async 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.

        :param trigger_pin: key into sonar data map

        :returns: active_sonar_map
        """
        # sonar_pin_entry = self.active_sonar_map[pin]
        sonar_pin_entry = self.active_sonar_map.get(trigger_pin)
        value = sonar_pin_entry[1]
        return value
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.

        :param trigger_pin: key into sonar data map

        :returns: active_sonar_map