the AWG (waveform generator), can I use the scope to store the waveform and the do digital signal processing (DSP)?

Thanks any ideas and comments.

 

Best Regards

Fernando

[BogdanVanca]

Hello @jfdo,

To answer on your first question, yes you can. But, either if you are talking about AD1 or AD2, the default scope buffer size is 8kSamples/channel. The WaveForms Device Manager provides alternate FPGA configuration files, with different resource allocation. With no memory allocated to the Digital I/O and reduced memory assigned to the AWG, the scope buffer size can be chosen to be 16kSamples/channel. In telephony, the usable voice frequency band ranges from approximately 300 Hz to 3400 Hz. So your sample rate has to be around 8 kHz.  That means, you can record 1s of audio data. Or 2s if you chose to have 16kSamples/channel. I can recommend to you the OpenScope MZ, please check this link  : https://store.digilentinc.com/openscope-mz-open-source-all-in-one-instrumentation/  , and that is because, OpenScope MZ comes with a maximum buffer size of 32640 samples per channel, giving you another 2s of audio data. You can export your acquired data and save it as a .csv file. After that, you can import it back and do the signal processing. For your third and four question, yes you can. You only need to be sure that your mic output doesn't go higher than the maximum input voltages limits, wich are up to ±25V on each input (50V differential). 

[jfdo]

Hi  Bogdan,

I have the good old AD1 module.

Thank you very much for the very clear answers. I really appreciate. Also thanks for the link to OpenScope MZ. That looks promising with WiFi enable chip on board.

To increase the time for audio recording ( say for 6 seconds), can I use an external buffer (ram or shift register) to buffer the data from the mic-amplifier and then let the scope to sample the data packets of 8k samples (per second)? 

Thanks

Cheers

Fernando

[BogdanVanca]

Hello @jfdo Fernando,

 

Theoretically yes, it should work. But, I personally think that would be extremely difficult. First of all, you cannot control the exact moment on which OpenScope Mz, for example, starts to sample your data. Or I have no idea if you can control the exact moment on which your external buffer starts to feed OpenScope. So, you probably may loose samples or you you will have a lots of zeros. With other words, it would be extremely difficult for you to sync the external buffer with the OpenScope. Also, all the signal processing can be made on 8k or 16k buffers, and trying to glue all your diagrams together it's not a very good idea. It's not very professional.

[jfdo]

Hi Bogdan,

Is it possible to connect  ESP8266 to AD1 for data processing?

Thanks

 

Fernando

[attila]

Hi @jfdo

I think you could use the WiFi module with Analog Discovery and WaveForms application Protocol and Script interface or WF SDK, with UART, SPI, I2C protocols, but you would have to write application or script to control this.

You can record multiple seconds with WF app and AD. You might be interested in the Scope/View/Spectrogram, see the link below.

 

You could also use the SoundCard of your computer with the WaveForms application to capture/record and generate/play signal.

 

[jfdo]

Hi  Attila,

This is a nice suggestion. 

I just installed the new WaveForms software  3.8.2 and then selected the Sound Card in the  Device manager.

I can now see the waveform of my voice in the recording mode of the Scope. 

Is there a way to save the sound file (Acquisition) as a WAV, mp3 or any other sound file format? 

Is it possible to replay and listen to the recorded voice?

If you want to process the data for analysis is it possible to save the voice data as a csv file or text file?

Many thanks.

Cheers.

P.S.

I found the following sound card software in the web.
 https://www.zeitnitz.eu/scope_en  

Has anyone use this? or is there a better software?

 

 

[attila]

Hi @jfdo

At the moment you can export the capture to WAV under View/Logging/Script/Example/Export WAV Mono-Stereo IEEE Float

To play the Scope data as sound open View/Audio 

The capture can be exported as CSV/TXT/TDMS/picture... under File/Export (Ctrl+E) or automated under View/Logging

[jfdo]

Hi  Attila,

This is a nice suggestion. 

I just installed the new WaveForms software  3.8.2 and then selected the Sound Card in the  Device manager.

I can now see the waveform of my voice in the recording mode of the Scope. 

Is there a way to save the sound file (Acquisition) as a WAV, mp3 or any other sound file format? 

Is it possible to replay and listen to the recorded voice?

If you want to process the data for analysis is it possible to save the voice data as a csv file or text file?

Many thanks.

Cheers.

P.S.

I found the following sound card software in the web.
 https://www.zeitnitz.eu/scope_en  

Has anyone use this? or is there a better software?

 

 

[jfdo]

Many Thanks Attila.

It is great.

 

Cheers