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Display Speck 2c mini dvs
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An example that uses a :code:`speck2cMiniTestBoard` to display DVS events of Speck 2c mini model in visualizer.

This example based on packages :

::

    - samna                 0.30.9

Structure:

.. image:: ../../../../images/display_speck2cMini_dvs.png
    :alt: Speck 2c mini dvs display data flow structure
    :align: center
    :width: 100%

.. code-block:: python

    from multiprocessing import Process

    import samna
    import samnagui


    def open_speck2c_mini():
        return samna.device.open_device("Speck2cMiniTestBoard:0")


    def build_samna_event_route(dk, dvs_graph, streamer_endpoint):
        # build a graph in samna to show dvs
        _, _, streamer = dvs_graph.sequential(
            [dk.get_model_source_node(), "Speck2cMiniDvsToVizConverter", "VizEventStreamer"]
        )

        config_source, _ = dvs_graph.sequential(
            [samna.BasicSourceNode_ui_event(), streamer]
        )

        streamer.set_streamer_endpoint(streamer_endpoint)
        if streamer.wait_for_receiver_count() == 0:
            raise Exception(f"connecting to visualizer on {streamer_endpoint} fails")

        return config_source


    def open_visualizer(window_width, window_height, receiver_endpoint):
        # start visualizer in a isolated process which is required on mac, intead of a sub process.
        gui_process = Process(
            target=samnagui.run_visualizer,
            args=(receiver_endpoint, window_width, window_height),
        )
        gui_process.start()

        return gui_process


    streamer_endpoint = "tcp://0.0.0.0:40000"

    gui_process = open_visualizer(0.75, 0.75, streamer_endpoint)

    dk = open_speck2c_mini()

    stopWatch = dk.get_stop_watch()
    stopWatch.set_enable_value(True)  # open timestamp

    # route events
    dvs_graph = samna.graph.EventFilterGraph()
    config_source = build_samna_event_route(dk, dvs_graph, streamer_endpoint)

    dvs_graph.start()

    config_source.write(
        [
            samna.ui.VisualizerConfiguration(
                plots=[samna.ui.ActivityPlotConfiguration(128, 128, "DVS Layer")]
            )
        ]
    )

    # modify configuration
    config = samna.speck2cMini.configuration.SpeckConfiguration()
    # have to set these three to true in order to visualize the dvs events
    config.factory_config.p2s_monitor_enable = True
    config.factory_config.p2s_readout_output_enable = False
    config.dvs_layer.monitor_enable = True
    dk.get_model().apply_configuration(config)

    # wait until visualizer window destroys.
    gui_process.join()

    dvs_graph.stop()