/* * rtl-sdr, a poor man's SDR using a Realtek RTL2832 based DVB-stick * Copyright (C) 2012 by Steve Markgraf * * 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 . */ #include #include #include #include #include #include #include #include "rtl-sdr.h" #define READLEN (16 * 16384) static int do_exit = 0; void usage(void) { printf("rtl-sdr, an I/Q recorder for RTL2832 based USB-sticks\n\n" "Usage:\t -f frequency to tune to [Hz]\n" "\t[-s samplerate (default: 2048000 Hz)]\n" "\toutput filename\n"); exit(1); } static void sighandler(int signum) { do_exit = 1; } int main(int argc, char **argv) { struct sigaction sigact; int r, opt; char *filename; uint32_t frequency = 0, samp_rate = 2048000; uint8_t buffer[READLEN]; uint32_t n_read; FILE *file; rtlsdr_dev_t *dev = NULL; while ((opt = getopt(argc, argv, "f:s:")) != -1) { switch (opt) { case 'f': frequency = atoi(optarg); break; case 's': samp_rate = atoi(optarg); break; default: usage(); break; } } if (argc <= optind) { usage(); } else { filename = argv[optind]; } rtlsdr_init(); int device_count = rtlsdr_get_device_count(); if (!device_count) { fprintf(stderr, "No supported devices found.\n"); exit(1); } printf("Found %d device(s).\n", device_count); dev = rtlsdr_open(0); /* open the first device */ if (NULL == dev) { fprintf(stderr, "Failed to open rtlsdr device.\n"); exit(1); } sigact.sa_handler = sighandler; sigemptyset(&sigact.sa_mask); sigact.sa_flags = 0; sigaction(SIGINT, &sigact, NULL); sigaction(SIGTERM, &sigact, NULL); sigaction(SIGQUIT, &sigact, NULL); /* Set the sample rate */ r = rtlsdr_set_sample_rate(dev, samp_rate); if (r < 0) { fprintf(stderr, "WARNING: Failed to set sample rate.\n"); } /* Set the frequency */ r = rtlsdr_set_center_freq(dev, frequency); if (r < 0) { fprintf(stderr, "WARNING: Failed to set center freq.\n"); } file = fopen(filename, "wb"); if (!file) { printf("Failed to open %s\n", filename); goto out; } /* Reset endpoint before we start reading from it */ r = rtlsdr_reset_buffer(dev); if (r < 0) { fprintf(stderr, "WARNING: Failed to reset buffers.\n"); } printf("Reading samples...\n"); while (!do_exit) { r = rtlsdr_read_sync(dev, buffer, READLEN, &n_read); if (r < 0) { fprintf(stderr, "WARNING: sync read failed.\n"); } fwrite(buffer, n_read, 1, file); if (n_read < READLEN) { printf("Short read, samples lost, exiting!\n"); break; } } fclose(file); rtlsdr_exit(); out: return r >= 0 ? r : -r; }