FM Receiver, ATmega8
The purpose of ATMEGA8-16P1 based FM receiver project is to monitor polar orbiting weather satellites operated by the National Oceanographic and Atmospheric Administration (NOAA). The receiver will tune from 60 to 800 megahertz with an IF bandwidth of 50 kilohertz. While the IF bandwidth was chosen to be optimal for the NOAA polar orbiting weather satellites, it will receive narrow band FM, TV audio, and commercial FM stations.
The FM receiver consists of a: MCU; tuner; ceramic filter; second mixer; second oscillator; IF filter; audio integrated circuit; keypad; LCD; and power supply. The FM receiver detected a clear signal from a NOAA polar orbiting satellite when the satellite was 30 degrees above the horizon by using TV rabbit ears as an antenna. The receiver successfully picks up narrow band FM, TV audio, and commercial FM stations. However, commercial FM stations are distorted because the IF bandpass for this receiver is too narrow, yet they are still discernable.
The ATMEGA8-16P1 enabled the inclusion of a tuner with a built-in controller, which improved the speed of tuning, made the receiver more frequency stable, and allowed create user-friendly system by programming help screens. This FM receiver project was designed by Charles Schee and Karen Lynn Steelman from U.S.
AVR FM Receiver
Download Project Documentation (zip)
circuitcellar.com
