MATLAB Central Newsreader - real-time data acquisition from a custom device

real-time data acquisition from a custom device

윤영우 — Wed, 18 Mar 2009 02:14:29 -0400

I try to receive and process sound data frame by frame from a custom
audio input board with USB interface in MATLAB. I have used this board
through windows drivers and C APIs successfully in C world.

At first, I made a data receiving thread with C-MEX to copy frame
buffers and call matlab functions to process and visualize the data.
But, I realized that mex functions like mexCallMATLAB are not thread-
safe functions. I had no idea to proceed.

Next, I noticed that the DAQ toolbox adaptor kit may work. Here, I don?
t want to implement complicated timing codes. Just need places for
Init, Start, Stop function and a thread for calling a MATLAB function
with a sound frame.

Do you have any idea or suggestion?
Other fancy solutions are welcome.

If the use of DAQ toolbox is best, I need simple examples or tutorials
relevant to my problem.

Thanks in advance.

real-time data acquisition from a custom device

Sherryl Radbil — Thu, 19 Mar 2009 12:36:01 -0400

Hi,
If your device adheres to the Windows MME interface
(see http://msdn.microsoft.com/en-us/library/aa909811.aspx)
it can be supported by Data Acquisition Toolbox. There are some limitations you can read about here:
http://www.mathworks.com/access/helpdesk/help/toolbox/daq/f5-54943.html
http://www.mathworks.com/support/solutions/data/1-19SDX.html
The winsound interface constrains the sound card to up to 24 bits per sample,
with the default set to 16. This help page gives more information
http://www.mathworks.com/access/helpdesk/help/toolbox/daq/bitspersample.html

If your device does adhere to Windows MME then you can see examples and documentation here:
http://www.mathworks.com/access/helpdesk/help/toolbox/daq/daq.html
http://www.mathworks.com/products/daq/demos.html

Sherryl