OCC Original Code Consulting

MyRIO Audio Analyzer

    The MyRIO Audio Analyzer is an example program for the MyRIO hardware that acquires and filters two channels of audio data.  The features of this program include:

Overview: This project acquires audio data on the MyRIO, applies filters and effects, uses Network Streams to send the
data to the Host, records data on the host, and displays data on the Host.
Requirements: LabVIEW FPGA Module, Network Streams software on the NI myRIO RT target.
1. Make sure the Target IP Address is set correctly on the Audio Analyzer Desktop.vi to point to the MyRIO hardware.
2. Connect a microphone to the audio input jack. Connect headphones or a speaker to the audio output jack.
3. Run the MyRIO Audo Analyzer RT.vi on the myRIO target and the Audio Analyzer Desktop.vi on the Host, in
either order. 
4. Adjust the Filter Selector and Effects controls as desired.  Press the Record button to save data to a file.  Press the Play
button to send the live, filtered or raw data to the MyRIO audio output.

    The MyRIO Audio Analyzer program was based on the MyRIO Voice Recorder application created by National Instruments.  However, numerous changes have been made to optimize it for this application.  Note that the Voice Recorder used FPGA Control Read functions to acquire the data.  This data transfer mechanism requires significant overhead and is not appropriate for moving large amounts of data between platforms.  Thus the MyRIO Audio Analyzer has implemented DMA-based transfer of the audio data.  This allows the program to successfully transfer more channels at a higher sample rate than could be accomplished with the Control Read functions.
    Another difference between this application and the NI example is that the FGPA code for the MyRIO Audio Analyzer has been customized and recompiled.  Much of the MyRIO functionality that is included by NI in most examples has been removed.  This allows for additional functionality to be added to the MyRIO Audio Analyzer at the FPGA level in the future, as more filtering options and other audio analysis tools are added.
    The MyRIO Audio Analyzer project also uses Shared Variables to communicate commands between the host and RT modules.  Compared to the NI example, communication has also been improved with additional logic added around the Network Streams connections to allow the RT and Desktop programs to be launched in any order and connect as necessary.