/* NOTE: The IF482 Generator needs an high precise 1 Hz clock signal which cannot be acquired in suitable precision on the ESP32 SoC itself. Additional clocking hardware is required, ususally the clock signal is generated by external RTC or GPS which can generate a precise time pulse signal (+/- 2ppm). In this example code we use a Maxim DS3231 RTC chip, and configure the chips's interrupt output pin as clock. The clock signal triggers an interrupt on the ESP32, which controls the realtime output of IF482 telegram. This is why code in IF482.cpp depends on code in RTCTIME.cpp. */ /////////////////////////////////////////////////////////////////////////////// /* IF482 Generator to control clocks with IF482 telegram input (e.g. BÜRK BU190) Example IF482 telegram: "OAL160806F170400" IF482 Specification: http://www.mobatime.com/fileadmin/user_upload/downloads/TE-112023.pdf The IF 482 telegram is a time telegram, which sends the time and date information as ASCII characters through the serial interface RS 232 or RS 422. Communication parameters: Baud rate: 9600 Bit/s Data bits 7 Parity: even Stop bit: 1 Jitter: < 50ms Interface : RS232 or RS422 Synchronization: Telegram ends at the beginning of the second specified in the telegram Cycle: 1 second Format of ASCII telegram string: Byte Meaning ASCII Hex 1 Start of telegram O 4F 2 Monitoring* A 41 3 Time-Season** W/S/U/L 57 or 53 4 Year tens 0 .. 9 30 .. 39 5 Year unit 0 .. 9 30 .. 39 6 Month tens 0 or 1 30 or 31 7 Month unit 0 .. 9 30 .. 39 8 Day tens 0 .. 3 30 .. 33 9 Day unit 0 .. 9 30 .. 39 10 Day of week*** 1 .. 7 31 .. 37 11 Hours tens 0 .. 2 30 .. 32 12 Hours unit 0 .. 9 30 .. 39 13 Minutes tens 0 .. 5 30 .. 35 14 Minutes unit 0 .. 9 30 .. 39 15 Seconds tens 0 .. 5 30 .. 35 16 Seconds unit 0 .. 9 30 .. 39 17 End of telegram CR 0D *) Monitoring: With a correctly received time in the sender unit, the ASCII character 'A' is issued. If 'M' is issued, this indicates that the sender was unable to receive any time signal for over 12 hours (time is accepted with ‘A’ and ‘M’). **) Season: W: Standard time, S: Season time, U: UTC time (not supported by all systems), L: Local Time ***) Day of week: not evaluated by model BU-190 */ /////////////////////////////////////////////////////////////////////////////// #ifdef HAS_IF482 #ifdef HAS_DCF77 #error You must define at most one of IF482 or DCF77! #endif #include "if482.h" // Local logging tag static const char TAG[] = "main"; #define IF482_FRAME_SIZE (17) #define IF482_PULSE_DURATION (1000) // select internal / external clock #if defined RTC_INT && defined RTC_CLK #define PPS RTC_CLK #elif defined GPS_INT && defined GPS_CLK #define PPS GPS_CLK #else #define PPS IF482_PULSE_DURATION #endif HardwareSerial IF482(2); // use UART #2 (note: #1 may be in use for serial GPS) // initialize and configure IF482 Generator int if482_init(void) { // open serial interface IF482.begin(HAS_IF482); // setup timepulse timepulse_init(PPS); // start if482 serial output feed task xTaskCreatePinnedToCore(if482_loop, // task function "if482loop", // name of task 2048, // stack size of task (void *)1, // parameter of the task 4, // priority of the task &ClockTask, // task handle 0); // CPU core assert(ClockTask); // has clock task started? // timepulse_start(); // start pulse return 1; // success } // if482_init String IF482_Out(time_t tt) { time_t t = myTZ.toLocal(tt); char mon, buf[14], out[IF482_FRAME_SIZE]; switch (timeStatus()) { // indicates if time has been set and recently synced case timeSet: // time is set and is synced mon = 'A'; break; case timeNeedsSync: // time had been set but sync attempt did not succeed mon = 'M'; break; default: // time not set, no valid time mon = '?'; break; } // switch // do we have confident time/date? if ((timeStatus() == timeSet) || (timeStatus() == timeNeedsSync)) snprintf(buf, sizeof(buf), "%02u%02u%02u%1u%02u%02u%02u", year(t) - 2000, month(t), day(t), weekday(t), hour(t), minute(t), second(t)); else snprintf(buf, sizeof(buf), "000000F000000"); // no confident time/date // output IF482 telegram snprintf(out, sizeof(out), "O%cL%s\r", mon, buf); ESP_LOGD(TAG, "IF482 = %s", out); return out; } void if482_loop(void *pvParameters) { configASSERT(((uint32_t)pvParameters) == 1); // FreeRTOS check TickType_t wakeTime; const TickType_t tTx = tx_time(HAS_IF482); // duration of telegram transmit // phase 1: sync task on top of second const TickType_t t0 = xTaskGetTickCount(); // moment of start top of second sync_clock(); // delay until top of second timepulse_start(); // start timepulse 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...) const TickType_t tOffset = wakeTime - t0; const TickType_t tShot = (tOffset < tTx) ? (1000 - tOffset - tTx) : (tOffset - tTx); ESP_LOGI(TAG, "IF482 signal synced with clock, tShot=%dms", tShot); // phase 2: sync task on time pulse interrupt 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...) // select clock scale #if (PPS == IF482_PULSE_DURATION) // we don't need clock rescaling // wait until it's time to start transmit telegram for next second vTaskDelayUntil(&wakeTime, tShot); // sets waketime to moment of tShot IF482.print(IF482_Out(now() + 1)); #elif (PPS > IF482_PULSE_DURATION) // we need upclocking for (uint8_t i = 1; i <= PPS / IF482_PULSE_DURATION; i++) { vTaskDelayUntil(&wakeTime, tShot); // sets waketime to moment of shot IF482.print(IF482_Out(now() + 1)); } #elif (PPS < IF482_PULSE_DURATION) // we need downclocking, not yet implemented #error Timepulse is too low for IF482! #endif } // forever } // if482_loop() // calculate serial tx time from IF482 serial settings TickType_t tx_time(unsigned long baud, uint32_t config, int8_t rxPin, int8_t txPins) { uint32_t datenbits = ((config & 0x0c) >> 2) + 5; uint32_t stopbits = ((config & 0x20) >> 5) + 1; return pdMS_TO_TICKS( round(((1 + datenbits + stopbits) * IF482_FRAME_SIZE * 1000.0 / baud))); } #endif // HAS_IF482