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// waterfall example
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "liquid.h"
#define OUTPUT_FILENAME "spwaterfallcf_waterfall_example.gnu"
int main()
{
// spectral periodogram options
unsigned int nfft = 1800; // spectral periodogram FFT size
unsigned int time = 1000; // minimum time buffer
unsigned int num_samples = 2e6; // number of samples
// create spectral waterfall object
spwaterfallcf periodogram = spwaterfallcf_create_default(nfft,time);
spwaterfallcf_print(periodogram);
// create stream generator
msourcecf gen = msourcecf_create_default();
// add noise source (wide band)
msourcecf_add_noise(gen, 0.0f, 1.00f, -40);
// add noise source (narrow-band, pulsed)
int id_noise = msourcecf_add_noise(gen, 0.4f, 0.10f, -20);
// add tone
msourcecf_add_tone(gen, -0.4f, 0.0f, 0);
// add fsk modem
msourcecf_add_fsk(gen, -0.35f, 0.03f, -30.0f, 2, 500);
// add chirp signal
msourcecf_add_chirp(gen, 0.17f, 0.10f, -50, 250e3, 0, 0);
// add modulated data
msourcecf_add_modem(gen, -0.1f, 0.15f, -10, LIQUID_MODEM_QPSK, 12, 0.25);
// create buffers
unsigned int buf_len = 64;
float complex buf[buf_len];
// generate signals and push through spwaterfall object
unsigned int total_samples = 0;
int state = 1;
while (total_samples < num_samples) {
// write samples to buffer
msourcecf_write_samples(gen, buf, buf_len);
// push resulting samples through waterfall object
spwaterfallcf_write(periodogram, buf, buf_len);
// accumulated samples
total_samples += buf_len;
// update state for noise source
if (state == 0 && randf() < 1e-3f) {
state = 1;
msourcecf_enable(gen, id_noise);
//printf("turning noise on\n");
} else if (state == 1 && randf() < 3e-3f) {
state = 0;
msourcecf_disable(gen, id_noise);
//printf("turning noise off\n");
}
}
// export output files
spwaterfallcf_set_rate (periodogram,100e6);
spwaterfallcf_set_freq (periodogram,750e6);
spwaterfallcf_set_dims (periodogram,1200, 800);
spwaterfallcf_set_commands(periodogram,"set cbrange [-45:25]; set title 'waterfall'");
spwaterfallcf_export(periodogram,"spwaterfallcf_example");
// destroy objects
msourcecf_destroy(gen);
spwaterfallcf_destroy(periodogram);
printf("done.\n");
return 0;
}
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