Grove – 80cm Infrared Proximity Sensor

• Grove interface compatible
• Wide supply voltage range: 2.5V–7V

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Interface

This sensor is quite small and use a tiny connector called the Japan Solderless Terminal (JST) connector. These connectors have three wires: ground, vcc, and the output. Because the sensor fire continuously and don’t need any clocking to initiate a reading, it is easy to interface with any microcontroller. for the seeeduino, the wire convert the 3-wire to 4-wire ,to compatible with the twig interface of Grove .

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Theory of Operation

This new rangers use triangulation and a small linear CCD array to compute the distance and/or presence of objects in the field of view. The basic idea is this: a pulse of IR light is emitted by the emitter. This light travels out in the field of view and either hits an object or just keeps on going. In the case of no object, the light is never reflected and the reading shows no object. If the light reflects off an object, it returns to the detector and creates a triangle between the point of reflection, the emitter, and the detector.

The angles in this triangle vary based on the distance to the object. The receiver portion of these new detectors is actually a precision lens that transmits the reflected light onto various portions of the enclosed linear CCD array based on the angle of the triangle described above. The CCD array can then determine what angle the reflected light came back at and therefore, it can calculate the distance to the object.

This new method of ranging is almost immune to interference from ambient light and offers amazing indifference to the color of object being detected. Detecting a black wall in full sunlight is now possible.