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AVR single chip controllers AT90S, ATtiny, ATmega and ATxmega
DCF77 receiver controller with LCD and RS232 with an ATmega324
This project is experimental. I don't know if it really works as planned here.

10 DCF77 AM receivers

10.9 DCF77 receiver controller with LCD and RS232 with ATmega324

OpAmp-Receiver For the regulated DCF77 direct receiver with two operational amplifiers you can also use this controller. It works without a serial interface (like the concept with the ATtiny25) and has all components on board to display time and date as well as status info on an LCD. It
  1. measures the amplitude of the DCF77 receiver, and
  2. regulates the frequency of DCF77 input stage with an AFC voltage, and
  3. regulates the gain of the two operational amplifiers with a negative AGC voltage, and
  4. displays date, time and status on an LCD, and
  5. can be adjusted even without DCF77 with three keys, by which date and time can be changed manually, and
  6. has an on-board crystal oscillator that can handle time and date even without DCF77 synchronization with the necessary accuracy, and
  7. can be used as alarm clock by setting an alarm time, at which diverse melodies wake you up, and
  8. transmits date and time via a two-way RS232 connection and receives commands via the RS232 interface.
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10.9.1 Hardware

Schematic of the ATmega324 controller for DCF77 This is the complete schematic of the controller. It has all that is needed for all the above features.

RS232 interface for the controller With this addition the controller can communicate with a PC or laptop via a two-way RS232 interface. The date and time can be manually adjusted via a terminal program.

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10.9.2 Software

The Software is still under construction.

10.9.3 Documentation

All drawings are in the Libre-Office-Draw file here. Calculations are in the Libre-Office-Calc file here.

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