Всем привет! Собрал схемку для приема и обработки сигнала от внешнего датчика погодной станции. Код и схема подключения взяты у товарища, что декодировал протокол. При питании от компьютерного USB, или импульсного блока питания от приемника идет случайный шум (зеленый диод, что на активности приемника, постоянно моргает). При питании от батареи - все отлично, пакеты приходят, контрольные суммы совпадают (зеленый диод мигает только перед полученным пакетом). Пробовал собирать схему на UNO и Iskra Neo, пробовал блоки питания: 5В 1А robiton, 5В 2А от Ipad, 12В от gigabyte brix - схема нормально работает только от батареи крона или сборки из AA. Пробовал другие скетчи - просто дамп эфира - такая же картина, хаос от блока питания, хорошие редкие сигналы от батареи. Куда копать? Спойлер: Код Код (C++): /* Updated code for receiving data from WH2 weather station This code implements timeouts to make decoding more robust Decodes received packets and writes a summary of each packet to the Arduino's serial port Created by Luc Small on 19 July 2013. Released into the public domain. */ // Read data from 433MHz receiver on digital pin 2 #define RF_IN 2 // For better efficiency, the port is read directly // the following two lines should be changed appropriately // if the line above is changed. #define RF_IN_RAW PIND2 #define RF_IN_PIN PIND // Port that is hooked to LED to indicate a packet has been received #define LED_PACKET A2 #define LED_ACTIVITY A1 #define COUNTER_RATE 3200-1 // 16,000,000Hz / 3200 = 5000 interrupts per second, ie. 200us between interrupts // 1 is indicated by 500uS pulse // wh2_accept from 2 = 400us to 3 = 600us #define IS_HI_PULSE(interval) (interval >= 2 && interval <= 3) // 0 is indicated by ~1500us pulse // wh2_accept from 7 = 1400us to 8 = 1600us #define IS_LOW_PULSE(interval) (interval >= 7 && interval <= 8) // worst case packet length // 6 bytes x 8 bits x (1.5 + 1) = 120ms; 120ms = 200us x 600 #define HAS_TIMED_OUT(interval) (interval > 600) // we expect 1ms of idle time between pulses // so if our pulse hasn't arrived by 1.2ms, reset the wh2_packet_state machine // 6 x 200us = 1.2ms #define IDLE_HAS_TIMED_OUT(interval) (interval > 6) // our expected pulse should arrive after 1ms // we'll wh2_accept it if it arrives after // 4 x 200us = 800us #define IDLE_PERIOD_DONE(interval) (interval >= 4) // Shorthand for tests #define RF_HI (digitalRead(RF_IN) == HIGH) #define RF_LOW (digitalRead(RF_IN) == LOW) //#define RF_HI (bit_is_set(RF_IN_PIN, RF_IN_RAW)) //#define RF_LOW (bit_is_clear(RF_IN_PIN, RF_IN_RAW)) // wh2_flags #define GOT_PULSE 0x01 #define LOGIC_HI 0x02 volatile byte wh2_flags = 0; volatile byte wh2_packet_state = 0; volatile int wh2_timeout = 0; byte wh2_packet[5]; byte wh2_calculated_crc; ISR(TIMER1_COMPA_vect) { static byte sampling_state = 0; static byte count; static boolean was_low = false; switch (sampling_state) { case 0: // waiting wh2_packet_state = 0; if (RF_HI) { digitalWrite(LED_ACTIVITY, HIGH); if (was_low) { count = 0; sampling_state = 1; was_low = false; } } else { digitalWrite(LED_ACTIVITY, LOW); was_low = true; } break; case 1: // acquiring first pulse count++; // end of first pulse if (RF_LOW) { if (IS_HI_PULSE(count)) { wh2_flags = GOT_PULSE | LOGIC_HI; sampling_state = 2; count = 0; } else if (IS_LOW_PULSE(count)) { wh2_flags = GOT_PULSE; // logic low sampling_state = 2; count = 0; } else { sampling_state = 0; } } break; case 2: // observe 1ms of idle time count++; if (RF_HI) { if (IDLE_HAS_TIMED_OUT(count)) { sampling_state = 0; } else if (IDLE_PERIOD_DONE(count)) { sampling_state = 1; count = 0; } } break; } if (wh2_timeout > 0) { wh2_timeout++; if (HAS_TIMED_OUT(wh2_timeout)) { wh2_packet_state = 0; wh2_timeout = 0; } } } void setup() { delay(10000); Serial.begin(9600); Serial.println("BetterWH2"); pinMode(LED_PACKET, OUTPUT); pinMode(RF_IN, INPUT); TCCR1A = 0x00; TCCR1B = 0x09; TCCR1C = 0x00; OCR1A = COUNTER_RATE; TIMSK1 = 0x02; // enable interrupts sei(); } void loop() { static unsigned long old = 0, packet_count = 0, bad_count = 0, average_interval; unsigned long spacing, now; byte i; if (wh2_flags) { if (wh2_accept()) { // calculate the CRC wh2_calculate_crc(); now = millis(); spacing = now - old; old = now; packet_count++; average_interval = now / packet_count; if (!wh2_valid()) { bad_count++; } // flash green led to say got packet digitalWrite(LED_PACKET, HIGH); delay(100); digitalWrite(LED_PACKET, LOW); Serial.print(packet_count, DEC); Serial.print(" | "); Serial.print(bad_count, DEC); Serial.print(" | "); Serial.print(spacing, DEC); Serial.print(" | "); Serial.print(average_interval, DEC); Serial.print(" | "); for (i = 0; i < 5; i++) { Serial.print("0x"); Serial.print(wh2_packet[i], HEX); Serial.print("/"); Serial.print(wh2_packet[i], DEC); Serial.print(" "); } Serial.print("| Sensor ID: 0x"); Serial.print(wh2_sensor_id(), HEX); Serial.print(" | "); Serial.print(wh2_humidity(), DEC); Serial.print("% | "); Serial.print(wh2_temperature()/10, DEC); Serial.print(" | "); Serial.println((wh2_valid() ? "OK" : "BAD")); } wh2_flags = 0x00; } } // processes new pulse boolean wh2_accept() { static byte packet_no, bit_no, history; // reset if in initial wh2_packet_state if (wh2_packet_state == 0) { // should history be 0, does it matter? history = 0xFF; wh2_packet_state = 1; // enable wh2_timeout wh2_timeout = 1; } // fall thru to wh2_packet_state one // acquire preamble if (wh2_packet_state == 1) { // shift history right and store new value history <<= 1; // store a 1 if required (right shift along will store a 0) if (wh2_flags & LOGIC_HI) { history |= 0x01; } // check if we have a valid start of frame // xxxxx110 if ((history & B00000111) == B00000110) { // need to clear packet, and counters packet_no = 0; // start at 1 becuase only need to acquire 7 bits for first packet byte. bit_no = 1; wh2_packet[0] = wh2_packet[1] = wh2_packet[2] = wh2_packet[3] = wh2_packet[4] = 0; // we've acquired the preamble wh2_packet_state = 2; } return false; } // acquire packet if (wh2_packet_state == 2) { wh2_packet[packet_no] <<= 1; if (wh2_flags & LOGIC_HI) { wh2_packet[packet_no] |= 0x01; } bit_no ++; if (bit_no > 7) { bit_no = 0; packet_no ++; } if (packet_no > 4) { // start the sampling process from scratch wh2_packet_state = 0; // clear wh2_timeout wh2_timeout = 0; return true; } } return false; } void wh2_calculate_crc() { wh2_calculated_crc = crc8(wh2_packet, 4); } bool wh2_valid() { return (wh2_calculated_crc == wh2_packet[4]); } int wh2_sensor_id() { return (wh2_packet[0] << 4) + (wh2_packet[1] >> 4); } byte wh2_humidity() { return wh2_packet[3]; } /* Temperature in deci-degrees. e.g. 251 = 25.1 */ int wh2_temperature() { int temperature; temperature = ((wh2_packet[1] & B00000111) << 8) + wh2_packet[2]; // make negative if (wh2_packet[1] & B00001000) { temperature = -temperature; } return temperature; } uint8_t crc8( uint8_t *addr, uint8_t len) { uint8_t crc = 0; // Indicated changes are from reference CRC-8 function in OneWire library while (len--) { uint8_t inbyte = *addr++; for (uint8_t i = 8; i; i--) { uint8_t mix = (crc ^ inbyte) & 0x80; // changed from & 0x01 crc <<= 1; // changed from right shift if (mix) crc ^= 0x31;// changed from 0x8C; inbyte <<= 1; // changed from right shift } } return crc; }
