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8.33 PROJECT 28—WAVEFORM GENERATOR 237

FIG. 8.111 Generated waveform.

8.33.5 Program Listing
Fig. 8.113 shows the program listing (program: Waveform). The program is MENU based
and consists of a number of functions. The MENU has five options and enables users to
choose the type of waveform required. After the MENU choice, a switch statement is used
to read the required parameters for each waveform. Option 1 generates a fixed voltage at
the DAC port. Calling function GenerateFixed generates the required fixed voltage at the
DAC port. Option 2 generates a sawtooth waveform. The number of steps required in the
waveform, the period of the waveform, and its amplitude are all read from the keyboard. Call-
ing function GenerateSawtooth generates the required sawtooth waveform. Option 3 gener-
ates a triangular waveform with same parameters as the sawtooth waveform. Calling
function GenerateTriangular generates the required triangular waveform. Option 4 gener-
ates a sine wave with the required peak-to-peak amplitude, number of points, and the period.
Calling function GenerateSine generates the required sine waveform. Finally, option 5 gen-
erates any kind of waveforms where the sample time (in ms) and the sample points (in volts)
are entered by the user. Calling function GenerateArbitrary generates the required wave-
form. After a waveform is generated, the program remains at the requested function. Pressing
the Reset button on the development board will restart the program so that a new waveform
can be generated if desired.