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/*
* Copyright 2015 Ettus Research LLC
* Copyright 2018 Ettus Research, a National Instruments Company
*
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#include <uhd.h>
#include "getopt.h"
#include <math.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define EXECUTE_OR_GOTO(label, ...) \
if(__VA_ARGS__){ \
return_code = EXIT_FAILURE; \
goto label; \
}
void print_help(void){
fprintf(stderr, "tx_samples_c - A simple TX example using UHD's C API\n\n"
"Options:\n"
" -a (device args)\n"
" -f (frequency in Hz)\n"
" -r (sample rate in Hz)\n"
" -g (gain)\n"
" -n (number of samples to transmit)\n"
" -v (enable verbose prints)\n"
" -h (print this help message)\n");
}
bool stop_signal_called = false;
void sigint_handler(int code){
(void)code;
stop_signal_called = true;
}
int main(int argc, char* argv[]){
int option = 0;
double freq = 2e9;
double rate = 1e6;
double gain = 0;
char* device_args = NULL;
size_t channel = 0;
uint64_t total_num_samps = 0;
bool verbose = false;
int return_code = EXIT_SUCCESS;
char error_string[512];
// Process options
while((option = getopt(argc, argv, "a:f:r:g:n:vh")) != -1){
switch(option){
case 'a':
device_args = strdup(optarg);
break;
case 'f':
freq = atof(optarg);
break;
case 'r':
rate = atof(optarg);
break;
case 'g':
gain = atof(optarg);
break;
case 'n':
total_num_samps = atoll(optarg);
break;
case 'v':
verbose = true;
break;
case 'h':
print_help();
goto free_option_strings;
default:
print_help();
return_code = EXIT_FAILURE;
goto free_option_strings;
}
}
if(uhd_set_thread_priority(uhd_default_thread_priority, true)){
fprintf(stderr, "Unable to set thread priority. Continuing anyway.\n");
}
if (!device_args)
device_args = strdup("");
// Create USRP
uhd_usrp_handle usrp;
fprintf(stderr, "Creating USRP with args \"%s\"...\n", device_args);
EXECUTE_OR_GOTO(free_option_strings,
uhd_usrp_make(&usrp, device_args)
)
// Create TX streamer
uhd_tx_streamer_handle tx_streamer;
EXECUTE_OR_GOTO(free_usrp,
uhd_tx_streamer_make(&tx_streamer)
)
// Create TX metadata
uhd_tx_metadata_handle md;
EXECUTE_OR_GOTO(free_tx_streamer,
uhd_tx_metadata_make(&md, false, 0, 0.1, true, false)
)
// Create other necessary structs
uhd_tune_request_t tune_request = {
.target_freq = freq,
.rf_freq_policy = UHD_TUNE_REQUEST_POLICY_AUTO,
.dsp_freq_policy = UHD_TUNE_REQUEST_POLICY_AUTO
};
uhd_tune_result_t tune_result;
uhd_stream_args_t stream_args = {
.cpu_format = "fc32",
.otw_format = "sc16",
.args = "",
.channel_list = &channel,
.n_channels = 1
};
size_t samps_per_buff;
float* buff = NULL;
const void** buffs_ptr = NULL;
// Set rate
fprintf(stderr, "Setting TX Rate: %f...\n", rate);
EXECUTE_OR_GOTO(free_tx_metadata,
uhd_usrp_set_tx_rate(usrp, rate, channel)
)
// See what rate actually is
EXECUTE_OR_GOTO(free_tx_metadata,
uhd_usrp_get_tx_rate(usrp, channel, &rate)
)
fprintf(stderr, "Actual TX Rate: %f...\n\n", rate);
// Set gain
fprintf(stderr, "Setting TX Gain: %f db...\n", gain);
EXECUTE_OR_GOTO(free_tx_metadata,
uhd_usrp_set_tx_gain(usrp, gain, 0, "")
)
// See what gain actually is
EXECUTE_OR_GOTO(free_tx_metadata,
uhd_usrp_get_tx_gain(usrp, channel, "", &gain)
)
fprintf(stderr, "Actual TX Gain: %f...\n", gain);
// Set frequency
fprintf(stderr, "Setting TX frequency: %f MHz...\n", freq / 1e6);
EXECUTE_OR_GOTO(free_tx_metadata,
uhd_usrp_set_tx_freq(usrp, &tune_request, channel, &tune_result)
)
// See what frequency actually is
EXECUTE_OR_GOTO(free_tx_metadata,
uhd_usrp_get_tx_freq(usrp, channel, &freq)
)
fprintf(stderr, "Actual TX frequency: %f MHz...\n", freq / 1e6);
// Set up streamer
stream_args.channel_list = &channel;
EXECUTE_OR_GOTO(free_tx_streamer,
uhd_usrp_get_tx_stream(usrp, &stream_args, tx_streamer)
)
// Set up buffer
EXECUTE_OR_GOTO(free_tx_streamer,
uhd_tx_streamer_max_num_samps(tx_streamer, &samps_per_buff)
)
fprintf(stderr, "Buffer size in samples: %zu\n", samps_per_buff);
buff = calloc(sizeof(float), samps_per_buff * 2);
buffs_ptr = (const void**)&buff;
size_t i = 0;
for(i = 0; i < (samps_per_buff*2); i+=2){
buff[i] = 0.1f;
buff[i+1] = 0;
}
// Ctrl+C will exit loop
signal(SIGINT, &sigint_handler);
fprintf(stderr, "Press Ctrl+C to stop streaming...\n");
// Actual streaming
uint64_t num_acc_samps = 0;
size_t num_samps_sent = 0;
while(1) {
if (stop_signal_called) break;
if (total_num_samps > 0 && num_acc_samps >= total_num_samps) break;
EXECUTE_OR_GOTO(free_buff,
uhd_tx_streamer_send(tx_streamer, buffs_ptr, samps_per_buff, &md, 0.1, &num_samps_sent)
)
num_acc_samps += num_samps_sent;
if(verbose){
fprintf(stderr, "Sent %zu samples\n", num_samps_sent);
}
}
free_buff:
free(buff);
free_tx_streamer:
if(verbose){
fprintf(stderr, "Cleaning up TX streamer.\n");
}
uhd_tx_streamer_free(&tx_streamer);
free_tx_metadata:
if(verbose){
fprintf(stderr, "Cleaning up TX metadata.\n");
}
uhd_tx_metadata_free(&md);
free_usrp:
if(verbose){
fprintf(stderr, "Cleaning up USRP.\n");
}
if(return_code != EXIT_SUCCESS && usrp != NULL){
uhd_usrp_last_error(usrp, error_string, 512);
fprintf(stderr, "USRP reported the following error: %s\n", error_string);
}
uhd_usrp_free(&usrp);
free_option_strings:
if(device_args)
free(device_args);
fprintf(stderr, (return_code ? "Failure\n" : "Success\n"));
return return_code;
}
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