From 2df2697107d7873232c31a25a6947711b0903edb Mon Sep 17 00:00:00 2001
From: Max Christian Pohle
Date: Mon, 27 Jul 2015 15:12:22 +0200
Subject: latest running version from march 2011, not having been in repo
 before, dcf77 working, mp3 playback and two display types are supported

---
 src/inc/int/dcf77/clock.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++
 src/inc/int/dcf77/clock.h |  98 +++++++++++++++++++++++++++++
 2 files changed, 255 insertions(+)
 create mode 100755 src/inc/int/dcf77/clock.c
 create mode 100755 src/inc/int/dcf77/clock.h

(limited to 'src/inc/int')

diff --git a/src/inc/int/dcf77/clock.c b/src/inc/int/dcf77/clock.c
new file mode 100755
index 0000000..75f33fe
--- /dev/null
+++ b/src/inc/int/dcf77/clock.c
@@ -0,0 +1,157 @@
+#include "clock.h"
+
+
+// returns -1 on error
+unsigned char getBits(const DCF start, const char len, const DCF pbit)
+{
+  static const unsigned char mult[]  = {1, 2, 4, 8, 10, 20 ,40 ,80};
+  /// unsigned char p = 1; //parity
+  unsigned char r = 0; // retval
+  unsigned char i;
+  for(i=0; i<len; i++)
+  {
+    r += dcf77[start+i].bit * mult[i];
+    /// if(dcf77[start+i].bit)
+      /// p ^= 1;
+  }
+
+  // 1110011
+  //  001000
+
+  // 8
+  // 72
+
+  /// if((pbit != DCF_FIRST) && (dcf77[pbit].bit != p))
+    /// return -1;
+  /// else
+    return r;
+}
+
+void set_dcf_value()
+{
+  // check for parity
+  /// if
+  /// (
+    /// (dcf77[DCF_FIRST].bit            != 0 ) |
+    /// (dcf77[DCF_START].bit            != 1 ) |
+    /// (getBits(DCF_MIN, 7, DCF_MINP)   == -1) |
+    /// (getBits(DCF_MIN, 7, DCF_START)   > 59) |
+    /// (getBits(DCF_HOUR, 6, DCF_HOURP) == -1)
+  /// ) return;
+
+  // set new time
+  t_current.m = (getBits(DCF_MIN,      7, DCF_START)) - 1;
+  t_current.h = (getBits(DCF_HOUR,     6, DCF_START));
+  t_current.dd = (getBits(DCF_DAY,     6, DCF_START));
+  t_current.wd = (getBits(DCF_WEEKDAY, 3, DCF_START));
+  t_current.mm = (getBits(DCF_MONTH,   5, DCF_START));
+  t_current.yy = (getBits(DCF_YEAR,    8, DCF_START));
+}
+
+//                                                       7372800/a=10000
+//                                                       115200 / a * x = 10000
+//                                                       7372800/8/150
+ISR(TIMER0_COMP_vect) // called 10000 times per second (12000000/8/150)
+{
+  //cli();
+  // F_CPU / PRESCALER / (OCR0 + 1)
+  if(++t_current.us >= 10) // one u-second
+  {
+    t_current.us = 0; // restart
+    // interval length of dcf77 can be greater than 1000 ms... count it!
+    ++interval;
+
+    /*
+    cli();
+    if(t_current.ms <= 500)
+    { OCR1A = 50 + (200 - (t_current.ms / 3)); }
+    else
+    { OCR1A = 50 + (200 - ((1000 - t_current.ms) / 3)); }
+    sei();
+    */
+
+    if(++t_current.ms >= 1000) // one second
+    {
+      t_current.ms = 0; // restart
+      if(++t_current.s > 59) // one minute
+      {
+        t_current.s = 0; // restart
+        if(++t_current.m > 59) // one hour
+        {
+          t_current.m = 0; // restart
+          if(++t_current.h > 23) // one day
+          {
+            t_current.h = 0; // restart
+            t_current.dd++;
+          }
+        }
+      }
+    }
+  }
+  //sei();
+}
+
+ISR(INT0_vect)
+{
+  /// stdout_put_int(interval, uart_putc);
+  /// stdout_put_string("INT0 call\n", uart_putc);
+  cli();
+  if(INT0_CONTROL == INT0_RISING_EDGE)
+  {
+    if(interval > 1000 && interval < 2000)  // 59th second - no rising edge at the beginning
+    {
+      /// if(dcf77_bit == 59) // check if every bit has been transfered
+      set_dcf_value();  // completely received- apply new time data
+
+      // 59th second: synchronize with receiver...
+      dcf77_bit    = 0;
+      TCNT0        = 0;
+      t_current.s  = 0;
+      t_current.ms = 0;
+      t_current.us = 0;
+    }
+    INT0_CONTROL = INT0_FALLING_EDGE;
+  }
+  else // INT0_FALLING_EDGE
+  {
+    dcf77[dcf77_bit++].bit = interval >= 200 ? 1 : 0;
+    lastinterval = interval;
+
+    INT0_CONTROL = INT0_RISING_EDGE;
+  }
+
+  interval = 0; // reset interval to count next interval
+  sei();
+}
+
+
+void timer_init()
+{
+  // 7372800/8
+  DDRD &= ~((1<<PD2) | (1<<PD3)); // make INT0 and INT1 input-pins
+
+  // Prescaler...
+  TCCR0  = (0<<CS02) | (1<<CS01) | (0<<CS00) | (1<<WGM01);
+  // output compare...
+  OCR0   = 149;
+  //OCR0   = 152 - 1;
+  //TCCR0 |= (0<<WGM01) | (1<<WGM01);
+
+  // ICNC1 (Input Capture Noise Canceler (4 CKs) Timer/Counter 1
+  // ICES1 (Input Capture Edge Select Timer/Counter 1) - 1:increasing 0:falling
+  // CSx: set prescaler (010 means 8)
+  /// TCCR1B = (1<<ICNC1) | (1<<ICES1) | (0<<CS12) | (1<<CS11) | (0<<CS10);
+  // OCIE0: Output Compare Match Interrupt Enable
+  // TICIE: Timer/Counter Input Capture Interrupt Enable
+  TIMSK |= (1<<OCIE0);
+
+  // interrupts_init...
+  // General Interrupt Mask Register (enables interrupts)
+  //GIMSK |= (1<<INT0);
+  GICR |= (1<<INT0);
+  // MCU Control Register (controls CPU-behaviours like interrupts & sleepmode)
+  //MCUCR |= (0<<ISC01) | (1<<ISC00); // any logical change generates interrupt
+  INT0_CONTROL = INT0_RISING_EDGE; // going to toggle int0-behaviour
+  /// loworhigh.bit = 0;
+}
+
diff --git a/src/inc/int/dcf77/clock.h b/src/inc/int/dcf77/clock.h
new file mode 100755
index 0000000..c7f75c7
--- /dev/null
+++ b/src/inc/int/dcf77/clock.h
@@ -0,0 +1,98 @@
+#ifndef CLOCK_H
+#define CLOCK_H
+  /* this dcf77-module relies on a accuarate clock (cristal) for receiving
+   * the dcf-signal. therefor the clock is going to work as expected,
+   * even with no dcf77-signal available.
+   * receivement is automatically turned on, if the avr is connected to the
+   * signal via INT0. if there is no signal the clock will not be set (K.I.S.S.)
+   *
+   */
+  #include <stdint.h>
+  #include <avr/io.h>
+  #include <avr/interrupt.h>
+  #include <limits.h>
+
+  /// #include "../stdout.h"
+  /// #include "../display/display.h"
+  /// #include "../uart/uart.h"
+
+  #define INT0_CONTROL       MCUCR
+  #define INT0_FALLING_EDGE  0x02
+  #define INT0_RISING_EDGE   0x03
+
+
+
+  typedef struct
+  {
+    volatile unsigned char bit : 1;
+  } Bit;
+
+  typedef struct
+  {
+    unsigned char h ;  // hour
+    unsigned char m ;  // minute
+    unsigned char s ;  // second
+    unsigned char dd;  // day
+    unsigned char wd;  // weekday
+    unsigned char mm;  // month
+    unsigned char yy;  // year
+    unsigned char us; // 10th second
+    unsigned int ms;  // milli second
+  } Time;
+
+  typedef enum
+  {
+    DCF_FIRST   = 0,  // start of a new minute (note: always 0)
+    DCF_WEATHER = 14, // proprietary :-(
+    DCF_ANTENNA = 15, // 0: normal, 1: replacement
+    DCF_DST     = 16, // daylight saving time: this hour new time...
+    DCF_MEZ     = 17, // 'summer-time'
+    DCF_MESZ    = 18, // 'winter-time'
+    DCF_DBLSEC  = 19, // one extra second gonna be inserted
+    DCF_START   = 20, // begin of time-info (note: always 1)
+    DCF_MIN     = 21, // 7 bit
+    DCF_MINP    = 28, // parity bit for minutes
+    DCF_HOUR    = 29, // 6 bit
+    DCF_HOURP   = 35, // parity bit for hours
+    DCF_DAY     = 36, // 6 bit
+    DCF_WEEKDAY = 42, // 3 bit
+    DCF_MONTH   = 45, // 5 bit
+    DCF_YEAR    = 50, // 8 bit
+    DCF_DATEP   = 58  // parity bit for date
+  } DCF;
+
+  /*
+  typedef struct
+  {
+    Bit useless[14];
+    Bit antenna;
+    Bit dst;
+    Bit mez;
+    Bit mesz;
+    Bit dblsec;
+    Bit start;               // < always 1 - use for verification
+    unsigned char min   : 7;
+    Bit min_p;               // < minutes parity
+    unsigned char hour  : 6;
+    Bit hour_p;              // < hours parity
+    unsigned char day   : 6; // day of month
+    unsigned char dow   : 3; // day of week (1=monday)
+    unsigned char month : 5; // month of year
+    unsigned char year  : 8; // year
+    Bit date_p;              // parity of date
+  } DCF_Signal;
+  */
+
+
+  volatile Bit dcf77[60];
+  volatile unsigned char dcf77_bit;
+  volatile Time t_current;
+  volatile unsigned int interval;
+  volatile unsigned int lastinterval;
+
+  /// void getBits(volatile unsigned char* target, const DCF start, const char len, const DCF parity);
+  /// void set_dcf_value();
+  void timer_init();
+  /// void interrupts_init();
+
+#endif
-- 
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