EXPERIMENT-1 BLOG

The most important thing that this lab taught me was the difference between a DSP processor and a general processor. Most general purpose microprocessors are present in personal computers. They are often used for computation, text editing, multimedia display, and communication over a network. Other microprocessors are part of embedded systems. These provide digital control over practically any technology, such as appliances, automobiles, cell phones, industrial process control, etc. The DSP processor, on the other hand, is a particular type of microprocessor. DSP stands for digital signal processing. It is basically any signal processing that is done on a digital signal or information signal. A DSP processor is a specialized microprocessor that has an architecture optimized for the operational needs of digital signal processing. DSPs also tend to be two to three times as fast as general-purpose microprocessors. This is because of architectural differences. DSPs tend t...

This experiment was based on getting input of various sensors using ADC and display the output on DSO using DAC. Digital-to-Analog converters (DACs) and Analog-to-Digital converters (ADC) are important building blocks which interface sensors (e.g. temperature, pressure, light, sound, cruising speed of a car) to digital systems such as microcontrollers or PCs. An ADC takes an analog signal and converts it into a binary one, while a DAC converts a binary signal into an analog value.Applications for DACs span a wide range, from consumer audio to precision instrumentation, and everything in between. A DAC produces a set of analog values that corresponds to the digital input codes. Many DAC designs are actually current output devices, instead of voltage output devices.

Here we have written a code on CCS to generate  Sawtooth, Triangular and Sinusoidal waveforms and observe the output on the DSO. Analog-to-Digital Conversion (ADC) and Digital-to-Analog Conversion (DAC) are the processes that allow digital computers to use and output these everyday signals. The DSP board that we have used had a 4 channel DAC and 2 channel ADC. We gave a variable voltage to one channel of the ADC via a potentiometer (the voltage was positive) and then using the digital value we gave it to the DAC and observed the output on the DSO.

Here we have implemented a 4bit LED Binary counter using Flash Programming.Till now we have used the internal volatile memory of the F2833x to store the code for our examples. This approach is fine for projects where we there are frequent changes to parts and components  of the software. However when it comes to stand-alone embedded systems we no longer have the option to download the control code .For stand-alone applications we need to store our control code in the Non-volatile memory in this way the system will do the task immediately after system power up.

This experiment was to perform Linear filtering using OAM (Overlap Add Method) and  OSM (Overlap Save Method). Here we have a long sequence data x[n] whose response has to an impulse function here(h[n]) has to be observed. For this the length of the data sequence must be sufficiently larger than the impulse that is applied to the system.  In OAM we decompose the long input data sequence into smaller segments of lesser length, then we operate linear convolution to get segmented outputs of all the decomposed segments. After that we combine these outputs to obtain the final output. In OSM also we decompose the input data into smaller segments.The answer which we get for the linear convolution of the input data is the same by OAM method and OSM method.  

This experiment was based on developing a program to perform FFT and DFT of a N point signal on CCS.  DFT is one of the most powerful tools in digital signal processing; it enables us to find the spectrum of a finite-duration signal x(n). We observed that as the length of input signal increases frequency spacing and error decreases and resolution increases.  FFT is an algorithm that samples a signal over a period of time and divides it into its frequency components.FFT is a simpler and faster method. This is very useful when the value of N is large.

So we performed this experiment on the PC in ubuntu and on CCS. The aim of this experiment was to find auto/cross correlation and use Karl Pearson formula. We took a 4 point sequence in this experiment .We observed that correlation is a Mathematical tool that compares two signals and tells about the degree of similarity between them. This concept can be used for measuring the similarity of signals especially for “pattern recognition “and for “signal detection".

This experiment was based on the different types of convolution . We had studied about convolution in the last semester in Signals and systems. In convolution we have done linear convolution which is based on linear time invariant system.Circular convolution is defined for finite length functions.We have calculated LC using CC by padding the input sequences with zero. Convolution is quite often used as a method of implementing filters of various types.We have observed the output on Code composer studio(CCS).

So this entire experiment was done on code composer studio (CCS) simulator and we observed the output in the ccs software itself . All the concepts and theory of this practical were taught in our Digital communication subject. The aim of the experiment was to develop a program on BPSK(Binary shift keying) , DPSK ,QPSK and harmonic generation. Phase Shift Keying (PSK) is the digital modulation technique in which the phase of the carrier signal is changed by varying the sine and cosine inputs at a particular time. In BPSK  the sine wave carrier takes two phase reversals such as 0° and 180°. In QPSK This is the phase shift keying technique, in which the sine wave carrier takes four phase reversals such as 0°, 90°, 180°, and 270°. We then observed the waveform for harmonics which showed the fundamental frequency 1st and 2nd harmonic.