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Diffstat (limited to 'test/sdr_fm.c')
| -rw-r--r-- | test/sdr_fm.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/test/sdr_fm.c b/test/sdr_fm.c new file mode 100644 index 0000000..7d99f10 --- /dev/null +++ b/test/sdr_fm.c @@ -0,0 +1,264 @@ +#include <stdio.h> +#include <stdlib.h> +#include <getopt.h> +#include <string.h> +#include <math.h> +#include <unistd.h> + +#include <hw/hw.h> +#include <hw/sdr.h> + +#define SAMPLE_RATE 1000000 +#define RESAMPLE_RATE 50000 + +#define CENTER_FREQ 446500000 +#define FFT_LEVEL 10 +#define FFT_SIZE (1 << FFT_LEVEL) +#define SAMPLE_LENGHT (2 * FFT_SIZE) +#define PRESCALE 8 +#define POSTSCALE 2 + + +void helper( char *exec_name ) +{ + const char help_str[]="Usage: ./%s [OPTIONS]\n\ +-f [FREQ] - set center frequency\n\ +-s [SAMPLE] - set sample rate\n\ +-d [DEVICE] - choose device\n\ +-r [RESAMPE] - set resample rate\n\ +-? - print help\n\ +"; + printf( help_str, exec_name ); +} + +unsigned int super_atan( signed int x1, signed int y1 ) +{ + // Fast XY vector to integer degree algorithm - Jan 2011 www.RomanBlack.com + // Converts any XY values including 0 to a degree value that should be + // within +/- 1 degree of the accurate value without needing + // large slow trig functions like ArcTan() or ArcCos(). + // NOTE! at least one of the X or Y values must be non-zero! + // This is the full version, for all 4 quadrants and will generate + // the angle in integer degrees from 0-360. + // Any values of X and Y are usable including negative values provided + // they are between -1456 and 1456 so the 16bit multiply does not overflow. + + unsigned char negflag; + unsigned char tempdegree; + unsigned char comp; + unsigned int degree; // this will hold the result + signed int x=x1; // these hold the XY vector at the start + signed int y=y1; // (and they will be destroyed) + unsigned int ux; + unsigned int uy; + + // Save the sign flags then remove signs and get XY as unsigned ints + negflag = 0; + if(x < 0) + { + negflag += 0x01; // x flag bit + x = (0 - x); // is now + + } + ux = x; // copy to unsigned var before multiply + if(y < 0) + { + negflag += 0x02; // y flag bit + y = (0 - y); // is now + + } + uy = y; // copy to unsigned var before multiply + + // 1. Calc the scaled "degrees" + if(ux > uy) + { + degree = (uy * 45) / ux; // degree result will be 0-45 range + negflag += 0x10; // octant flag bit + } + else + { + degree = (ux * 45) / uy; // degree result will be 0-45 range + } + + // 2. Compensate for the 4 degree error curve + comp = 0; + tempdegree = degree; // use an unsigned char for speed! + if(tempdegree > 22) // if top half of range + { + if(tempdegree <= 44) comp++; + if(tempdegree <= 41) comp++; + if(tempdegree <= 37) comp++; + if(tempdegree <= 32) comp++; // max is 4 degrees compensated + } + else // else is lower half of range + { + if(tempdegree >= 2) comp++; + if(tempdegree >= 6) comp++; + if(tempdegree >= 10) comp++; + if(tempdegree >= 15) comp++; // max is 4 degrees compensated + } + degree += comp; // degree is now accurate to +/- 1 degree! + + // Invert degree if it was X>Y octant, makes 0-45 into 90-45 + if(negflag & 0x10) degree = (90 - degree); + + // 3. Degree is now 0-90 range for this quadrant, + // need to invert it for whichever quadrant it was in + if(negflag & 0x02) // if -Y + { + if(negflag & 0x01) // if -Y -X + degree = (180 + degree); + else // else is -Y +X + degree = (180 - degree); + } + else // else is +Y + { + if(negflag & 0x01) // if +Y -X + degree = (360 - degree); + } + return degree; +} + +/* +Page about div +http://bisqwit.iki.fi/story/howto/bitmath/#DivAndModDivisionAndModulo +*/ + +uint8_t super_div20u8( uint16_t num ) +{ + uint16_t a = num; + uint16_t b = 20; + uint16_t r = 0; + uint16_t m = 1; + while ( b < a ) + { + b = b << 1; + m = m << 1; + } + do + { + if ( a >= b ) + { + a = a - b; + r = r + m; + } + b = b >> 1; + m = m >> 1; + } while ( m != 0 ); + return (uint8_t)r; +} + +void rotate_90(uint8_t *buf, uint32_t len) +/* 90 rotation is 1+0j, 0+1j, -1+0j, 0-1j + or [0, 1, -3, 2, -4, -5, 7, -6] */ +{ + uint32_t i; + uint8_t tmp; + for (i=0; i<len; i+=8) { + /* uint8_t negation = 255 - x */ + tmp = 255 - buf[i+3]; + buf[i+3] = buf[i+2]; + buf[i+2] = tmp; + + buf[i+4] = 255 - buf[i+4]; + buf[i+5] = 255 - buf[i+5]; + + tmp = 255 - buf[i+6]; + buf[i+6] = buf[i+7]; + buf[i+7] = tmp; + } +} + +int main( int argc, char **argv ) +{ + + int c; + int ret; + + uint8_t *buf, *sample_buf; + int buf_len, sample_len; + + //commandline config params + int config_device = 0; + uint32_t config_freq = CENTER_FREQ; + uint32_t config_sample_rate = SAMPLE_RATE; + uint32_t config_resample_rate = RESAMPLE_RATE; + + sdr_t *sdr = NULL; + dongle_t *dongle = NULL; + + // get all argument configs + opterr = 0; + while ( (c = getopt(argc, argv, "f:s:d:")) != -1 ) + { + switch ( c ) + { + case 'f': + config_freq = atoi( optarg ); + break; + case 's': + config_sample_rate = atoi( optarg ); + break; + case 'd': + //printf(" %s \n", optarg); + config_device = atoi( optarg ); + break; + case '?': + helper( argv[0] ); + break; + case ':': + printf("\n"); + break; + default: + printf("Unknow option\n"); + return -1; + } + } + + if ( (sdr = sdr_init()) == NULL ) + { + printf("Cannot init sdr manager\n"); + sdr = NULL; + goto main_exit; + } + + if ( sdr_open_device( sdr, config_device ) != 0 ) + { + printf("MAIN:Cannot open device %d\n", config_device); + sdr->dongle = NULL; + goto main_exit; + } + + dongle = sdr_get_device_id( sdr, config_device ); + ret = 0; + ret != dongle_set_freq( dongle, config_freq ); + ret != dongle_set_sample_rate( dongle, config_sample_rate ); + ret != dongle_set_gain( dongle, 0 ); + ret != dongle_set_agc( dongle, 40 ); + if (ret != 0) + { + printf("Cannot properly config device\n"); + } + + sample_len = SAMPLE_LENGHT; + sample_buf = malloc( sample_len ); + + while ( 1 ) + { + //read plain samples + dongle_read_samples( dongle, sample_buf, sample_len ); + //delay + //rotate by 90 degrees + rotate_90( sample_buf, sample_len ); + //downsample + //sample rate 1Mhz downsample to 50Khz + + //play + + usleep(10000); + //printf("Sample\n"); + } + +main_exit: + sdr_close(0); + + return 0; +}
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