267 lines
8.9 KiB
C++
267 lines
8.9 KiB
C++
/*
|
|
|
|
///--> IMPORTANT LICENSE NOTE for this file <--///
|
|
|
|
PLEASE NOTE: There is a patent filed for the time sync algorithm used in the
|
|
code of this file. The shown implementation example is covered by the
|
|
repository's licencse, but you may not be eligible to deploy the applied
|
|
algorithm in applications without granted license by the patent holder.
|
|
|
|
*/
|
|
|
|
#if (TIME_SYNC_LORASERVER) && (HAS_LORA)
|
|
|
|
#include "timesync.h"
|
|
|
|
// Local logging tag
|
|
static const char TAG[] = __FILE__;
|
|
|
|
using namespace std::chrono;
|
|
|
|
typedef std::chrono::system_clock myClock;
|
|
typedef myClock::time_point myClock_timepoint;
|
|
typedef std::chrono::duration<long long int, std::ratio<1, 1000>>
|
|
myClock_msecTick;
|
|
|
|
TaskHandle_t timeSyncReqTask = NULL;
|
|
|
|
static uint8_t time_sync_seqNo = random(TIMEANSWERPORT_MIN, TIMEANSWERPORT_MAX);
|
|
static bool timeSyncPending = false;
|
|
static myClock_timepoint time_sync_tx[TIME_SYNC_SAMPLES];
|
|
static myClock_timepoint time_sync_rx[TIME_SYNC_SAMPLES];
|
|
|
|
// send time request message
|
|
void send_timesync_req() {
|
|
|
|
// if a timesync handshake is pending then exit
|
|
if (timeSyncPending)
|
|
return;
|
|
// else unblock timesync task
|
|
else {
|
|
ESP_LOGI(TAG, "[%0.3f] Timeserver sync request started", millis() / 1000.0);
|
|
xTaskNotifyGive(timeSyncReqTask);
|
|
}
|
|
}
|
|
|
|
// task for sending time sync requests
|
|
void process_timesync_req(void *taskparameter) {
|
|
|
|
uint8_t k;
|
|
uint16_t time_to_set_fraction_msec;
|
|
uint32_t seq_no = 0, time_to_set;
|
|
auto time_offset_ms = myClock_msecTick::zero();
|
|
|
|
while (1) {
|
|
|
|
// reset all timestamps before next sync run
|
|
time_offset_ms = myClock_msecTick::zero();
|
|
for (uint8_t i = 0; i < TIME_SYNC_SAMPLES; i++)
|
|
time_sync_tx[i] = time_sync_rx[i] = myClock_timepoint();
|
|
|
|
// wait for kickoff
|
|
ulTaskNotifyTake(pdFALSE, portMAX_DELAY);
|
|
timeSyncPending = true;
|
|
|
|
// wait until we are joined if we are not
|
|
while (!LMIC.devaddr) {
|
|
vTaskDelay(5000);
|
|
}
|
|
|
|
// collect timestamp samples
|
|
for (uint8_t i = 0; i < TIME_SYNC_SAMPLES; i++) {
|
|
// send sync request to server
|
|
payload.reset();
|
|
payload.addByte(time_sync_seqNo);
|
|
SendPayload(TIMEPORT, prio_high);
|
|
|
|
// wait for a valid timestamp from recv_timesync_ans()
|
|
while (seq_no != time_sync_seqNo) {
|
|
if (xTaskNotifyWait(0x00, ULONG_MAX, &seq_no,
|
|
pdMS_TO_TICKS(TIME_SYNC_TIMEOUT * 1000)) ==
|
|
pdFALSE) {
|
|
ESP_LOGW(TAG, "[%0.3f] Timesync handshake error: timeout",
|
|
millis() / 1000.0);
|
|
goto finish; // no valid sequence received before timeout
|
|
}
|
|
}
|
|
|
|
// process answer
|
|
k = seq_no % TIME_SYNC_SAMPLES;
|
|
|
|
// calculate time diff from collected timestamps
|
|
time_offset_ms += time_point_cast<milliseconds>(time_sync_rx[k]) -
|
|
time_point_cast<milliseconds>(time_sync_tx[k]);
|
|
|
|
// wrap around seqNo, keeping it in time port range
|
|
time_sync_seqNo = (time_sync_seqNo < TIMEANSWERPORT_MAX)
|
|
? time_sync_seqNo + 1
|
|
: TIMEANSWERPORT_MIN;
|
|
|
|
if (i < TIME_SYNC_SAMPLES - 1) {
|
|
// wait until next cycle
|
|
vTaskDelay(pdMS_TO_TICKS(TIME_SYNC_CYCLE * 1000));
|
|
} else { // before sending last time sample...
|
|
// ...send flush to open a receive window for last time_sync_answer
|
|
payload.reset();
|
|
payload.addByte(0x99);
|
|
SendPayload(RCMDPORT, prio_high);
|
|
// ...send a alive open a receive window for last time_sync_answer
|
|
// LMIC_sendAlive();
|
|
}
|
|
} // end of for loop to collect timestamp samples
|
|
|
|
// begin of time critical section: lock app irq's and I2C bus
|
|
if (!mask_user_IRQ()) {
|
|
ESP_LOGW(TAG,
|
|
"[%0.3f] Timesync handshake error: irq / i2c masking failed",
|
|
millis() / 1000.0);
|
|
goto finish; // failure
|
|
}
|
|
|
|
// average time offset over all collected diffs
|
|
time_offset_ms /= TIME_SYNC_SAMPLES;
|
|
|
|
// calculate time offset with millisecond precision using LMIC's time base,
|
|
// since we use LMIC's ostime_t txEnd as tx timestamp.
|
|
// Also apply calibration const to compensate processing time.
|
|
time_offset_ms +=
|
|
milliseconds(osticks2ms(os_getTime())) + milliseconds(TIME_SYNC_FIXUP);
|
|
|
|
// calculate absolute time in UTC epoch: convert to whole seconds, round to
|
|
// ceil, and calculate fraction milliseconds
|
|
time_to_set = (uint32_t)(time_offset_ms.count() / 1000) + 1;
|
|
// calculate fraction milliseconds
|
|
time_to_set_fraction_msec = (uint16_t)(time_offset_ms.count() % 1000);
|
|
|
|
setMyTime(time_to_set, time_to_set_fraction_msec);
|
|
|
|
// end of time critical section: release I2C bus and re-enable app irq's
|
|
unmask_user_IRQ();
|
|
|
|
finish:
|
|
timeSyncPending = false;
|
|
|
|
} // infinite while(1)
|
|
}
|
|
|
|
// called from lorawan.cpp after time_sync_req was sent
|
|
void store_time_sync_req(uint32_t timestamp) {
|
|
|
|
// if no timesync handshake is pending then exit
|
|
if (!timeSyncPending)
|
|
return;
|
|
|
|
uint8_t k = time_sync_seqNo % TIME_SYNC_SAMPLES;
|
|
time_sync_tx[k] += milliseconds(timestamp);
|
|
|
|
ESP_LOGD(TAG, "[%0.3f] Timesync request #%d of %d sent at %d.%03d",
|
|
millis() / 1000.0, k + 1, TIME_SYNC_SAMPLES, timestamp / 1000,
|
|
timestamp % 1000);
|
|
}
|
|
|
|
// process timeserver timestamp answer, called from lorawan.cpp
|
|
int recv_timesync_ans(uint8_t seq_no, uint8_t buf[], uint8_t buf_len) {
|
|
|
|
// if no timesync handshake is pending then exit
|
|
if (!timeSyncPending)
|
|
return 0; // failure
|
|
|
|
// if no time is available or spurious buffer then exit
|
|
if (buf_len != TIME_SYNC_FRAME_LENGTH) {
|
|
if (buf[0] == 0xff)
|
|
ESP_LOGI(TAG, "[%0.3f] Timeserver error: no confident time available",
|
|
millis() / 1000.0);
|
|
else
|
|
ESP_LOGW(TAG, "[%0.3f] Timeserver error: spurious data received",
|
|
millis() / 1000.0);
|
|
return 0; // failure
|
|
}
|
|
|
|
else { // we received a probably valid time frame
|
|
|
|
uint8_t k = seq_no % TIME_SYNC_SAMPLES;
|
|
uint16_t timestamp_msec; // convert 1/250th sec fractions to ms
|
|
uint32_t timestamp_sec;
|
|
|
|
// fetch timeserver time from 4 bytes containing the UTC seconds since
|
|
// unix epoch. Octet order is big endian. Casts are necessary, because buf
|
|
// is an array of single byte values, and they might overflow when shifted
|
|
timestamp_sec = ((uint32_t)buf[3]) | (((uint32_t)buf[2]) << 8) |
|
|
(((uint32_t)buf[1]) << 16) | (((uint32_t)buf[0]) << 24);
|
|
|
|
// the 5th byte contains the fractional seconds in 2^-8 second steps
|
|
timestamp_msec = 4 * buf[4];
|
|
|
|
// construct the timepoint when message was seen on gateway
|
|
time_sync_rx[k] += seconds(timestamp_sec) + milliseconds(timestamp_msec);
|
|
|
|
// we guess timepoint is recent if it newer than code compile date
|
|
if (timeIsValid(myClock::to_time_t(time_sync_rx[k]))) {
|
|
ESP_LOGD(TAG, "[%0.3f] Timesync request #%d of %d rcvd at %d.%03d",
|
|
millis() / 1000.0, k + 1, TIME_SYNC_SAMPLES, timestamp_sec,
|
|
timestamp_msec);
|
|
|
|
// inform processing task
|
|
xTaskNotify(timeSyncReqTask, seq_no, eSetBits);
|
|
|
|
return 1; // success
|
|
} else {
|
|
ESP_LOGW(TAG, "[%0.3f] Timeserver error: outdated time received",
|
|
millis() / 1000.0);
|
|
return 0; // failure
|
|
}
|
|
}
|
|
}
|
|
|
|
// adjust system time, calibrate RTC and RTC_INT pps
|
|
void IRAM_ATTR setMyTime(uint32_t t_sec, uint16_t t_msec) {
|
|
|
|
time_t time_to_set = (time_t)t_sec;
|
|
|
|
// advance time 1 sec wait time if we have no pulse clock
|
|
#if (!defined GPS_INT) && (!defined RTC_INT)
|
|
time_to_set++;
|
|
#endif
|
|
|
|
ESP_LOGD(TAG, "[%0.3f] Calculated UTC epoch time: %d.%03d sec",
|
|
millis() / 1000.0, time_to_set, t_msec);
|
|
|
|
if (timeIsValid(time_to_set)) {
|
|
|
|
// wait until top of second with millisecond precision
|
|
vTaskDelay(pdMS_TO_TICKS(1000 - t_msec));
|
|
|
|
// set RTC time and calibrate RTC_INT pulse on top of second
|
|
#ifdef HAS_RTC
|
|
set_rtctime(time_to_set, no_mutex);
|
|
#endif
|
|
|
|
// sync pps timer to top of second
|
|
#if (!defined GPS_INT && !defined RTC_INT)
|
|
timerWrite(ppsIRQ, 0); // reset pps timer
|
|
CLOCKIRQ(); // fire clock pps, this advances time 1 sec
|
|
#endif
|
|
|
|
setTime(time_to_set); // set the time on top of second
|
|
|
|
timeSource = _lora;
|
|
timesyncer.attach(TIME_SYNC_INTERVAL * 60, timeSync); // regular repeat
|
|
ESP_LOGI(TAG, "[%0.3f] Timesync finished, time was adjusted",
|
|
millis() / 1000.0);
|
|
} else
|
|
ESP_LOGW(TAG, "[%0.3f] Timesync failed, outdated time calculated",
|
|
millis() / 1000.0);
|
|
}
|
|
|
|
void timesync_init() {
|
|
// create task for timeserver handshake processing, called from main.cpp
|
|
xTaskCreatePinnedToCore(process_timesync_req, // task function
|
|
"timesync_req", // name of task
|
|
2048, // stack size of task
|
|
(void *)1, // task parameter
|
|
3, // priority of the task
|
|
&timeSyncReqTask, // task handle
|
|
1); // CPU core
|
|
}
|
|
|
|
#endif |