DigitalInfinity/ESP32-PaxCounter
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DCF77 optimizations

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This commit is contained in:
Klaus K Wilting 2019-02-07 20:39:32 +01:00
parent f5e5bf798a
commit e1b6d9a04c
3 changed files with 120 additions and 99 deletions
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1
include/dcf77.h
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@ -17,5 +17,6 @@ void DCF_Out(uint8_t startsec);
void generateTimeframe(time_t t);
void set_DCF77_pin(dcf_pinstate state);
uint8_t dec2bcd(uint8_t dec, uint8_t startpos, uint8_t endpos, uint8_t pArray[]);
uint8_t sync_clock(time_t t);
#endif

215
src/dcf77.cpp
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@ -44,8 +44,7 @@ int dcf77_init(void) {
assert(DCF77Task); // has dcf77 task started?
// if we have hardware pps signal we use it as precise time base
#ifdef RTC_INT
#ifdef RTC_INT // if we have hardware pps signal we use it as precise time base
#ifndef RTC_CLK // assure we know external clock freq
#error "External clock cycle not defined in board hal file"
@ -65,24 +64,20 @@ int dcf77_init(void) {
return 0; // failure
}
// if we don't have pps signal from RTC we emulate it using ESP32 hardware timer
#else
#else // if we don't have pps signal from RTC we use ESP32 hardware timer
#define RTC_CLK (DCF77_PULSE_DURATION) // setup clock cycle
ESP_LOGI(TAG, "Time base ESP32 clock");
dcfCycle = timerBegin(1, 8000, true); // set 80 MHz prescaler to 1/10000 sec
timerAttachInterrupt(dcfCycle, &DCF77IRQ, true);
timerAlarmWrite(dcfCycle, 10 * RTC_CLK, true); // RTC_CLK / 1sec = 100ms
timerAlarmWrite(dcfCycle, 10 * RTC_CLK, true); // 100ms
#endif
// wait until beginning of next second, then kick off first DCF pulse and
// start clock signal
t = tt = now();
do {
tt = now();
} while (t == tt);
DCF_Out(second(tt));
DCF_Out(sync_clock(now()));
#ifdef RTC_INT // start external clock
attachInterrupt(digitalPinToInterrupt(RTC_INT), DCF77IRQ, FALLING);
@ -93,6 +88,103 @@ int dcf77_init(void) {
return 1; // success
} // ifdcf77_init
// called every 100msec by hardware timer to pulse out DCF signal
void DCF_Out(uint8_t startOffset) {
static uint8_t bit = startOffset;
static uint8_t pulse = 0;
#ifdef TIME_SYNC_INTERVAL_DCF
static uint32_t nextDCFsync = millis() + TIME_SYNC_INTERVAL_DCF * 60000;
#endif
if (!BitsPending) {
// prepare frame to send for next minute
generateTimeframe(now() + DCF77_FRAME_SIZE + 1);
// start blinking symbol on display and kick off timer
BitsPending = true;
}
// ticker out current DCF frame
if (BitsPending) {
switch (pulse++) {
case 0: // start of second -> start of timeframe for logic signal
if (DCFtimeframe[bit] != dcf_off)
set_DCF77_pin(dcf_low);
break;
case 1: // 100ms after start of second -> end of timeframe for logic 0
if (DCFtimeframe[bit] == dcf_zero)
set_DCF77_pin(dcf_high);
break;
case 2: // 200ms after start of second -> end of timeframe for logic 1
set_DCF77_pin(dcf_high);
break;
case 9: // 900ms after start -> last pulse before next second starts
pulse = 0;
if (bit++ == (DCF77_FRAME_SIZE - 1)) // end of DCF77 frame (59th second)
{
bit = 0;
BitsPending = false;
// recalibrate clock after a fixed timespan, do this in 59th second
#ifdef TIME_SYNC_INTERVAL_DCF
if ((millis() >= nextDCFsync)) {
sync_clock(now()); // in second 58,90x -> waiting for second 59
nextDCFsync = millis() + TIME_SYNC_INTERVAL_DCF *
60000; // set up next time sync period
}
#endif
};
break;
}; // switch
}; // if
} // DCF_Out()
void dcf77_loop(void *pvParameters) {
configASSERT(((uint32_t)pvParameters) == 1); // FreeRTOS check
TickType_t wakeTime;
// task remains in blocked state until it is notified by isr
for (;;) {
xTaskNotifyWait(
0x00, // don't clear any bits on entry
ULONG_MAX, // clear all bits on exit
&wakeTime, // receives moment of call from isr
portMAX_DELAY); // wait forever (missing error handling here...)
#if (RTC_CLK == DCF77_PULSE_DURATION)
DCF_Out(0); // we don't need clock rescaling
#else // we need clock rescaling by software timer
for (uint8_t i = 1; i <= RTC_CLK / DCF77_PULSE_DURATION; i++) {
DCF_Out(0);
vTaskDelayUntil(&wakeTime, pdMS_TO_TICKS(DCF77_PULSE_DURATION));
}
#endif
} // for
} // dcf77_loop()
// helper function to convert decimal to bcd digit
uint8_t dec2bcd(uint8_t dec, uint8_t startpos, uint8_t endpos,
uint8_t pArray[]) {
uint8_t data = (dec < 10) ? dec : ((dec / 10) << 4) + (dec % 10);
uint8_t parity = 0;
for (uint8_t n = startpos; n <= endpos; n++) {
pArray[n] = (data & 1) ? dcf_one : dcf_zero;
parity += (data & 1);
data >>= 1;
}
return parity;
}
void generateTimeframe(time_t tt) {
uint8_t ParityCount;
@ -141,93 +233,6 @@ void generateTimeframe(time_t tt) {
*/
}
// called every 100msec by hardware timer to pulse out DCF signal
void DCF_Out(uint8_t startOffset) {
static uint8_t bit = startOffset;
static uint8_t pulse = 0;
if (!BitsPending) {
// prepare frame to send for next minute
generateTimeframe(now() + 61);
// start blinking symbol on display and kick off timer
BitsPending = true;
}
// ticker out current DCF frame
if (BitsPending) {
switch (pulse++) {
case 0: // start of second -> start of timeframe for logic signal
if (DCFtimeframe[bit] != dcf_off)
set_DCF77_pin(dcf_low);
break;
case 1: // 100ms after start of second -> end of timeframe for logic 0
if (DCFtimeframe[bit] == dcf_zero)
set_DCF77_pin(dcf_high);
break;
case 2: // 200ms after start of second -> end of timeframe for logic 1
set_DCF77_pin(dcf_high);
break;
case 9: // 900ms after start -> last pulse before next second starts
pulse = 0;
if (bit++ == (DCF77_FRAME_SIZE - 1)) // end of DCF77 frame (59th second)
{
bit = 0;
BitsPending = false;
};
break;
}; // switch
}; // if
} // DCF_Out()
void dcf77_loop(void *pvParameters) {
configASSERT(((uint32_t)pvParameters) == 1); // FreeRTOS check
TickType_t wakeTime;
// task remains in blocked state until it is notified by isr
for (;;) {
xTaskNotifyWait(
0x00, // don't clear any bits on entry
ULONG_MAX, // clear all bits on exit
&wakeTime, // receives moment of call from isr
portMAX_DELAY); // wait forever (missing error handling here...)
#if (!defined RTC_INT) || (RTC_CLK == DCF77_PULSE_DURATION)
DCF_Out(0); // we don't need clock rescaling
#else // we need clock rescaling by software timer
for (uint8_t i = 1; i <= RTC_CLK / DCF77_PULSE_DURATION; i++) {
DCF_Out(0);
vTaskDelayUntil(&wakeTime, pdMS_TO_TICKS(DCF77_PULSE_DURATION));
} // for
#endif
} // for
} // dcf77_loop()
// helper function to convert decimal to bcd digit
uint8_t dec2bcd(uint8_t dec, uint8_t startpos, uint8_t endpos,
uint8_t pArray[]) {
uint8_t data = (dec < 10) ? dec : ((dec / 10) << 4) + (dec % 10);
uint8_t parity = 0;
for (uint8_t n = startpos; n <= endpos; n++) {
pArray[n] = (data & 1) ? dcf_one : dcf_zero;
parity += (data & 1);
data >>= 1;
}
return parity;
}
// helper function to switch GPIO line with DCF77 signal
void set_DCF77_pin(dcf_pinstate state) {
switch (state) {
@ -248,6 +253,20 @@ void set_DCF77_pin(dcf_pinstate state) {
} // switch
} // DCF77_pulse
// helper function to sync phase of DCF output signal to start of second t
uint8_t sync_clock(time_t t) {
time_t tt = t;
// delay until start of next second
do {
tt = now();
} while (t == tt);
ESP_LOGI(TAG, "Sync on Sec %d", second(tt));
return second(tt);
}
// interrupt service routine triggered by external interrupt or internal timer
void IRAM_ATTR DCF77IRQ() {
xTaskNotifyFromISR(DCF77Task, xTaskGetTickCountFromISR(), eSetBits, NULL);

3
src/paxcounter.conf
View File

@ -85,7 +85,8 @@
#define TIME_SYNC_INTERVAL_GPS 60 // sync time each .. minutes from source GPS [default = 60], comment out means off
#define TIME_SYNC_INTERVAL_RTC 60 // sync time each .. minutes from RTC [default = 60], comment out means off
#define TIME_WRITE_INTERVAL_RTC 60 // write time each .. minutes from GPS/LORA to RTC [default = 60], comment out means off
//#define TIME_SYNC_INTERVAL_LORA 60 // sync time each .. minutes from LORA network [default = 60], comment out means off
//#define TIME_SYNC_INTERVAL_LORA 60 // sync time each .. minutes from LORA network [default = 60], comment out means off
#define TIME_SYNC_INTERVAL_DCF 60 // sync DCF signal time each .. minutes from internal time [default = 60], comment out means off
#define IF482_OFFSET 16 // IF482 serial transmit time [ms]: e.g. 9 bits * 17 bytes * 1/9600 bps = 16ms
// time zone, see https://github.com/JChristensen/Timezone/blob/master/examples/WorldClock/WorldClock.ino