DCF77 Files

DCF77.c, DCF77.h are a platform independent DCF77 signal processing for micros written in c.

It only needs a periodic call of 10ms interval passing the signal status of a digital input from the receiver hardware. One can call it by a periodic ISR, a Round Robin algorithm or a timer callback.

There is also a polling function that returns the RTC clock data by a data structure. The clock continues to run also if there is no DCF signal. The exact data and functions is found in the header file dcf77.h.  

An example code with the Raspberry Pi Pico is found in dcf_main.c. It uses a preiodic timer callback to set a flag for the main round robin task. The periodic call can be also called directly in the timer callback or also from an interrupt service routine (ISR).

The only platform dependent restriction may be is that it uses 64-bit integers for the raw data (uint64_t). This is because the DCF77 transmitter sends 60 bits in a row every minute. When using an 8051 derivate with a Keil Compiler for example, this might not work without some tweaks.

Exact technical domumentation is found on:
https://en.wikipedia.org/wiki/DCF77