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\f0\fs24 \cf0 /*\
** WH1080 decoder for OOK devices\
** Compiles with Arduino 1.0.1  \
** M Baldwin March 2013\
**\
** Resources used\
** http://www.susa.net/wordpress/2012/08/raspberry-pi-reading-wh1081-weather-sensors-using-an-rfm01-and-rfm12b/\
** http://www.sevenwatt.com/main/wh1080-protocol-v2-fsk/\
** http://lucsmall.com/2012/04/27/weather-station-hacking-part-1/\
**\
** Future updates\
** Add wind chill - unless I add it to LUA script\
** Reduce packet sent via serial for inclusion in HAH\
** Add this code to existing CC decoder combining OOK receiver and RFM12b @ 433MHz\
*/\
\
#define PIN_433 14  // AIO1 = 433 MHz receiver\
\
volatile word pulse_433;\
volatile unsigned long old = 0, packet_count = 0; \
volatile unsigned long spacing, average_interval;\
word last_433; // never accessed outside ISR's\
volatile word pulse_count = 0; //\
byte packet[10];\
byte state = 0;\
bool packet_acquired = false;\
char *direction_name[] = \{"N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE", "S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW"\};\
    \
\
// State to track pulse durations measured in the interrupt code\
ISR(PCINT1_vect)\
  \{\
    pulse_433 = 0;\
    if (digitalRead(PIN_433) == LOW)\
      \{\
        word ticker = micros();\
        pulse_433 = ticker - last_433;\
        last_433 = ticker;\
      \}\
    if (pulse_433 > 3000)\
      \{\
        state = 0;// reset data gathering\
      \}\
  \}\
\
void setup()\
  \{\
    Serial.begin(57600);\
    Serial.println();\
    Serial.println("WH1080 433MHz OOK decoder");\
  \
    pinMode(PIN_433, INPUT);\
    digitalWrite(PIN_433, 1);   // pull-up\
\
    // interrupt on pin change\
    bitSet(PCMSK1, PIN_433 - 14);\
    bitSet(PCICR, PCIE1);\
  \
    // enable interrupts\
    sei();\
    Serial.println("Interrupts set up");\
  \}\
\
void loop()\
  \{\
    byte i;\
    unsigned long now;\
    //byte *packet;\
  \
    if (pulse_433)\
      \{\
        cli();//disable interrupts and store pulse width\
        word pulse = pulse_433;\
        pulse_433 = 0;\
        sei();//re-enable interrupts\
      \
        extractData(pulse);//extract data from pulse stream\
      \
        if (state == 3)//pulse stream complete\
          \{\
            state = 4;\
            now = millis();\
            spacing = now - old;\
            old = now;\
            packet_count ++;\
            average_interval = now / packet_count;     \
         \
            Serial.print("Packet count: ");\
            Serial.println(packet_count, DEC);\
            Serial.print("Spacing: ");\
            Serial.println(spacing, DEC);\
            Serial.print("Average spacing: ");\
            Serial.println(average_interval, DEC);\
     \
            Serial.println("Packet Datastream: ");\
            Serial.println("ab cd ef gh ij kl mn op qr st");\
            for(i=0;i<=9;i++)\
              \{\
                if ((int) packet[i]<16) Serial.print('0');\
                Serial.print(packet[i], HEX);\
                Serial.print(" ");\
              \}\
              \
            Serial.print("crc: ");\
            Serial.print(calculate_crc(), HEX);\
            Serial.println((valid_crc() ? " GOOD" : " BAD"));\
  \
            Serial.print("Sensor ID: 0x");\
            Serial.println(get_sensor_id(), HEX);\
\
            Serial.print("Humidity: ");\
            Serial.print(get_humidity(), DEC);\
            Serial.println("%");\
      \
            Serial.print("Average wind speed: ");\
            Serial.print(get_avg_wind(), DEC);\
            Serial.println("m/s");\
      \
            Serial.print("Wind gust speed: ");\
            Serial.print(get_gust_wind(), DEC);\
            Serial.println("m/s");\
      \
            Serial.print("Wind direction: ");\
            //get_wind_direction();\
            Serial.println(direction_name[get_wind_direction()]);\
            \
            Serial.print("Rainfall: ");\
            Serial.print(get_rain(), DEC);\
            Serial.println("mm");\
      \
            Serial.print("Temperature: ");\
            Serial.println(get_temperature_formatted());\
            Serial.println("--------------");\
            state = 0;//reset ready for next stream\
          \}\
      \}\
  \}\
\
static void extractData(word interval)\
  \{\
    /*  state 0 == reset state \
        state 1 == looking for preamble\
        state 2 == got preamble, load rest of packet\
        state 3 == packet complete\
    */\
    bool sample;\
    byte preamble;\
    byte preamble_check = B00011110;//check if we see the end of the preamble\
    byte preamble_mask  = B00011111;//mask for preamble test (can be reduced if needed)\
    static byte packet_no, bit_no, preamble_byte;\
    if (interval >= 1400 && interval <= 1600)// 1 is indicated by 1500uS pulse\
      \{\
        sample = 1;\
      \}\
    else if (interval >= 2400  && interval <= 2600)// 0 is indicated by a 2500uS pulse\
      \{\
        sample = 0;    \
      \}\
    else\
      \{\
        state = 0;//if interval not in range reset and start looking for preamble again\
        return;\
      \} \
  \
    if(state == 0)// reset\
      \{\
        // reset stuff\
        preamble_byte = 0; \
        packet[0] = packet[1] = packet[2] = packet[3] = packet[4] = packet[5] = packet[6] = packet[7] = packet[8] = packet[9] = 0;\
        state = 1;\
      \} \
  \
      \
    if (state == 1)// acquire preamble\
      \{\
        preamble_byte <<= 1;// shift preamble byte left\
        preamble_byte |= sample;//OR with new bit\
        preamble = preamble_byte & preamble_mask;\
        if (preamble == preamble_check)// we've acquired the preamble\
          \{\
            packet_no = 0;\
            bit_no = 2;// start at 2 because we know the first two bits are 10\
            packet[0] = packet[1] = packet[2] = packet[3] = packet[4] = packet[5] = packet[6] = packet[7] = packet[8] = packet[9] = 0;\
            packet[0] <<= 1;\
            packet[0] |= 1;// first byte after preamble contains 10 so add 1\
            packet[0] <<= 1;\
            packet[0] |= 0;// first byte after preamble contains 10 so add 0 \
            state = 2;\
          \}\
        return; //not got the preamble yet so return\
      \}\
  \
    if (state == 2)// acquire packet\
      \{\
        packet[packet_no] <<= 1;\
        packet[packet_no] |= sample; //add bit to packet stream\
      \
        bit_no ++;\
        if(bit_no > 7)\
          \{\
            bit_no = 0;\
            packet_no ++;\
          \}\
    \
        if (packet_no > 9)// got full packet stream\
          \{\
            state = 3;\
          \}\
      \}\
  \}\
\
byte calculate_crc()\
  \{\
    return _crc8(packet, 9);\
  \}\
\
bool valid_crc()\
  \{\
    return (calculate_crc() == packet[9]);\
  \}\
\
int get_sensor_id()\
  \{\
    return (packet[0] << 4) + (packet[1] >> 4);\
  \}\
\
byte get_humidity()\
  \{\
    return packet[3];\
  \}\
\
byte get_avg_wind()\
  \{\
    return packet[4];\
  \}\
\
byte get_gust_wind()\
  \{\
    return packet[5];\
  \}\
\
byte get_wind_direction()\
  \{\
    int direction = packet[8] & 0x0f;\
  \}\
\
byte get_rain()\
  \{\
    return packet[7];\
  \}\
\
\
/* Temperature in deci-degrees. e.g. 251 = 25.1 */\
int get_temperature()\
  \{\
    int temperature;\
    temperature = ((packet[1] & B00000111) << 8) + packet[2];\
    // make negative\
    if (packet[1] & B00001000)\
      \{\
        temperature = -temperature;\
      \}\
    temperature -= 400;\
    return temperature;\
  \}\
\
\
String get_temperature_formatted()\
  \{\
    int temperature;\
    byte whole, partial;\
    String s;\
   \
    temperature = ((packet[1] & B00000111) << 8) + packet[2];\
    temperature -= 400;//temp offset by 400 points\
    whole = temperature / 10;\
    partial = temperature - (whole*10);\
    s = String();\
    if (packet[1] & B00001000)\
      \{\
        s += String('-');\
      \}\
    s += String(whole, DEC);\
    s += '.';\
    s += String(partial, DEC);\
    return s;\
  \}\
\
\
uint8_t _crc8( uint8_t *addr, uint8_t len)//nice crc snippet from OneWire library\
  \{\
    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;\
  \}\
\
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}