/
rx.c
134 lines (108 loc) · 3.11 KB
/
rx.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <signal.h>
#include <rtl-sdr.h>
rtlsdr_dev_t* rtlsdr;
FILE* outf;
int async_started;
int quit_please;
int buffers_received;
void sighandler(int signal)
{
printf("Caught ctrl-c, cleaning up.\n");
quit_please = 1;
if(!async_started) {
if(outf != NULL) {
fclose(outf);
}
exit(0);
}
}
void read_callback(unsigned char* buf, uint32_t len, void* ctx)
{
printf(".");
fflush(stdout);
fwrite(buf, 1, len, outf);
buffers_received++;
if(quit_please || buffers_received == 20) {
printf("Final callback, shutting down.\n");
printf("Closing output file...\n");
fclose(outf);
printf("Stopping RTL-SDR streaming...\n");
rtlsdr_cancel_async(rtlsdr);
exit(0);
printf("Closing RTL-SDR...\n");
rtlsdr_close(rtlsdr);
exit(0);
}
}
int main(int argc, char* argv[])
{
int rv;
async_started = 0;
quit_please = 0;
buffers_received = 0;
signal(SIGINT, sighandler);
printf("Opening output file...\n");
outf = fopen("rtlsdr_out.bin", "w");
if(outf == NULL) {
printf("Error opening output file: %d.\nExiting.\n", errno);
return 1;
}
rv = rtlsdr_get_device_count();
if(rv == 0) {
printf("No RTL-SDR devices found, exiting.\n");
return 2;
}
printf("Found %d device(s).\n", rv);
printf("Opening the first, '%s'...\n", rtlsdr_get_device_name(0));
rv = rtlsdr_open(&rtlsdr, 0);
if(rv != 0) {
printf("Error opening device: %d\nExiting.\n", rv);
return 3;
}
printf("Setting frequency to 315MHz...\n");
rv = rtlsdr_set_center_freq(rtlsdr, 315000000);
if(rv != 0) {
printf("Error setting frequency: %d\nExiting.\n", rv);
return 4;
}
printf("Frequency set to %uHz.\n", rtlsdr_get_center_freq(rtlsdr));
printf("Setting gain mode to automatic.\n");
rv = rtlsdr_set_tuner_gain_mode(rtlsdr, 0);
if(rv != 0) {
printf("Error setting gain mode: %d\nExiting.\n", rv);
return 5;
}
printf("Gain currently set to %d.\n", rtlsdr_get_tuner_gain(rtlsdr));
printf("Setting sample rate to 240kHz...\n");
rv = rtlsdr_set_sample_rate(rtlsdr, 240000);
if(rv != 0) {
printf("Error setting sample rate: %d\nExiting.\n", rv);
return 6;
}
printf("Sample rate set to %u.\n", rtlsdr_get_sample_rate(rtlsdr));
printf("Setting AGC on...\n");
rv = rtlsdr_set_agc_mode(rtlsdr, 1);
if(rv != 0) {
printf("Error setting AGC: %d\nExiting.\n", rv);
return 7;
}
printf("Clearing buffer and streaming data...\n");
rv = rtlsdr_reset_buffer(rtlsdr);
if(rv != 0) {
printf("Error clearing buffer: %d\nExiting.\n", rv);
return 8;
}
async_started = 1;
rv = rtlsdr_read_async(rtlsdr, read_callback, NULL, 0, 0);
if(rv != 0) {
printf("Error setting up async streaming: %d\nExiting.\n", rv);
return 9;
}
rtlsdr_cancel_async(rtlsdr);
rtlsdr_close(rtlsdr);
return 0;
}