Retrieve Ping (HC-SR04 type) data. The data is presented as a
        dictionary.
        The 'key' is the trigger pin specified in sonar_config() and the
        'data' is the current measured distance (in centimeters)
        for that pin. If there is no data, the value is set to None.
        This is a FirmataPlus feature.

        :param trigger_pin: trigger pin specified in sonar_config

        :returns: active_sonar_map

def sonar_data_retrieve(self, trigger_pin):
        """
        Retrieve Ping (HC-SR04 type) data. The data is presented as a
        dictionary.
        The 'key' is the trigger pin specified in sonar_config() and the
        'data' is the current measured distance (in centimeters)
        for that pin. If there is no data, the value is set to None.
        This is a FirmataPlus feature.

        :param trigger_pin: trigger pin specified in sonar_config

        :returns: active_sonar_map
        """
        task = asyncio.ensure_future(self.core.sonar_data_retrieve(trigger_pin))
        sonar_data = self.loop.run_until_complete(task)
        return sonar_data