python: multi_usrp: Fix issues in send_waveform()

- Like with RX, this now allows passing in stream time and existing
  streamer
- There was no EOB being sent at the end (now there is)
- Fixed some linter issues

1 files changed, 29 insertions, 12 deletions

diff --git a/host/python/uhd/usrp/multi_usrp.py b/host/python/uhd/usrp/multi_usrp.py
index a025b10d1..f9aa1a857 100644
--- a/host/python/uhd/usrp/multi_usrp.py
+++ b/host/python/uhd/usrp/multi_usrp.py
@@ -87,7 +87,7 @@ class MultiUSRP(lib.usrp.multi_usrp):
             streamer.issue_stream_cmd(stream_cmd)
         def _stop_stream(streamer):
             """
-            Issue the start-stream command and flush the queue.
+            Issue the stop-stream command and flush the queue.
             """
             metadata = lib.types.rx_metadata()
             stream_cmd = lib.types.stream_cmd(lib.types.stream_mode.stop_cont)
@@ -132,7 +132,9 @@ class MultiUSRP(lib.usrp.multi_usrp):
                       freq,
                       rate=1e6,
                       channels=(0,),
-                      gain=10):
+                      gain=10,
+                      start_time=None,
+                      streamer=None):
         """
         TX a finite number of samples from the USRP
         :param waveform_proto: numpy array of samples to TX
@@ -141,42 +143,57 @@ class MultiUSRP(lib.usrp.multi_usrp):
         :param rate: TX sample rate (Hz)
         :param channels: list of channels to TX on
         :param gain: TX gain (dB)
+        :param start_time: A valid TimeSpec object with the starting time. If
+                           None, then streaming starts immediately.
+        :param streamer: A TX streamer object. If None, this function will create
+                         one locally and attempt to destroy it afterwards.
         :return: the number of transmitted samples
         """
+        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_tx_stream(st_args)
+            return streamer
+        ## And go!
         for chan in channels:
             super(MultiUSRP, self).set_tx_rate(rate, chan)
             super(MultiUSRP, self).set_tx_freq(lib.types.tune_request(freq), chan)
             super(MultiUSRP, self).set_tx_gain(gain, chan)
 
-        st_args = lib.usrp.stream_args("fc32", "sc16")
-        st_args.channels = channels
-
-        streamer = super(MultiUSRP, self).get_tx_stream(st_args)
+        # Configure streamer
+        streamer = _config_streamer(streamer)
+        # Set up buffers and counters
         buffer_samps = streamer.get_max_num_samps()
         proto_len = waveform_proto.shape[-1]
-
         if proto_len < buffer_samps:
             waveform_proto = np.tile(waveform_proto,
                                      (1, int(np.ceil(float(buffer_samps)/proto_len))))
             proto_len = waveform_proto.shape[-1]
-
-        metadata = lib.types.tx_metadata()
         send_samps = 0
         max_samps = int(np.floor(duration * rate))
-
         if len(waveform_proto.shape) == 1:
             waveform_proto = waveform_proto.reshape(1, waveform_proto.size)
         if waveform_proto.shape[0] < len(channels):
             waveform_proto = np.tile(waveform_proto[0], (len(channels), 1))
-
+        # Now stream
+        metadata = lib.types.tx_metadata()
+        if start_time is not None:
+            metadata.time_spec = start_time
         while send_samps < max_samps:
             real_samps = min(proto_len, max_samps-send_samps)
             if real_samps < proto_len:
+                print(waveform_proto[:, :real_samps])
                 samples = streamer.send(waveform_proto[:, :real_samps], metadata)
             else:
                 samples = streamer.send(waveform_proto, metadata)
             send_samps += samples
-
+        # Send EOB to terminate Tx
+        metadata.end_of_burst = True
+        streamer.send(np.zeros((len(channels), 1), dtype=np.complex64), metadata)
         # Help the garbage collection
         streamer = None
         return send_samps