A communications adaptor comprises a receiver circuit, which can comprise a signal input configured to receive a frequency shift keyed (FSK) signal; a delay circuit in communication with the signal input and including a delayed signal output; a multiplier circuit in communication with the signal input and the delayed signal output, and the multiplier circuit can be configured to produce a serial bit steam from at least the signal input and the delayed signal output, the serial bit stream corresponds to one or more bits encoded with frequency shift keying in the FSK signal; and a signal output configured to output the serial bit stream. The communications adaptor also can comprise a transmitter circuit and a processor in communication with the receiver circuit and the transmitter circuit.