The Sharp sensor type GP2YA21YK is widely used low priced economical distance sensor. This sensor is mainly used for automatic towel dispensers and toilet flushing. . This sensor is however is highly sensitive to electromagnetic interference (EMI).
One of our customers intended to use this sensor in a robotic environment with heavy electrical engines and other power consumers. High EMI sensitivity caused frequent malfunctions. First solution were sought through external shielding. No adequate result was achieved. Finally we choose to redesign the print and reuse only the IR component from the SHARP sensor. The enhanced print has additional filters and multilayer internal shielding. The sensitivity to EMI is reduced to practically zero and the sensor generates a more stable signal.