ds.cpp

#include "GrowduinoFirmware.h"

#include <OneWire.h>

//byte addr[8];
byte data[12];
//byte present = 0;
byte type_s;
int celsius;


int ds_read(OneWire ds) {
  int result = MINVALUE;
#ifdef WATCHDOG
  SERIAL.print(F("Watchdog reset DS read"));
  wdt_reset();
#endif

  for (int i = 0; i < 10; i++) {

    result = ds_read_inner(ds);
#ifdef WATCHDOG
    SERIAL.print(F("."));
    wdt_reset();
#endif
    if (result != MINVALUE ) {
#ifdef WATCHDOG
      SERIAL.println(F(" done"));
      wdt_reset();
#endif
      return result;
    }
    delay(10);
  }
#ifdef WATCHDOG
  SERIAL.println(F(" done"));
  wdt_reset();
#endif
  return result;
}


int ds_read_inner(OneWire ds) {

  byte addr[8];
  ds.reset_search();
  delay(10);
  int res = ds.search(addr);

  if (res == 0) {
    return MINVALUE;
  }

  if (addr[0] == 0) {
    type_s = 1;
  } else {
    type_s = 0;
  }
  ds.reset();
  ds.select(addr);
  ds.write(0x44, 1);        // start conversion, with parasite power on at the end
  delay(1000);
  ds.reset();
  ds.select(addr);
  ds.write(0xBE);
  for (int i = 0; i < 9; i++) {           // we need 9 bytes
    data[i] = ds.read();
  }
  int16_t raw = (data[1] << 8) | data[0];
  if (type_s) {
    raw = raw << 3; // 9 bit resolution default
    if (data[7] == 0x10) {
      // "count remain" gives full 12 bit resolution
      raw = (raw & 0xFFF0) + 12 - data[6];
    }
  } else {
    byte cfg = (data[4] & 0x60);
    // at lower res, the low bits are undefined, so let's zero them
    if (cfg == 0x00) raw = raw & ~7;  // 9 bit resolution, 93.75 ms
    else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
    else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
    //// default is 12 bit resolution, 750 ms conversion time
  }
  celsius = raw * 10 / 16;
  return celsius;
}