C / C ++ Library or Sample Code for DSP Using TI-MSP430

Question

I am working on a small dsp project dealing with audio processing (e.g. Nyquist sampling, oversampling, downsampling, reconstruction), which is embedded in real time using my board. The current board / chip I'm using is the msp430 series from Texas Instruments.

MSP430F5438 Expert Council - (among recommendations) http://focus.ti.com/docs/toolsw/folders/print/msp-exp430f5438.html

First of all, you would recommend buying a copy of matlab or an octave as the main coding tool. I am using CCS (code composer studio) from Texas Instruments, from which I came with my board.

Secondly, there is a DSP library (Open source) for c / C ++, which I can use for my project.

Answer 1

I think Matlab can be useful for getting algorithms "on paper" without worrying about hardware. It is also useful for various DSP functions that you can try (which either come with Matlab or are available as a package / toolkit). However, the function that you get "free" in Matlab must be rewritten if it does not exist in the C / C ++ library.

You will also need to get the code in MSP - I used CCS in the past, as well as IAR Systems , which I was very pleased with.

For your second question, check out the answers to this SO question, which asks the same thing. One link that looks promising is as follows: http://spuc.sourceforge.net/ .

Answer 2

Your board should have code examples. According to the page you linked to above, it comes with MSP430F54xx Code Examples (Rev. O) (zip 525 KB) . Have you tried any of these examples?

Answer 3

In general, using a high-level language for algorithmic development is a great idea. I heard, although I don’t know for sure, that Code Composer Studio has integration with MATLAB to the extent that you can run MATLAB code directly on your target. If

• It's right,
• you have a budget for him and
• you are not trying to squeeze every gram of performance from the chip,

then this is definitely a great feature. Otherwise, Octave is a very good alternative. It is sometimes slower than MATLAB, and does not have some more exotic toolkits, but for prototyping and training it is perfect and FREE.

I recently used Python with NumPy for prototyping, and I am very pleased with that. You might think about this, not MATLAB / Octave, especially if you came from C ++. It’s easy to work with the language, unlike MATLAB, and the NumPy extension libraries (and sometimes SciPy) provide many of the same basic functions. It's also easy to invoke C libraries from Python, providing an easy way to transfer pieces of your high-level files to C iteratively.

As for libraries, I also heard well about SPUC , which is gary comtois . I did not work with the TI chip after a while, but they used to create some building blocks, such as sin , cos , FFT and biquad in various application notes or even as a link library.

Answer 4

The MSP430 is not a specialized DSP processor. However, this does not mean that you cannot process audio with it, but it may not be easy.

I would try to set up timer interruption at the required sound sampling frequency, which reads a sample from the ADC, does something for it and outputs it to the audio DAC.

You only have a 12-bit ADC, so don't expect miracles or CD-quality audio.

 void my12KHzTimer() { writeDAC(readADC() / 2); // DSP loop to reduce volume by 6 dB } 

writeDAC and readADC are supposed to do what they say on tin ...