Thread Subject:

How to interface with custom-built A/D board

Matlab is able to do data acquisition with AD board from NI, MCC, etc, but i have a different problem.

We have built an ultra-fast A/D board by using a 200 MS/s ADC and an FPGA. The FPGA writes the data to memory via PCI-express. A C++ software takes care of the streaming of data from PCI-ex to memory and did a preliminary processing which reduces the data rate to about 1MS/sec. Now I wish to write a Matlab GUI that periodically read in the data from the memory location and then do some processing/display in real time (update speed ~100Hz). How can I achieve this?

Thank you,

>Now I wish to write a Matlab GUI that periodically read in the data from the memory >location and then do some processing/display in real time (update speed ~100Hz). >How can I achieve this?

You write a mex-file. A mex-file is a C/C++ dll that can do everything a C program can do. In addition, it has an interface to matlab so that it can be called like any matlab function and pass data in and out of matlab. Once you have written this file, you will have access to your the data in matlab and can write a GUI the usual way.

Note, however, that Matlab is not built for high-speed visualisation. Without using some very fancy tricks (so fancy in fact that you might be better off skipping Matlab entirely), you would probably not achieve a visualisation update higher than 10Hz. On the other hand. our eyes have difficulty seeing things faster than 8Hz, so that is probably not an issue.

Read all about mex-files here: http://www.mathworks.com/support/tech-notes/1600/1605.html