Micro-controller based frequency calibration

A receiver for processing a carrier frequency signal modulated with data from an antenna, the receiver comprising:

• 1) a mixer in electrical communication with the antenna for mixing the received carrier frequency signal with an initial oscillator signal to thereby generate an intermediate frequency signal;
• 2) a FM discriminator in electrical communication with the mixer to demodulate the intermediate frequency signal and to generate a DC offset voltage level responsive to the carrier frequency of the received signal;
• 3) a received signal strength indicator in electrical communication with the mixer, the strength indicator being operative to generate a microprocessor control signal only when the power of the intermediate frequency signal is above a preset threshold;
• 4) a microprocessor.sub.13 in electrical communication with the FM discriminator and the received signal strength indicator, the microprocessor being operative to generate an error signal responsive to the difference between the discriminator DC offset voltage level and a preset DC offset voltage level in response to the microprocessor control signal such that only error signal generation is terminated when the power of the intermediate frequency signal is below a preset threshold;
• and
• 5) an oscillator in electrical communication with the mixer and the error signal, the oscillator being operative to adjust the frequency of the initial oscillator signal in response to the error signal to thereby generate a successive oscillator signal applied to the mixer and frequency matched to the carrier frequency of the received signal such that the receiver is operative to continuously receive signals.