250cm / 99inch
250cm / 99inch
17
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Ultrasonic Sensor
The Ultrasonic Sensor is a digital sensor that can measure the
distance to an object in front of it. It does this by sending out high-
frequency sound waves and measuring how long it takes the sound
to reflect back to the sensor. The sound frequency is too high for
you to hear.
Distance to an object can be measured in either inches or
centimetres. This allows you to program your robot to stop a certain
distance from a wall.
When using centimetre units, the detectable distance is between 3
and 250 centimetres (with an accuracy of +/- 1 centimetres). When
using inch units, the measurable distance is between 1 and 99
inches (with an accuracy of +/- 0.394 inches). A value of 255
centimetres or 100 inches means the sensor is not able to detect
any object in front of it.
A steady light around the sensor eyes tells you that the sensor is in
Measure Mode. A blinking light tells you that it is in Presence Mode.
In Presence Mode, this sensor can detect another Ultrasonic Sensor
operating nearby. When listening for presence, the sensor detects
sound signals but does not send them.
The Ultrasonic Sensor can help your robots avoid furniture, track a
moving target, detect an intruder in your room, or ‘ping’ with
increasing volume or frequency as an object gets closer to the sensor.
For more information, see Using the Ultrasonic Sensor in the EV3
Software Help.
EV3 Sensors
Ultrasonic Sensor
Detectable distance
NOTE:
Since the Ultrasonic Sensor
depends on reflection of the sound
waves it may be ineffective at detecting
surfaces that are textured or objects that
are rounded. It is also possible for
an object to be too small for the
Ultrasonic Sensor to detect it.
EV3 TECHNOLOGY