Software to turn the RTL2832U into a SDR receiver
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rtl-sdr/src/rtl_power.c

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/*
* rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
* Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
* Copyright (C) 2012 by Hoernchen <la@tfc-server.de>
* Copyright (C) 2012 by Kyle Keen <keenerd@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* rtl_power: general purpose FFT integrator
* -f low_freq:high_freq:max_bin_size
* -i seconds
* outputs CSV
* time, low, high, step, db, db, db ...
* db optional? raw output might be better for noise correction
* todo:
* threading
* randomized hopping
* noise correction
* continuous IIR
* general astronomy usefulness
* multiple dongles
* multiple FFT workers
* check edge cropping for off-by-one and rounding errors
* 1.8MS/s for hiding xtal harmonics
*/
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#ifndef _WIN32
#include <unistd.h>
#else
#include <windows.h>
#include <fcntl.h>
#include <io.h>
#include "getopt/getopt.h"
#define usleep(x) Sleep(x/1000)
#if defined(_MSC_VER) && (_MSC_VER < 1800)
#define round(x) (x > 0.0 ? floor(x + 0.5): ceil(x - 0.5))
#endif
#define _USE_MATH_DEFINES
#endif
#include <math.h>
#include <pthread.h>
#include <libusb.h>
#include "rtl-sdr.h"
#include "convenience/convenience.h"
#define MAX(x, y) (((x) > (y)) ? (x) : (y))
#define DEFAULT_BUF_LENGTH (1 * 16384)
#define AUTO_GAIN -100
#define BUFFER_DUMP (1<<12)
#define MAXIMUM_RATE 2800000
#define MINIMUM_RATE 1000000
static volatile int do_exit = 0;
static rtlsdr_dev_t *dev = NULL;
FILE *file;
int16_t* Sinewave;
double* power_table;
int N_WAVE, LOG2_N_WAVE;
int next_power;
int16_t *fft_buf;
int *window_coefs;
struct tuning_state
/* one per tuning range */
{
int freq;
int rate;
int bin_e;
long *avg; /* length == 2^bin_e */
int samples;
int downsample;
int downsample_passes; /* for the recursive filter */
double crop;
//pthread_rwlock_t avg_lock;
//pthread_mutex_t avg_mutex;
/* having the iq buffer here is wasteful, but will avoid contention */
uint8_t *buf8;
int buf_len;
//int *comp_fir;
//pthread_rwlock_t buf_lock;
//pthread_mutex_t buf_mutex;
};
/* 3000 is enough for 3GHz b/w worst case */
#define MAX_TUNES 3000
struct tuning_state tunes[MAX_TUNES];
int tune_count = 0;
int boxcar = 1;
int comp_fir_size = 0;
int peak_hold = 0;
void usage(void)
{
fprintf(stderr,
"rtl_power, a simple FFT logger for RTL2832 based DVB-T receivers\n\n"
"Use:\trtl_power -f freq_range [-options] [filename]\n"
"\t-f lower:upper:bin_size [Hz]\n"
"\t (bin size is a maximum, smaller more convenient bins\n"
"\t will be used. valid range 1Hz - 2.8MHz)\n"
"\t[-i integration_interval (default: 10 seconds)]\n"
"\t (buggy if a full sweep takes longer than the interval)\n"
"\t[-1 enables single-shot mode (default: off)]\n"
"\t[-e exit_timer (default: off/0)]\n"
//"\t[-s avg/iir smoothing (default: avg)]\n"
//"\t[-t threads (default: 1)]\n"
"\t[-d device_index (default: 0)]\n"
"\t[-g tuner_gain (default: automatic)]\n"
"\t[-p ppm_error (default: 0)]\n"
"\t[-T enable bias-T on GPIO PIN 0 (works for rtl-sdr.com v3 dongles)]\n"
"\tfilename (a '-' dumps samples to stdout)\n"
"\t (omitting the filename also uses stdout)\n"
"\n"
"Experimental options:\n"
"\t[-w window (default: rectangle)]\n"
"\t (hamming, blackman, blackman-harris, hann-poisson, bartlett, youssef)\n"
// kaiser
"\t[-c crop_percent (default: 0%%, recommended: 20%%-50%%)]\n"
"\t (discards data at the edges, 100%% discards everything)\n"
"\t (has no effect for bins larger than 1MHz)\n"
"\t[-F fir_size (default: disabled)]\n"
"\t (enables low-leakage downsample filter,\n"
"\t fir_size can be 0 or 9. 0 has bad roll off,\n"
"\t try with '-c 50%%')\n"
"\t[-P enables peak hold (default: off)]\n"
"\t[-D enable direct sampling (default: off)]\n"
"\t[-O enable offset tuning (default: off)]\n"
"\n"
"CSV FFT output columns:\n"
"\tdate, time, Hz low, Hz high, Hz step, samples, dbm, dbm, ...\n\n"
"Examples:\n"
"\trtl_power -f 88M:108M:125k fm_stations.csv\n"
"\t (creates 160 bins across the FM band,\n"
"\t individual stations should be visible)\n"
"\trtl_power -f 100M:1G:1M -i 5m -1 survey.csv\n"
"\t (a five minute low res scan of nearly everything)\n"
"\trtl_power -f ... -i 15m -1 log.csv\n"
"\t (integrate for 15 minutes and exit afterwards)\n"
"\trtl_power -f ... -e 1h | gzip > log.csv.gz\n"
"\t (collect data for one hour and compress it on the fly)\n\n"
"Convert CSV to a waterfall graphic with:\n"
"\t http://kmkeen.com/tmp/heatmap.py.txt \n");
exit(1);
}
void multi_bail(void)
{
if (do_exit == 1)
{
fprintf(stderr, "Signal caught, finishing scan pass.\n");
}
if (do_exit >= 2)
{
fprintf(stderr, "Signal caught, aborting immediately.\n");
}
}
#ifdef _WIN32
BOOL WINAPI
sighandler(int signum)
{
if (CTRL_C_EVENT == signum) {
do_exit++;
multi_bail();
return TRUE;
}
return FALSE;
}
#else
static void sighandler(int signum)
{
do_exit++;
multi_bail();
}
#endif
/* more cond dumbness */
#define safe_cond_signal(n, m) pthread_mutex_lock(m); pthread_cond_signal(n); pthread_mutex_unlock(m)
#define safe_cond_wait(n, m) pthread_mutex_lock(m); pthread_cond_wait(n, m); pthread_mutex_unlock(m)
/* {length, coef, coef, coef} and scaled by 2^15
for now, only length 9, optimal way to get +85% bandwidth */
#define CIC_TABLE_MAX 10
int cic_9_tables[][10] = {
{0,},
{9, -156, -97, 2798, -15489, 61019, -15489, 2798, -97, -156},
{9, -128, -568, 5593, -24125, 74126, -24125, 5593, -568, -128},
{9, -129, -639, 6187, -26281, 77511, -26281, 6187, -639, -129},
{9, -122, -612, 6082, -26353, 77818, -26353, 6082, -612, -122},
{9, -120, -602, 6015, -26269, 77757, -26269, 6015, -602, -120},
{9, -120, -582, 5951, -26128, 77542, -26128, 5951, -582, -120},
{9, -119, -580, 5931, -26094, 77505, -26094, 5931, -580, -119},
{9, -119, -578, 5921, -26077, 77484, -26077, 5921, -578, -119},
{9, -119, -577, 5917, -26067, 77473, -26067, 5917, -577, -119},
{9, -199, -362, 5303, -25505, 77489, -25505, 5303, -362, -199},
};
#if defined(_MSC_VER) && (_MSC_VER < 1800)
double log2(double n)
{
return log(n) / log(2.0);
}
#endif
/* FFT based on fix_fft.c by Roberts, Slaney and Bouras
http://www.jjj.de/fft/fftpage.html
16 bit ints for everything
-32768..+32768 maps to -1.0..+1.0
*/
void sine_table(int size)
{
int i;
double d;
LOG2_N_WAVE = size;
N_WAVE = 1 << LOG2_N_WAVE;
Sinewave = malloc(sizeof(int16_t) * N_WAVE*3/4);
power_table = malloc(sizeof(double) * N_WAVE);
for (i=0; i<N_WAVE*3/4; i++)
{
d = (double)i * 2.0 * M_PI / N_WAVE;
Sinewave[i] = (int)round(32767*sin(d));
//printf("%i\n", Sinewave[i]);
}
}
static inline int16_t FIX_MPY(int16_t a, int16_t b)
/* fixed point multiply and scale */
{
int c = ((int)a * (int)b) >> 14;
b = c & 0x01;
return (c >> 1) + b;
}
int fix_fft(int16_t iq[], int m)
/* interleaved iq[], 0 <= n < 2**m, changes in place */
{
int mr, nn, i, j, l, k, istep, n, shift;
int16_t qr, qi, tr, ti, wr, wi;
n = 1 << m;
if (n > N_WAVE)
{return -1;}
mr = 0;
nn = n - 1;
/* decimation in time - re-order data */
for (m=1; m<=nn; ++m) {
l = n;
do
{l >>= 1;}
while (mr+l > nn);
mr = (mr & (l-1)) + l;
if (mr <= m)
{continue;}
// real = 2*m, imag = 2*m+1
tr = iq[2*m];
iq[2*m] = iq[2*mr];
iq[2*mr] = tr;
ti = iq[2*m+1];
iq[2*m+1] = iq[2*mr+1];
iq[2*mr+1] = ti;
}
l = 1;
k = LOG2_N_WAVE-1;
while (l < n) {
shift = 1;
istep = l << 1;
for (m=0; m<l; ++m) {
j = m << k;
wr = Sinewave[j+N_WAVE/4];
wi = -Sinewave[j];
if (shift) {
wr >>= 1; wi >>= 1;}
for (i=m; i<n; i+=istep) {
j = i + l;
tr = FIX_MPY(wr,iq[2*j]) - FIX_MPY(wi,iq[2*j+1]);
ti = FIX_MPY(wr,iq[2*j+1]) + FIX_MPY(wi,iq[2*j]);
qr = iq[2*i];
qi = iq[2*i+1];
if (shift) {
qr >>= 1; qi >>= 1;}
iq[2*j] = qr - tr;
iq[2*j+1] = qi - ti;
iq[2*i] = qr + tr;
iq[2*i+1] = qi + ti;
}
}
--k;
l = istep;
}
return 0;
}
double rectangle(int i, int length)
{
return 1.0;
}
double hamming(int i, int length)
{
double a, b, w, N1;
a = 25.0/46.0;
b = 21.0/46.0;
N1 = (double)(length-1);
w = a - b*cos(2*i*M_PI/N1);
return w;
}
double blackman(int i, int length)
{
double a0, a1, a2, w, N1;
a0 = 7938.0/18608.0;
a1 = 9240.0/18608.0;
a2 = 1430.0/18608.0;
N1 = (double)(length-1);
w = a0 - a1*cos(2*i*M_PI/N1) + a2*cos(4*i*M_PI/N1);
return w;
}
double blackman_harris(int i, int length)
{
double a0, a1, a2, a3, w, N1;
a0 = 0.35875;
a1 = 0.48829;
a2 = 0.14128;
a3 = 0.01168;
N1 = (double)(length-1);
w = a0 - a1*cos(2*i*M_PI/N1) + a2*cos(4*i*M_PI/N1) - a3*cos(6*i*M_PI/N1);
return w;
}
double hann_poisson(int i, int length)
{
double a, N1, w;
a = 2.0;
N1 = (double)(length-1);
w = 0.5 * (1 - cos(2*M_PI*i/N1)) * \
pow(M_E, (-a*(double)abs((int)(N1-1-2*i)))/N1);
return w;
}
double youssef(int i, int length)
/* really a blackman-harris-poisson window, but that is a mouthful */
{
double a, a0, a1, a2, a3, w, N1;
a0 = 0.35875;
a1 = 0.48829;
a2 = 0.14128;
a3 = 0.01168;
N1 = (double)(length-1);
w = a0 - a1*cos(2*i*M_PI/N1) + a2*cos(4*i*M_PI/N1) - a3*cos(6*i*M_PI/N1);
a = 0.0025;
w *= pow(M_E, (-a*(double)abs((int)(N1-1-2*i)))/N1);
return w;
}
double kaiser(int i, int length)
// todo, become more smart
{
return 1.0;
}
double bartlett(int i, int length)
{
double N1, L, w;
L = (double)length;
N1 = L - 1;
w = (i - N1/2) / (L/2);
if (w < 0) {
w = -w;}
w = 1 - w;
return w;
}
void rms_power(struct tuning_state *ts)
/* for bins between 1MHz and 2MHz */
{
int i, s;
uint8_t *buf = ts->buf8;
int buf_len = ts->buf_len;
long p, t;
double dc, err;
p = t = 0L;
for (i=0; i<buf_len; i++) {
s = (int)buf[i] - 127;
t += (long)s;
p += (long)(s * s);
}
/* correct for dc offset in squares */
dc = (double)t / (double)buf_len;
err = t * 2 * dc - dc * dc * buf_len;
p -= (long)round(err);
if (!peak_hold) {
ts->avg[0] += p;
} else {
ts->avg[0] = MAX(ts->avg[0], p);
}
ts->samples += 1;
}
void frequency_range(char *arg, double crop)
/* flesh out the tunes[] for scanning */
// do we want the fewest ranges (easy) or the fewest bins (harder)?
{
char *start, *stop, *step;
int i, j, upper, lower, max_size, bw_seen, bw_used, bin_e, buf_len;
int downsample, downsample_passes;
double bin_size;
struct tuning_state *ts;
/* hacky string parsing */
start = arg;
stop = strchr(start, ':') + 1;
if (stop == (char *)1) {
fprintf(stderr, "Bad frequency range specification: %s\n", arg);
exit(1);
}
stop[-1] = '\0';
step = strchr(stop, ':') + 1;
if (step == (char *)1) {
fprintf(stderr, "Bad frequency range specification: %s\n", arg);
exit(1);
}
step[-1] = '\0';
lower = (int)atofs(start);
upper = (int)atofs(stop);
max_size = (int)atofs(step);
stop[-1] = ':';
step[-1] = ':';
downsample = 1;
downsample_passes = 0;
/* evenly sized ranges, as close to MAXIMUM_RATE as possible */
// todo, replace loop with algebra
for (i=1; i<1500; i++) {
bw_seen = (upper - lower) / i;
bw_used = (int)((double)(bw_seen) / (1.0 - crop));
if (bw_used > MAXIMUM_RATE) {
continue;}
tune_count = i;
break;
}
/* unless small bandwidth */
if (bw_used < MINIMUM_RATE) {
tune_count = 1;
downsample = MAXIMUM_RATE / bw_used;
bw_used = bw_used * downsample;
}
if (!boxcar && downsample > 1) {
downsample_passes = (int)log2(downsample);
downsample = 1 << downsample_passes;
bw_used = (int)((double)(bw_seen * downsample) / (1.0 - crop));
}
/* number of bins is power-of-two, bin size is under limit */
// todo, replace loop with log2
for (i=1; i<=21; i++) {
bin_e = i;
bin_size = (double)bw_used / (double)((1<<i) * downsample);
if (bin_size <= (double)max_size) {
break;}
}
/* unless giant bins */
if (max_size >= MINIMUM_RATE) {
bw_seen = max_size;
bw_used = max_size;
tune_count = (upper - lower) / bw_seen;
bin_e = 0;
crop = 0;
}
if (tune_count > MAX_TUNES) {
fprintf(stderr, "Error: bandwidth too wide.\n");
exit(1);
}
buf_len = 2 * (1<<bin_e) * downsample;
if (buf_len < DEFAULT_BUF_LENGTH) {
buf_len = DEFAULT_BUF_LENGTH;
}
/* build the array */
for (i=0; i<tune_count; i++) {
ts = &tunes[i];
ts->freq = lower + i*bw_seen + bw_seen/2;
ts->rate = bw_used;
ts->bin_e = bin_e;
ts->samples = 0;
ts->crop = crop;
ts->downsample = downsample;
ts->downsample_passes = downsample_passes;
ts->avg = (long*)malloc((1<<bin_e) * sizeof(long));
if (!ts->avg) {
fprintf(stderr, "Error: malloc.\n");
exit(1);
}
for (j=0; j<(1<<bin_e); j++) {
ts->avg[j] = 0L;
}
ts->buf8 = (uint8_t*)malloc(buf_len * sizeof(uint8_t));
if (!ts->buf8) {
fprintf(stderr, "Error: malloc.\n");
exit(1);
}
ts->buf_len = buf_len;
}
/* report */
fprintf(stderr, "Number of frequency hops: %i\n", tune_count);
fprintf(stderr, "Dongle bandwidth: %iHz\n", bw_used);
fprintf(stderr, "Downsampling by: %ix\n", downsample);
fprintf(stderr, "Cropping by: %0.2f%%\n", crop*100);
fprintf(stderr, "Total FFT bins: %i\n", tune_count * (1<<bin_e));
fprintf(stderr, "Logged FFT bins: %i\n", \
(int)((double)(tune_count * (1<<bin_e)) * (1.0-crop)));
fprintf(stderr, "FFT bin size: %0.2fHz\n", bin_size);
fprintf(stderr, "Buffer size: %i bytes (%0.2fms)\n", buf_len, 1000 * 0.5 * (float)buf_len / (float)bw_used);
}
void retune(rtlsdr_dev_t *d, int freq)
{
uint8_t dump[BUFFER_DUMP];
int n_read;
rtlsdr_set_center_freq(d, (uint32_t)freq);
/* wait for settling and flush buffer */
usleep(5000);
rtlsdr_read_sync(d, &dump, BUFFER_DUMP, &n_read);
if (n_read != BUFFER_DUMP) {
fprintf(stderr, "Error: bad retune.\n");}
}
void fifth_order(int16_t *data, int length)
/* for half of interleaved data */
{
int i;
int a, b, c, d, e, f;
a = data[0];
b = data[2];
c = data[4];
d = data[6];
e = data[8];
f = data[10];
/* a downsample should improve resolution, so don't fully shift */
/* ease in instead of being stateful */
data[0] = ((a+b)*10 + (c+d)*5 + d + f) >> 4;
data[2] = ((b+c)*10 + (a+d)*5 + e + f) >> 4;
data[4] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
for (i=12; i<length; i+=4) {
a = c;
b = d;
c = e;
d = f;
e = data[i-2];
f = data[i];
data[i/2] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
}
}
void remove_dc(int16_t *data, int length)
/* works on interleaved data */
{
int i;
int16_t ave;
long sum = 0L;
for (i=0; i < length; i+=2) {
sum += data[i];
}
ave = (int16_t)(sum / (long)(length));
if (ave == 0) {
return;}
for (i=0; i < length; i+=2) {
data[i] -= ave;
}
}
void generic_fir(int16_t *data, int length, int *fir)
/* Okay, not at all generic. Assumes length 9, fix that eventually. */
{
int d, temp, sum;
int hist[9] = {0,};
/* cheat on the beginning, let it go unfiltered */
for (d=0; d<18; d+=2) {
hist[d/2] = data[d];
}
for (d=18; d<length; d+=2) {
temp = data[d];
sum = 0;
sum += (hist[0] + hist[8]) * fir[1];
sum += (hist[1] + hist[7]) * fir[2];
sum += (hist[2] + hist[6]) * fir[3];
sum += (hist[3] + hist[5]) * fir[4];
sum += hist[4] * fir[5];
data[d] = (int16_t)(sum >> 15) ;
hist[0] = hist[1];
hist[1] = hist[2];
hist[2] = hist[3];
hist[3] = hist[4];
hist[4] = hist[5];
hist[5] = hist[6];
hist[6] = hist[7];
hist[7] = hist[8];
hist[8] = temp;
}
}
void downsample_iq(int16_t *data, int length)
{
fifth_order(data, length);
//remove_dc(data, length);
fifth_order(data+1, length-1);
//remove_dc(data+1, length-1);
}
long real_conj(int16_t real, int16_t imag)
/* real(n * conj(n)) */
{
return ((long)real*(long)real + (long)imag*(long)imag);
}
void scanner(void)
{
int i, j, j2, f, n_read, offset, bin_e, bin_len, buf_len, ds, ds_p;
int32_t w;
struct tuning_state *ts;
bin_e = tunes[0].bin_e;
bin_len = 1 << bin_e;
buf_len = tunes[0].buf_len;
for (i=0; i<tune_count; i++) {
if (do_exit >= 2)
{return;}
ts = &tunes[i];
f = (int)rtlsdr_get_center_freq(dev);
if (f != ts->freq) {
retune(dev, ts->freq);}
rtlsdr_read_sync(dev, ts->buf8, buf_len, &n_read);
if (n_read != buf_len) {
fprintf(stderr, "Error: dropped samples.\n");}
/* rms */
if (bin_len == 1) {
rms_power(ts);
continue;
}
/* prep for fft */
for (j=0; j<buf_len; j++) {
fft_buf[j] = (int16_t)ts->buf8[j] - 127;
}
ds = ts->downsample;
ds_p = ts->downsample_passes;
if (boxcar && ds > 1) {
j=2, j2=0;
while (j < buf_len) {
fft_buf[j2] += fft_buf[j];
fft_buf[j2+1] += fft_buf[j+1];
fft_buf[j] = 0;
fft_buf[j+1] = 0;
j += 2;
if (j % (ds*2) == 0) {
j2 += 2;}
}
} else if (ds_p) { /* recursive */
for (j=0; j < ds_p; j++) {
downsample_iq(fft_buf, buf_len >> j);
}
/* droop compensation */
if (comp_fir_size == 9 && ds_p <= CIC_TABLE_MAX) {
generic_fir(fft_buf, buf_len >> j, cic_9_tables[ds_p]);
generic_fir(fft_buf+1, (buf_len >> j)-1, cic_9_tables[ds_p]);
}
}
remove_dc(fft_buf, buf_len / ds);
remove_dc(fft_buf+1, (buf_len / ds) - 1);
/* window function and fft */
for (offset=0; offset<(buf_len/ds); offset+=(2*bin_len)) {
// todo, let rect skip this
for (j=0; j<bin_len; j++) {
w = (int32_t)fft_buf[offset+j*2];
w *= (int32_t)(window_coefs[j]);
//w /= (int32_t)(ds);
fft_buf[offset+j*2] = (int16_t)w;
w = (int32_t)fft_buf[offset+j*2+1];
w *= (int32_t)(window_coefs[j]);
//w /= (int32_t)(ds);
fft_buf[offset+j*2+1] = (int16_t)w;
}
fix_fft(fft_buf+offset, bin_e);
if (!peak_hold) {
for (j=0; j<bin_len; j++) {
ts->avg[j] += real_conj(fft_buf[offset+j*2], fft_buf[offset+j*2+1]);
}
} else {
for (j=0; j<bin_len; j++) {
ts->avg[j] = MAX(real_conj(fft_buf[offset+j*2], fft_buf[offset+j*2+1]), ts->avg[j]);
}
}
ts->samples += ds;
}
}
}
void csv_dbm(struct tuning_state *ts)
{
int i, len, ds, i1, i2, bw2, bin_count;
long tmp;
double dbm;
len = 1 << ts->bin_e;
ds = ts->downsample;
/* fix FFT stuff quirks */
if (ts->bin_e > 0) {
/* nuke DC component (not effective for all windows) */
ts->avg[0] = ts->avg[1];
/* FFT is translated by 180 degrees */
for (i=0; i<len/2; i++) {
tmp = ts->avg[i];
ts->avg[i] = ts->avg[i+len/2];
ts->avg[i+len/2] = tmp;
}
}
/* Hz low, Hz high, Hz step, samples, dbm, dbm, ... */
bin_count = (int)((double)len * (1.0 - ts->crop));
bw2 = (int)(((double)ts->rate * (double)bin_count) / (len * 2 * ds));
fprintf(file, "%i, %i, %.2f, %i, ", ts->freq - bw2, ts->freq + bw2,
(double)ts->rate / (double)(len*ds), ts->samples);
// something seems off with the dbm math
i1 = 0 + (int)((double)len * ts->crop * 0.5);
i2 = (len-1) - (int)((double)len * ts->crop * 0.5);
for (i=i1; i<=i2; i++) {
dbm = (double)ts->avg[i];
dbm /= (double)ts->rate;
dbm /= (double)ts->samples;
dbm = 10 * log10(dbm);
fprintf(file, "%.2f, ", dbm);
}
dbm = (double)ts->avg[i2] / ((double)ts->rate * (double)ts->samples);
if (ts->bin_e == 0) {
dbm = ((double)ts->avg[0] / \
((double)ts->rate * (double)ts->samples));}
dbm = 10 * log10(dbm);
fprintf(file, "%.2f\n", dbm);
for (i=0; i<len; i++) {
ts->avg[i] = 0L;
}
ts->samples = 0;
}
int main(int argc, char **argv)
{
#ifndef _WIN32
struct sigaction sigact;
#endif
char *filename = NULL;
int i, length, r, opt, wb_mode = 0;
int f_set = 0;
int gain = AUTO_GAIN; // tenths of a dB
int dev_index = 0;
int dev_given = 0;
int ppm_error = 0;
int interval = 10;
int fft_threads = 1;
int smoothing = 0;
int single = 0;
int direct_sampling = 0;
int offset_tuning = 0;
int enable_biastee = 0;
double crop = 0.0;
char *freq_optarg;
time_t next_tick;
time_t time_now;
time_t exit_time = 0;
char t_str[50];
struct tm *cal_time;
double (*window_fn)(int, int) = rectangle;
freq_optarg = "";
while ((opt = getopt(argc, argv, "f:i:s:t:d:g:p:e:w:c:F:1PDOhT")) != -1) {
switch (opt) {
case 'f': // lower:upper:bin_size
freq_optarg = strdup(optarg);
f_set = 1;
break;
case 'd':
dev_index = verbose_device_search(optarg);
dev_given = 1;
break;
case 'g':
gain = (int)(atof(optarg) * 10);
break;
case 'c':
crop = atofp(optarg);
break;
case 'i':
interval = (int)round(atoft(optarg));
break;
case 'e':
exit_time = (time_t)((int)round(atoft(optarg)));
break;
case 's':
if (strcmp("avg", optarg) == 0) {
smoothing = 0;}
if (strcmp("iir", optarg) == 0) {
smoothing = 1;}
break;
case 'w':
if (strcmp("rectangle", optarg) == 0) {
window_fn = rectangle;}
if (strcmp("hamming", optarg) == 0) {
window_fn = hamming;}
if (strcmp("blackman", optarg) == 0) {
window_fn = blackman;}
if (strcmp("blackman-harris", optarg) == 0) {
window_fn = blackman_harris;}
if (strcmp("hann-poisson", optarg) == 0) {
window_fn = hann_poisson;}
if (strcmp("youssef", optarg) == 0) {
window_fn = youssef;}
if (strcmp("kaiser", optarg) == 0) {
window_fn = kaiser;}
if (strcmp("bartlett", optarg) == 0) {
window_fn = bartlett;}
break;
case 't':
fft_threads = atoi(optarg);
break;
case 'p':
ppm_error = atoi(optarg);
break;
case '1':
single = 1;
break;
case 'P':
peak_hold = 1;
break;
case 'D':
direct_sampling = 1;
break;
case 'O':
offset_tuning = 1;
break;
case 'F':
boxcar = 0;
comp_fir_size = atoi(optarg);
break;
case 'T':
enable_biastee = 1;
break;
case 'h':
default:
usage();
break;
}
}
if (!f_set) {
fprintf(stderr, "No frequency range provided.\n");
exit(1);
}
if ((crop < 0.0) || (crop > 1.0)) {
fprintf(stderr, "Crop value outside of 0 to 1.\n");
exit(1);
}
frequency_range(freq_optarg, crop);
if (tune_count == 0) {
usage();}
if (argc <= optind) {
filename = "-";
} else {
filename = argv[optind];
}
if (interval < 1) {
interval = 1;}
fprintf(stderr, "Reporting every %i seconds\n", interval);
if (!dev_given) {
dev_index = verbose_device_search("0");
}
if (dev_index < 0) {
exit(1);
}
r = rtlsdr_open(&dev, (uint32_t)dev_index);
if (r < 0) {
fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dev_index);
exit(1);
}
#ifndef _WIN32
sigact.sa_handler = sighandler;
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = 0;
sigaction(SIGINT, &sigact, NULL);
sigaction(SIGTERM, &sigact, NULL);
sigaction(SIGQUIT, &sigact, NULL);
sigaction(SIGPIPE, &sigact, NULL);
#else
SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
#endif
if (direct_sampling) {
verbose_direct_sampling(dev, 1);
}
if (offset_tuning) {
verbose_offset_tuning(dev);
}
/* Set the tuner gain */
if (gain == AUTO_GAIN) {
verbose_auto_gain(dev);
} else {
gain = nearest_gain(dev, gain);
verbose_gain_set(dev, gain);
}
verbose_ppm_set(dev, ppm_error);
rtlsdr_set_bias_tee(dev, enable_biastee);
if (enable_biastee)
fprintf(stderr, "activated bias-T on GPIO PIN 0\n");
if (strcmp(filename, "-") == 0) { /* Write log to stdout */
file = stdout;
#ifdef _WIN32
// Is this necessary? Output is ascii.
_setmode(_fileno(file), _O_BINARY);
#endif
} else {
file = fopen(filename, "wb");
if (!file) {
fprintf(stderr, "Failed to open %s\n", filename);
exit(1);
}
}
/* Reset endpoint before we start reading from it (mandatory) */
verbose_reset_buffer(dev);
/* actually do stuff */
rtlsdr_set_sample_rate(dev, (uint32_t)tunes[0].rate);
sine_table(tunes[0].bin_e);
next_tick = time(NULL) + interval;
if (exit_time) {
exit_time = time(NULL) + exit_time;}
fft_buf = malloc(tunes[0].buf_len * sizeof(int16_t));
length = 1 << tunes[0].bin_e;
window_coefs = malloc(length * sizeof(int));
for (i=0; i<length; i++) {
window_coefs[i] = (int)(256*window_fn(i, length));
}
while (!do_exit) {
scanner();
time_now = time(NULL);
if (time_now < next_tick) {
continue;}
// time, Hz low, Hz high, Hz step, samples, dbm, dbm, ...
cal_time = localtime(&time_now);
strftime(t_str, 50, "%Y-%m-%d, %H:%M:%S", cal_time);
for (i=0; i<tune_count; i++) {
fprintf(file, "%s, ", t_str);
csv_dbm(&tunes[i]);
}
fflush(file);
while (time(NULL) >= next_tick) {
next_tick += interval;}
if (single) {
do_exit = 1;}
if (exit_time && time(NULL) >= exit_time) {
do_exit = 1;}
}
/* clean up */
if (do_exit) {
fprintf(stderr, "\nUser cancel, exiting...\n");}
else {
fprintf(stderr, "\nLibrary error %d, exiting...\n", r);}
if (file != stdout) {
fclose(file);}
rtlsdr_close(dev);
free(fft_buf);
free(window_coefs);
//for (i=0; i<tune_count; i++) {
// free(tunes[i].avg);
// free(tunes[i].buf8);
//}
return r >= 0 ? r : -r;
}
// vim: tabstop=8:softtabstop=8:shiftwidth=8:noexpandtab