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Merge pull request #993 from greatscottgadgets/sweep-num_samples

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hackrf_sweep: simplify dwell time, bin width, and time stamps
This commit is contained in:
Mike Walters
2021-11-15 21:59:12 +00:00
committed by GitHub
parent bd4b786136 c8695e0a44
commit 01675961cb
1 changed files with 21 additions and 33 deletions
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54
host/hackrf-tools/src/hackrf_sweep.c
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@ -107,7 +107,6 @@ int gettimeofday(struct timeval *tv, void* ignored) {
#define m_sleep(a) usleep((a*1000))
#endif
uint32_t num_samples = SAMPLES_PER_BLOCK;
uint32_t num_sweeps = 0;
int num_ranges = 0;
uint16_t frequencies[MAX_SWEEP_RANGES*2];
@ -171,7 +170,6 @@ volatile uint64_t sweep_count = 0;
struct timeval time_start;
struct timeval t_start;
struct timeval time_stamp;
bool amp = false;
uint32_t amp_enable;
@ -257,14 +255,6 @@ int rx_callback(hackrf_transfer* transfer) {
}
}
sweep_started = true;
time_stamp = usb_transfer_time;
time_stamp.tv_usec +=
(uint64_t)(num_samples + THROWAWAY_BLOCKS * SAMPLES_PER_BLOCK)
* j * FREQ_ONE_MHZ / DEFAULT_SAMPLE_RATE_HZ;
if(999999 < time_stamp.tv_usec) {
time_stamp.tv_sec += time_stamp.tv_usec / 1000000;
time_stamp.tv_usec = time_stamp.tv_usec % 1000000;
}
}
if(do_exit) {
return 0;
@ -320,12 +310,12 @@ int rx_callback(hackrf_transfer* transfer) {
ifftwIn[ifft_idx + i][1] = fftwOut[i + 1 + (fftSize/8)][1];
}
} else {
time_t time_stamp_seconds = time_stamp.tv_sec;
time_t time_stamp_seconds = usb_transfer_time.tv_sec;
fft_time = localtime(&time_stamp_seconds);
strftime(time_str, 50, "%Y-%m-%d, %H:%M:%S", fft_time);
fprintf(outfile, "%s.%06ld, %" PRIu64 ", %" PRIu64 ", %.2f, %u",
time_str,
(long int)time_stamp.tv_usec,
(long int)usb_transfer_time.tv_usec,
(uint64_t)(frequency),
(uint64_t)(frequency+DEFAULT_SAMPLE_RATE_HZ/4),
fft_bin_width,
@ -336,7 +326,7 @@ int rx_callback(hackrf_transfer* transfer) {
fprintf(outfile, "\n");
fprintf(outfile, "%s.%06ld, %" PRIu64 ", %" PRIu64 ", %.2f, %u",
time_str,
(long int)time_stamp.tv_usec,
(long int)usb_transfer_time.tv_usec,
(uint64_t)(frequency+(DEFAULT_SAMPLE_RATE_HZ/2)),
(uint64_t)(frequency+((DEFAULT_SAMPLE_RATE_HZ*3)/4)),
fft_bin_width,
@ -359,8 +349,7 @@ static void usage() {
fprintf(stderr, "\t[-p antenna_enable] # Antenna port power, 1=Enable, 0=Disable\n");
fprintf(stderr, "\t[-l gain_db] # RX LNA (IF) gain, 0-40dB, 8dB steps\n");
fprintf(stderr, "\t[-g gain_db] # RX VGA (baseband) gain, 0-62dB, 2dB steps\n");
fprintf(stderr, "\t[-n num_samples] # Number of samples per frequency, 8192-4294967296\n");
fprintf(stderr, "\t[-w bin_width] # FFT bin width (frequency resolution) in Hz\n");
fprintf(stderr, "\t[-w bin_width] # FFT bin width (frequency resolution) in Hz, 2445-5000000\n");
fprintf(stderr, "\t[-1] # one shot mode\n");
fprintf(stderr, "\t[-N num_sweeps] # Number of sweeps to perform\n");
fprintf(stderr, "\t[-B] # binary output\n");
@ -458,10 +447,6 @@ int main(int argc, char** argv) {
result = parse_u32(optarg, &vga_gain);
break;
case 'n':
result = parse_u32(optarg, &num_samples);
break;
case 'N':
finite_mode = true;
result = parse_u32(optarg, &num_sweeps);
@ -512,16 +497,6 @@ int main(int argc, char** argv) {
if (vga_gain % 2)
fprintf(stderr, "warning: vga_gain (-g) must be a multiple of 2\n");
if (num_samples % SAMPLES_PER_BLOCK) {
fprintf(stderr, "warning: num_samples (-n) must be a multiple of 8192\n");
return EXIT_FAILURE;
}
if (num_samples < SAMPLES_PER_BLOCK) {
fprintf(stderr, "warning: num_samples (-n) must be at least 8192\n");
return EXIT_FAILURE;
}
if( amp ) {
if( amp_enable > 1 ) {
fprintf(stderr, "argument error: amp_enable shall be 0 or 1.\n");
@ -554,15 +529,28 @@ int main(int argc, char** argv) {
return EXIT_FAILURE;
}
/*
* The FFT bin width must be no more than a quarter of the sample rate
* for interleaved mode. With our fixed sample rate of 20 Msps, that
* results in a maximum bin width of 5000000 Hz.
*/
if(4 > fftSize) {
fprintf(stderr,
"argument error: FFT bin width (-w) must be no more than one quarter the sample rate\n");
"argument error: FFT bin width (-w) must be no more than 5000000\n");
return EXIT_FAILURE;
}
if(8184 < fftSize) {
/*
* The maximum number of FFT bins we support is equal to the number of
* samples in a block. Each block consists of 16384 bytes minus 10
* bytes for the frequency header, leaving room for 8187 two-byte
* samples. As we pad fftSize up to the next odd multiple of four, this
* makes our maximum supported fftSize 8180. With our fixed sample
* rate of 20 Msps, that results in a minimum bin width of 2445 Hz.
*/
if(8180 < fftSize) {
fprintf(stderr,
"argument error: FFT bin width (-w) too small, resulted in more than 8184 FFT bins\n");
"argument error: FFT bin width (-w) must be no less than 2445\n");
return EXIT_FAILURE;
}
@ -674,7 +662,7 @@ int main(int argc, char** argv) {
ifftwPlan = fftwf_plan_dft_1d(fftSize * step_count, ifftwIn, ifftwOut, FFTW_BACKWARD, FFTW_MEASURE);
}
result = hackrf_init_sweep(device, frequencies, num_ranges, num_samples * 2,
result = hackrf_init_sweep(device, frequencies, num_ranges, BYTES_PER_BLOCK,
TUNE_STEP * FREQ_ONE_MHZ, OFFSET, INTERLEAVED);
if( result != HACKRF_SUCCESS ) {
fprintf(stderr, "hackrf_init_sweep() failed: %s (%d)\n",