Generating a sine wave
Sinusoidal signals are commonly used in signal processing applications and generating these waveforms provides an interesting project that is the focus of this recipe. A common approach is a direct method that stores the sinusoidal waveform samples in a look-up-table (LUT). This recipe is called dacSinusoid_c5v0.
Getting ready
First, we need to calculate the (12-bit) DAC values that will be stored in the LUT. We'll attempt to generate a 50 Hz sinusoidal signal and use a spreadsheet (for example, Microsoft Excel) to calculate the following values:
|
Smpl. No |
Theta Rads |
floor((sin(theta)+1)*4095/2) |
|---|---|---|
|
0 |
0 |
2047 |
|
1 |
0.31415927 |
2680 |
|
2 |
0.62831853 |
3250 |
|
3 |
0.9424778 |
3703 |
|
4 |
1.25663706 |
3994 |
|
5 |
1.57079633 |
4095 |
|
6 |
1.88495559 ... |
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