diff options
Diffstat (limited to 'host/python')
| -rw-r--r-- | host/python/uhd/usrp/multi_usrp.py | 87 |
1 files changed, 63 insertions, 24 deletions
diff --git a/host/python/uhd/usrp/multi_usrp.py b/host/python/uhd/usrp/multi_usrp.py index 7fb73c97e..a025b10d1 100644 --- a/host/python/uhd/usrp/multi_usrp.py +++ b/host/python/uhd/usrp/multi_usrp.py @@ -36,53 +36,92 @@ class MultiUSRP(lib.usrp.multi_usrp): self.get_tree().access_device_addr("/mboards/0/args").get().to_dict() setattr(self, 'get_mpm_client', lambda: _get_mpm_client(token, mb_args)) - def recv_num_samps(self, num_samps, freq, rate=1e6, channels=(0,), gain=10): + def recv_num_samps(self, + num_samps, + freq, + rate=1e6, + channels=(0,), + gain=10, + start_time=None, + streamer=None): """ RX a finite number of samples from the USRP + + This is a convenience function to minimize the amount of code required + for just capturing samples. When calling this function more than once + in a script, pass in a streamer object to avoid recreating streamers + more than once. + :param num_samps: number of samples to RX :param freq: RX frequency (Hz) :param rate: RX sample rate (Hz) :param channels: list of channels to RX on :param gain: RX gain (dB) + :param start_time: A valid TimeSpec object with the starting time. If + None, then streaming starts immediately. + :param streamer: An RX streamer object. If None, this function will create + one locally and attempt to destroy it afterwards. :return: numpy array of complex floating-point samples (fc32) """ - result = np.empty((len(channels), num_samps), dtype=np.complex64) - + def _config_streamer(streamer): + """ + Set up the correct streamer + """ + if streamer is None: + st_args = lib.usrp.stream_args("fc32", "sc16") + st_args.channels = channels + streamer = super(MultiUSRP, self).get_rx_stream(st_args) + return streamer + def _start_stream(streamer): + """ + Issue the start-stream command. + """ + stream_cmd = lib.types.stream_cmd(lib.types.stream_mode.start_cont) + stream_cmd.stream_now = (len(channels) == 1) and start_time is None + if not stream_cmd.stream_now: + if start_time is not None: + stream_cmd.time_spec = start_time + else: + stream_cmd.time_spec = lib.types.time_spec( + super(MultiUSRP, self).get_time_now().get_real_secs() + 0.05) + streamer.issue_stream_cmd(stream_cmd) + def _stop_stream(streamer): + """ + Issue the start-stream command and flush the queue. + """ + metadata = lib.types.rx_metadata() + stream_cmd = lib.types.stream_cmd(lib.types.stream_mode.stop_cont) + streamer.issue_stream_cmd(stream_cmd) + while streamer.recv(recv_buffer, metadata): + pass + ## And go! + # Configure USRP for chan in channels: super(MultiUSRP, self).set_rx_rate(rate, chan) super(MultiUSRP, self).set_rx_freq(lib.types.tune_request(freq), chan) super(MultiUSRP, self).set_rx_gain(gain, chan) - - st_args = lib.usrp.stream_args("fc32", "sc16") - st_args.channels = channels + # Configure streamer + streamer = _config_streamer(streamer) metadata = lib.types.rx_metadata() - streamer = super(MultiUSRP, self).get_rx_stream(st_args) - buffer_samps = streamer.get_max_num_samps() + # Set up buffers and counters + result = np.empty((len(channels), num_samps), dtype=np.complex64) recv_buffer = np.zeros( - (len(channels), buffer_samps), dtype=np.complex64) - + (len(channels), streamer.get_max_num_samps()), dtype=np.complex64) recv_samps = 0 - stream_cmd = lib.types.stream_cmd(lib.types.stream_mode.start_cont) - stream_cmd.stream_now = True - streamer.issue_stream_cmd(stream_cmd) - - samps = np.array([], dtype=np.complex64) + samps = 0 + # Now stream + _start_stream(streamer) while recv_samps < num_samps: samps = streamer.recv(recv_buffer, metadata) - if metadata.error_code != lib.types.rx_metadata_error_code.none: print(metadata.strerror()) if samps: real_samps = min(num_samps - recv_samps, samps) - result[:, recv_samps:recv_samps + real_samps] = recv_buffer[:, 0:real_samps] + result[:, recv_samps:recv_samps + real_samps] = \ + recv_buffer[:, 0:real_samps] recv_samps += real_samps - - stream_cmd = lib.types.stream_cmd(lib.types.stream_mode.stop_cont) - streamer.issue_stream_cmd(stream_cmd) - - while samps: - samps = streamer.recv(recv_buffer, metadata) - + # Stop and clean up + _stop_stream(streamer) # Help the garbage collection streamer = None return result |