Difference between revisions of "Getting Started with UHD and C++"
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==Creating a USRP Object== | ==Creating a USRP Object== | ||
+ | Make a new multi usrp from the device address. | ||
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<syntaxhighlight lang="c++"> | <syntaxhighlight lang="c++"> | ||
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uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(device_args); | uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(device_args); | ||
</syntaxhighlight> | </syntaxhighlight> |
Revision as of 14:45, 15 May 2016
Contents
- 1 Application Note Number
- 2 Revision History
- 3 Abstract
- 4 Overview
- 5 UHD Manual
- 6 Including Header Files
- 7 UHD_SAFE_MAIN()
- 8 set_thread_priority_safe()
- 9 Create Variables
- 10 Creating a USRP Object
- 11 Setting Motherboard Clocks
- 12 Selecting Sub Device
- 13 Setting Sample Rate
- 14 Setting Center Frequency
- 15 Setting RF Gain
- 16 Setting IF Filter Bandwidth
- 17 Selecting Antenna
- 18 Exiting
- 19 Full Example
- 20 CMake
- 21 Compile and Install
- 22 Running the Application
- 23 Additional Example Programs
Application Note Number
AN-204
Revision History
Date | Author | Details |
---|---|---|
2016-05-01 | Neel Pandeya Nate Temple |
Initial creation |
Abstract
This AN explains how to write and build C++ programs that use the UHD API.
Overview
This Application Note will walk through building a basic C++ program with UHD. This program will initialize, configure the USRP device, set the sample rate, frequency, gain, bandwidth, and select the antenna.
UHD Manual
The UHD Manual is hosted at http://files.ettus.com/manual/index.html and provides information on how to use the USRP devices and how to use the UHD API to connect to them through your own software. The manual is split into two parts: The device manual, and the UHD/API manual. The first part describes details of Ettus Research devices, motherboards and daughterboards, as well as aspects of using UHD. The second is meant for developers writing UHD-based applications, and includes descriptions of the API, sorted by namespaces, classes, and files.
Including Header Files
#include <uhd/utils/thread_priority.hpp>
#include <uhd/utils/safe_main.hpp>
#include <uhd/usrp/multi_usrp.hpp>
#include <uhd/exception.hpp>
#include <uhd/types/tune_request.hpp>
#include <boost/program_options.hpp>
#include <boost/format.hpp>
#include <boost/thread.hpp>
#include <iostream>
UHD_SAFE_MAIN()
Defines a safe wrapper that places a catch-all around main. If an exception is thrown, it prints to stderr and returns.
int UHD_SAFE_MAIN(int argc, char *argv[]) {
...
}
set_thread_priority_safe()
Set the scheduling priority on the current thread. Same as set_thread_priority but does not throw on failure.
uhd::set_thread_priority_safe();
Create Variables
std::string device_args("addr=192.168.10.2");
std::string subdev("A:0");
std::string ant("TX/RX");
std::string ref("internal");
double rate(1e6);
double freq(915e6);
double gain(10);
double bw(1e6);
Creating a USRP Object
Make a new multi usrp from the device address.
uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(device_args);
Setting Motherboard Clocks
// Lock mboard clocks
std::cout << boost::format("Lock mboard clocks: %f") % ref << std::endl;
usrp->set_clock_source(ref);
Selecting Sub Device
//always select the subdevice first, the channel mapping affects the other settings
std::cout << boost::format("subdev set to: %f") % subdev << std::endl;
usrp->set_rx_subdev_spec(subdev);
std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
Setting Sample Rate
//set the sample rate
if (rate <= 0.0) {
std::cerr << "Please specify a valid sample rate" << std::endl;
return ~0;
}
// set sample rate
std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate / 1e6) << std::endl;
usrp->set_rx_rate(rate);
std::cout << boost::format("Actual RX Rate: %f Msps...") % (usrp->get_rx_rate() / 1e6) << std::endl << std::endl;
Setting Center Frequency
// set freq
std::cout << boost::format("Setting RX Freq: %f MHz...") % (freq / 1e6) << std::endl;
uhd::tune_request_t tune_request(freq);
usrp->set_rx_freq(tune_request);
std::cout << boost::format("Actual RX Freq: %f MHz...") % (usrp->get_rx_freq() / 1e6) << std::endl << std::endl;
Setting RF Gain
// set the rf gain
std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
usrp->set_rx_gain(gain);
std::cout << boost::format("Actual RX Gain: %f dB...") % usrp->get_rx_gain() << std::endl << std::endl;
Setting IF Filter Bandwidth
// set the IF filter bandwidth
std::cout << boost::format("Setting RX Bandwidth: %f MHz...") % (bw / 1e6) << std::endl;
usrp->set_rx_bandwidth(bw);
std::cout << boost::format("Actual RX Bandwidth: %f MHz...") % (usrp->get_rx_bandwidth() / 1e6) << std::endl << std::endl;
Selecting Antenna
std::cout << boost::format("Setting RX Antenna: %s") % ant << std::endl;
usrp->set_rx_antenna(ant);
std::cout << boost::format("Actual RX Antenna: %s") % usrp->get_rx_antenna() << std::endl << std::endl;
Exiting
return EXIT_SUCCESS;
Full Example
#include <uhd/utils/thread_priority.hpp>
#include <uhd/utils/safe_main.hpp>
#include <uhd/usrp/multi_usrp.hpp>
#include <uhd/exception.hpp>
#include <uhd/types/tune_request.hpp>
#include <boost/program_options.hpp>
#include <boost/format.hpp>
#include <boost/thread.hpp>
#include <iostream>
int UHD_SAFE_MAIN(int argc, char *argv[]) {
uhd::set_thread_priority_safe();
std::string device_args("addr=192.168.10.2");
std::string subdev("A:0");
std::string ant("TX/RX");
std::string ref("internal");
double rate(1e6);
double freq(915e6);
double gain(10);
double bw(1e6);
//create a usrp device
std::cout << std::endl;
std::cout << boost::format("Creating the usrp device with: %s...") % device_args << std::endl;
uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(device_args);
// Lock mboard clocks
std::cout << boost::format("Lock mboard clocks: %f") % ref << std::endl;
usrp->set_clock_source(ref);
//always select the subdevice first, the channel mapping affects the other settings
std::cout << boost::format("subdev set to: %f") % subdev << std::endl;
usrp->set_rx_subdev_spec(subdev);
std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
//set the sample rate
if (rate <= 0.0) {
std::cerr << "Please specify a valid sample rate" << std::endl;
return ~0;
}
// set sample rate
std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate / 1e6) << std::endl;
usrp->set_rx_rate(rate);
std::cout << boost::format("Actual RX Rate: %f Msps...") % (usrp->get_rx_rate() / 1e6) << std::endl << std::endl;
// set freq
std::cout << boost::format("Setting RX Freq: %f MHz...") % (freq / 1e6) << std::endl;
uhd::tune_request_t tune_request(freq);
usrp->set_rx_freq(tune_request);
std::cout << boost::format("Actual RX Freq: %f MHz...") % (usrp->get_rx_freq() / 1e6) << std::endl << std::endl;
// set the rf gain
std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
usrp->set_rx_gain(gain);
std::cout << boost::format("Actual RX Gain: %f dB...") % usrp->get_rx_gain() << std::endl << std::endl;
// set the IF filter bandwidth
std::cout << boost::format("Setting RX Bandwidth: %f MHz...") % (bw / 1e6) << std::endl;
usrp->set_rx_bandwidth(bw);
std::cout << boost::format("Actual RX Bandwidth: %f MHz...") % (usrp->get_rx_bandwidth() / 1e6) << std::endl << std::endl;
// set the antenna
std::cout << boost::format("Setting RX Antenna: %s") % ant << std::endl;
usrp->set_rx_antenna(ant);
std::cout << boost::format("Actual RX Antenna: %s") % usrp->get_rx_antenna() << std::endl << std::endl;
return EXIT_SUCCESS;
}
CMake
Use the uhd/host/examples/init_usrp/CMakeLists.txt file as template - Add the names of your C++ source files to the add_executable(...) section - Put both modified CMakeLists.txt file and C++ file into an empty folder
Compile and Install
- Create a “build” folder and invoke CMake the usual way:
mkdir build cd build cmake ../ make
Running the Application
[example output]
Additional Example Programs
- Github UHD