create_obstacle_listener()

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Creates a listener triggered when an obstacle is found with the selected parameters (as in check_obstacle). The callback is called only once when the condition meets.

Reference

Arguments

Arguments	Type	Default value
listener_name	string		Unique listener identifier
callback	function or tuple		Callback (see the Callback section in the Listeners Schema page)
`lower_angle`	float		Lower bound of the angles range.
`upper_angle`	float		Upper bound of the angles range.
`lower_distance`	float	`0.0`	Lower bound of the distance range.
`upper_distance`	float	`float('inf')`	Upper bound of the distance range.
`ang_unit`	enum	`ANG_UNIT.DEG`	ENUM to select the unit of the angle: (`ANG_UNIT.DEG`) degrees or (`ANG_UNIT.RAD`) radians

Both lower_angle and upper_angle must be into the range [angle_min, angle_max] from laser info (see LidarController.get_laser_info())
upper_angle must be higher than lower_angle.
At least one of both lower_distance or upper_distance must be speficied.
upper_distance must be higher than lower_distance.

Return

None

Exceptions

Exception	Condition
`RayaLidarInvalidAngleUnit`
`RayaInvalidNumericRange`	upper_angle is lower than lower_angle or none of lower_distance and upper_distance are specified or upper_distance is lower than lower_distance.

See the complete list of Raya Exceptions.

Callback Arguments

Callback does not receive any arguments.

Examples

async def setup(self):
self.lidar.create_obstacle_listener(listener_name='obstacle',
                                              callback=self.callback_obstacle,
                                              lower_angle=260,
                                              upper_angle=280,
                                              upper_distance=2.0)
async def loop(self):
        await self.sleep(1.0)
        self.log.info('Doing other (non blocking) stuff!')

def callback_obstacle(self):
        self.log.warning('Obstacle!')
        
        
        
(INFO)<RayaApp.app.app> Doing other (non blocking) stuff!
(INFO)<RayaApp.app.app> Doing other (non blocking) stuff!
(WARNING)<RayaApp.app.app> Obstacle!
(INFO)<RayaApp.app.app> Doing other (non blocking) stuff!

TODO!

Go back to the Lidar Controller page.

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What's Next

delete_listener()

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Reference
Examples