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add time recording and decoding

This commit is contained in:
King Kévin 2016-05-05 23:26:21 +02:00
parent 79bb509c83
commit 4493f34d22
2 changed files with 83 additions and 16 deletions
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95
lib/rtc_dcf77.c
View File

@ -23,8 +23,6 @@
#include <stdint.h> // standard integer types
#include <stdlib.h> // general utilities
#include <stdio.h>
/* STM32 (including CM3) libraries */
#include <libopencm3/stm32/rcc.h> // real-time control clock library
#include <libopencm3/stm32/gpio.h> // general purpose input output library
@ -37,6 +35,7 @@
#include "global.h" // common methods
volatile bool rtc_dcf77_time_flag = false;
volatile uint64_t rtc_dcf77_frame = 0; /**< the received DCF77 frame bits */
void rtc_dcf77_setup(void)
{
@ -72,36 +71,100 @@ void rtc_dcf77_off(void)
gpio_set(RTC_DCF77_ENABLE_PORT, RTC_DCF77_ENABLE_PIN); // disable module by pull pin high
}
uint8_t* rtc_dcf77_time(void)
{
static uint8_t to_return[6] = {0}; // arrays with date values to return
uint8_t parity = 0; // to check parity
if (rtc_dcf77_frame==0) { // no time received yet
return NULL;
}
if (!(rtc_dcf77_frame&(1<<20))) { // start of encode time should always be 1
return NULL;
}
// check minute parity
parity = 0;
for (uint8_t bit=21; bit<29; bit++) {
if (rtc_dcf77_frame&(1<<bit)) {
parity++; // count the set bits
}
}
if (parity%2) { // parity should be even
return NULL;
}
to_return[0] = 1*((rtc_dcf77_frame>>21)&(0x1))+2*((rtc_dcf77_frame>>22)&(0x1))+4*((rtc_dcf77_frame>>23)&(0x1))+8*((rtc_dcf77_frame>>24)&(0x1))+10*((rtc_dcf77_frame>>25)&(0x1))+20*((rtc_dcf77_frame>>26)&(0x1))+40*((rtc_dcf77_frame>>27)&(0x1)); // read minute (00-59)
// check hour parity
parity = 0;
for (uint8_t bit=29; bit<35; bit++) {
if (rtc_dcf77_frame&(1<<bit)) {
parity++; // count the set bits
}
}
if (parity%2) { // parity should be even
return NULL;
}
to_return[1] = 1*((rtc_dcf77_frame>>29)&(0x1))+2*((rtc_dcf77_frame>>30)&(0x1))+4*((rtc_dcf77_frame>>31)&(0x1))+8*((rtc_dcf77_frame>>32)&(0x1))+10*((rtc_dcf77_frame>>33)&(0x1))+20*((rtc_dcf77_frame>>34)&(0x1)); // read hour (00-23)
// check date parity
parity = 0;
for (uint8_t bit=36; bit<57; bit++) {
if (rtc_dcf77_frame&(1<<bit)) {
parity++; // count the set bits
}
}
if (parity%2) { // parity should be even
return NULL;
}
to_return[2] = 1*((rtc_dcf77_frame>>36)&(0x1))+2*((rtc_dcf77_frame>>37)&(0x1))+4*((rtc_dcf77_frame>>38)&(0x1))+8*((rtc_dcf77_frame>>39)&(0x1))+10*((rtc_dcf77_frame>>40)&(0x1))+20*((rtc_dcf77_frame>>34)&(0x41)); // read day of the month (01-31)
to_return[3] = 1*((rtc_dcf77_frame>>42)&(0x1))+2*((rtc_dcf77_frame>>43)&(0x1))+4*((rtc_dcf77_frame>>44)&(0x1)); // read day of the week (1=Monday - 7=Sunday)
to_return[4] = 1*((rtc_dcf77_frame>>45)&(0x1))+2*((rtc_dcf77_frame>>46)&(0x1))+4*((rtc_dcf77_frame>>47)&(0x1))+8*((rtc_dcf77_frame>>48)&(0x1))+10*((rtc_dcf77_frame>>49)&(0x1)); // read month of the year (01-12)
to_return[5] = 1*((rtc_dcf77_frame>>50)&(0x1))+2*((rtc_dcf77_frame>>51)&(0x1))+4*((rtc_dcf77_frame>>52)&(0x1))+8*((rtc_dcf77_frame>>53)&(0x1))+10*((rtc_dcf77_frame>>54)&(0x1))+20*((rtc_dcf77_frame>>55)&(0x1))+40*((rtc_dcf77_frame>>56)&(0x1))+80*((rtc_dcf77_frame>>57)&(0x1)); // read year of the century (00-99)
return to_return;
}
/** @brief interrupt service routine called when signal edge is detected */
void RTC_DCF77_SIGNAL_ISR(void)
{
exti_reset_request(RTC_DCF77_SIGNAL_EXTI); // reset interrupt
static uint16_t old_state = 0; // save last port state to detect difference
static uint8_t pulse = 0; // next pulse number in the DCF77 frame
//static uint16_t pulse_rising = 0, pulse_falling = 0; // time on when the last pulse edge has been detected
static uint16_t pulse_rising = 0;
static uint16_t pulse_edge = 0; // time on when the last pulse (rising edge) has been detected
static uint64_t rtc_dcf77_frame_tmp = 0; // the DCF77 frame bits as they get filled
uint16_t time = timer_get_counter(RTC_DCF77_TIMER); // get timer value
uint16_t new_state = gpio_get(RTC_DCF77_SIGNAL_PORT, RTC_DCF77_SIGNAL_PIN); // save last port state to detect difference
if (old_state!=new_state) { // pulse edge detected
time = (uint32_t)(time-pulse_edge)*RTC_DCF77_TIMER_MAX_TIME/(1<<16); // get time since last rising edge (integer underflow possible)
if (new_state) { // rising edge
time = (uint32_t)(time-pulse_rising)*RTC_DCF77_TIMER_MAX_TIME/(1<<16); // get time since last rising edge (integer underflow possible)
if (time < 900) { // ignore glitches
goto end;
} else if (time < 1100) { // a normal pulse
pulse = (pulse+1)%59; // go to next pulse (there should be no more than 59)
} else if (time < 1900) { // ignore glitch
goto end;
} else if (time < 2100) { // first pulse of a frame
if (time < 980) { // glitch
goto end; // ignore glitch
} else if (time < 1030) { // a normal pulse
pulse++; // go to next pulse
if (pulse>58) { // something wrong happened
pulse = 0; // restart
}
} else if (time < 1980) { // glitch
goto end; // ignore glitch
} else if (time < 2130) { // first pulse of a frame
if (pulse==58) { // full frame received
rtc_dcf77_frame = rtc_dcf77_frame_tmp; // save received complete frame
rtc_dcf77_time_flag = true; // notify user
}
pulse = 0;
} else { // something is wrong, restart
pulse = 0;
}
led_toggle();
pulse_rising = 0; // save new edge
pulse_edge = 0; // save new edge
timer_set_counter(RTC_DCF77_TIMER, 0); // reset timer to count
printf("%u\n", pulse);
}
} else { // falling edge
if (time < 90) { // glitch
goto end; // ignore glitch
} else if (time < 120) { // 0 received
rtc_dcf77_frame_tmp &= ~((uint64_t)1<<pulse); // save 0 bit
} else if (time < 190) { // glitch
goto end; // ignore glitch
} else if (time < 220) { // 1 received
rtc_dcf77_frame_tmp |= ((uint64_t)1<<pulse); // save 1 bit
}
}
}
end:
old_state = new_state; // save new state

4
lib/rtc_dcf77.h
View File

@ -51,3 +51,7 @@ void rtc_dcf77_setup(void);
void rtc_dcf77_on(void);
/** @brief switch off DCF77 time receiver module */
void rtc_dcf77_off(void);
/** @brief get last received DCF77 time
* @return array of {minutes (00-49), hours (00-23), date (01-31), day of the week (1-7=Monday-Sunday), month (01-12), year of the century (00-99)} if received time is valid, NULL else
*/
uint8_t* rtc_dcf77_time(void);