usrp_sink.h

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/* -*- c++ -*- */
/*
 * Copyright 2010-2016 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 */
 
#ifndef INCLUDED_GR_UHD_USRP_SINK_H
#define INCLUDED_GR_UHD_USRP_SINK_H
 
#include <gnuradio/uhd/usrp_block.h>
 
namespace gr {
namespace uhd {
 
class uhd_usrp_sink;
 
/*! USRP Sink -- Radio Transmitter
 * \ingroup uhd_blk
 *
 *
 * The USRP sink block reads a stream and transmits the samples.
 * The sink block also provides API calls for transmitter settings.
 * See also gr::uhd::usrp_block for more public API calls.
 *
 * \section uhd_tx_tagging TX Stream tagging
 *
 * The following tag keys will be consumed by the work function:
 *  - pmt::string_to_symbol("tx_sob")
 *  - pmt::string_to_symbol("tx_eob")
 *  - pmt::string_to_symbol("tx_time")
 *  - pmt::string_to_symbol("tx_freq")
 *  - pmt::string_to_symbol("tx_command")
 *  - pmt::string_to_symbol(tsb_tag_name)
 *
 * Any other tag will be ignored.
 *
 * \section uhd_tx_burstys Bursty Transmission
 *
 * There are multiple ways to do bursty transmission without triggering
 * underruns:
 * - Using SOB/EOB tags
 * - Using tagged streams (See <a
 * href="https://wiki.gnuradio.org/index.php/Tagged_Stream_Blocks" target="_blank">Tagged
 * Stream Blocks</a>)
 *
 * The sob and eob (start and end of burst) tag values are pmt booleans.
 * When present, burst tags should be set to true (pmt::PMT_T).
 *
 * If `tsb_tag_name` is not an empty string, all "tx_sob" and "tx_eob"
 * tags will be ignored, and the input is assumed to a tagged stream.
 *
 * If sob/eob tags or length tags are used, this block understands that
 * the data is bursty, and will configure the USRP to make sure there's
 * no underruns after transmitting the final sample of a burst.
 *
 * \section uhd_tx_time Timestamps
 *
 * The timestamp tag value is a PMT tuple of the following:
 * (uint64 seconds, double fractional seconds).
 *
 * The tx_freq tag has to be a double or a pair of form (channel, frequency),
 * with frequency being a double and channel being an integer.
 * This tag will trigger a tune command to the USRP
 * to the given frequency, if possible. Note that oscillators need some time
 * to stabilize after this! Don't expect clean data to be sent immediately after this
 * command. If channel is omitted, and only a double is given, it will set this frequency
 * to all channels.
 *
 * The command tag can carry a PMT command. See the following section.
 *
 * \section uhd_tx_commands Command interface
 *
 * There are two ways of passing commands to this block:
 * 1. tx_command tag. The command is attached to a sample, and will executed
 *    before the sample is transmitted, and after the previous sample.
 * 2. The 'command' message port. The command is executed asynchronously,
 *    as soon as possible.
 *
 * In both cases, the payload of the command is a PMT command, as described
 * in Section \ref uhd_command_syntax.
 *
 * For a more general description of the gr-uhd components, see \ref page_uhd.
 */
class GR_UHD_API usrp_sink : virtual public usrp_block
{
public:
    // gr::uhd::usrp_sink::sptr
    typedef std::shared_ptr<usrp_sink> sptr;
 
    /*!
     * \param device_addr the address to identify the hardware
     * \param stream_args the IO format and channel specification
     * \param tsb_tag_name the name of the tag identifying tagged stream length
     * \return a new USRP sink block object
     */
    static sptr make(const ::uhd::device_addr_t& device_addr,
                     const ::uhd::stream_args_t& stream_args,
                     const std::string& tsb_tag_name = "");
 
    // Also accept a string for the device_addr
    static sptr make(const std::string& device_addr_str,
                     const ::uhd::stream_args_t& stream_args,
                     const std::string& tsb_tag_name = "")
    {
        return make(::uhd::device_addr_t(device_addr_str), stream_args, tsb_tag_name);
    }
 
    /*!
     * Set the start time for outgoing samples.
     * To control when samples are transmitted,
     * set this value before starting the flow graph.
     * The value is cleared after each run.
     * When not specified, the start time will be:
     *  - Immediately for the one channel case
     *  - in the near future for multi-channel
     *
     * \param time the absolute time for transmission to begin
     */
    virtual void set_start_time(const ::uhd::time_spec_t& time) = 0;
 
    /*!
     * Get a list of possible LO stage names
     * \param chan the channel index 0 to N-1
     * \return a vector of strings for possible LO names
     */
    virtual std::vector<std::string> get_lo_names(size_t chan = 0) = 0;
 
    /*!
     * Set the LO source for the usrp device.
     * For usrps that support selectable LOs, this function
     * allows switching between them.
     * Typical options for source: internal, external.
     * \param src a string representing the LO source
     * \param name the name of the LO stage to update
     * \param chan the channel index 0 to N-1
     */
    virtual void
    set_lo_source(const std::string& src, const std::string& name, size_t chan = 0) = 0;
 
    /*!
     * Get the currently set LO source.
     * \param name the name of the LO stage to query
     * \param chan the channel index 0 to N-1
     * \return the configured LO source
     */
    virtual const std::string get_lo_source(const std::string& name, size_t chan = 0) = 0;
 
    /*!
     * Get a list of possible LO sources.
     * \param name the name of the LO stage to query
     * \param chan the channel index 0 to N-1
     * \return a vector of strings for possible settings
     */
    virtual std::vector<std::string> get_lo_sources(const std::string& name,
                                                    size_t chan = 0) = 0;
 
    /*!
     * Set whether the LO used by the usrp device is exported
     * For usrps that support exportable LOs, this function
     * configures if the LO used by chan is exported or not.
     * \param enabled if true then export the LO
     * \param name the name of the LO stage to update
     * \param chan the channel index 0 to N-1 for the source channel
     */
    virtual void
    set_lo_export_enabled(bool enabled, const std::string& name, size_t chan = 0) = 0;
 
    /*!
     * Returns true if the currently selected LO is being exported.
     * \param name the name of the LO stage to query
     * \param chan the channel index 0 to N-1
     */
    virtual bool get_lo_export_enabled(const std::string& name, size_t chan = 0) = 0;
 
    /*!
     * Set the RX LO frequency (Advanced).
     * \param freq the frequency to set the LO to
     * \param name the name of the LO stage to update
     * \param chan the channel index 0 to N-1
     * \return a coerced LO frequency
     */
    virtual double set_lo_freq(double freq, const std::string& name, size_t chan = 0) = 0;
 
    /*!
     * Get the current RX LO frequency (Advanced).
     * \param name the name of the LO stage to query
     * \param chan the channel index 0 to N-1
     * \return the configured LO frequency
     */
    virtual double get_lo_freq(const std::string& name, size_t chan = 0) = 0;
 
    /*!
     * Get the LO frequency range of the RX LO.
     * \param name the name of the LO stage to query
     * \param chan the channel index 0 to N-1
     * \return a frequency range object
     */
    virtual ::uhd::freq_range_t get_lo_freq_range(const std::string& name,
                                                  size_t chan = 0) = 0;
 
    /*!
     * Set a constant DC offset value.
     * The value is complex to control both I and Q.
     * \param offset the dc offset (1.0 is full-scale)
     * \param chan the channel index 0 to N-1
     */
    virtual void set_dc_offset(const std::complex<double>& offset, size_t chan = 0) = 0;
 
    /*!
     * Set the RX frontend IQ imbalance correction.
     * Use this to adjust the magnitude and phase of I and Q.
     *
     * \param correction the complex correction (1.0 is full-scale)
     * \param chan the channel index 0 to N-1
     */
    virtual void set_iq_balance(const std::complex<double>& correction,
                                size_t chan = 0) = 0;
};
 
} /* namespace uhd */
} /* namespace gr */
 
#endif /* INCLUDED_GR_UHD_USRP_SINK_H */