Electronic white cane Tom Pouce

Two types of sensors are implemented in Tom Thumb III: an infrared led sensor and a laser sensor. The laser detection is as fine as the laser beam, it is a triangulation laser rangefinder. The infrared detection has a wider field. The field of infrared detection is approximately a cylinder of revolution around the axis of the laser for a frontal detection.
Laser detection and infrared LED sensors work independently and are complementary. A simple logic function “OR” is used to merge the two feedbacks (if “obstacle” for one sensor and “no obstacle” for the other, we conclude “obstacle”).