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add commandline option for setting the sample rate

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Signed-off-by: Steve Markgraf <steve@steve-m.de>
This commit is contained in:
Steve Markgraf 2012-03-13 23:18:25 +01:00
parent 5a4fd14581
commit 8dc13ea3ea
1 changed files with 23 additions and 11 deletions
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34
src/main.c
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@ -21,6 +21,7 @@
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <unistd.h>
#include <libusb.h>
@ -40,6 +41,8 @@
#define NOXON_VID 0x0ccd
#define NOXON_PID 0x00b3
#define CRYSTAL_FREQ 28800000
static struct libusb_device_handle *devh = NULL;
static int do_exit = 0;
@ -214,12 +217,20 @@ void demod_write_reg(uint8_t page, uint16_t addr, uint16_t val, uint8_t len)
demod_read_reg(0x0a, 0x01, 1);
}
void set_resampler(uint32_t rsamp_ratio)
void set_samp_rate(uint32_t samp_rate)
{
uint16_t tmp;
rsamp_ratio <<= 2;
uint32_t rsamp_ratio;
tmp = (rsamp_ratio >> 16) & 0xffff;
/* check for the maximum rate the resampler supports */
if (samp_rate > 3200000)
samp_rate = 3200000;
printf("Setting sample rate: %i Hz\n", samp_rate);
rsamp_ratio = (CRYSTAL_FREQ * pow(2, 22)) / samp_rate;
rsamp_ratio &= ~3;
tmp = (rsamp_ratio >> 16);
demod_write_reg(1, 0x9f, tmp, 2);
tmp = rsamp_ratio & 0xffff;
demod_write_reg(1, 0xa1, tmp, 2);
@ -265,10 +276,6 @@ void rtl_init(void)
for (i = 0; i < sizeof (fir_coeff); i++)
demod_write_reg(1, 0x1c + i, fir_coeff[i], 1);
/* TODO setting resampler test value, max value is 0xC99999,
* value for DAB/FM is 0xE10000*/
set_resampler(1 << 24);
demod_write_reg(0, 0x19, 0x25, 1);
/* init FSM state-holding register */
@ -295,7 +302,7 @@ void tuner_init(int frequency)
switch (tuner_type) {
case TUNER_E4000:
e4000_Initialize(1);
e4000_SetBandwidthHz(1, 80000);
e4000_SetBandwidthHz(1, 8000000);
e4000_SetRfFreqHz(1, frequency);
break;
case TUNER_FC0013:
@ -314,7 +321,8 @@ void tuner_init(int frequency)
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"
"Usage:\t -f frequency to tune to [Hz]\n"
"\t[-s samplerate (default: 2048000 Hz)]\n"
"\toutput filename\n");
exit(1);
}
@ -329,16 +337,19 @@ int main(int argc, char **argv)
struct sigaction sigact;
int r, opt;
char *filename;
unsigned int frequency = 0;
uint32_t frequency = 0, samp_rate = 2048000;
uint8_t buffer[READLEN];
int n_read;
FILE *file;
while ((opt = getopt(argc, argv, "f:")) != -1) {
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;
@ -378,6 +389,7 @@ int main(int argc, char **argv)
/* Initialize the RTL2832 */
rtl_init();
set_samp_rate(samp_rate);
/* Initialize tuner & set frequency */
tuner_init(frequency);