Abstract: A device for controlling an accessory based on the detection of transmissions of appropriate input frequency exceeding a minimum threshold amplitude from a nearby cellular telephone. The device includes an independent receiver for directly detecting the transmissions from the nearby cellular telephone and a controller connected to the receiver for controlling the accessory device based on the detection of the transmission from the nearby cellular phone. The independent receiver includes a frequency discriminator of a totally digital design for detecting a signal which is greater than a predetermined threshold frequency and amplitude.