Arduino Yun web_temperature5 files

one_wire.ino

@@ -0,0 +1,145 @@
+/*
+  read_1_wire()
+  -------------
+  Y. Masur (7/2007), adapted of F.Benninger V1.05 original code.
+  10.08.2014 - YM: values in 0.1 degree
+  
+  Read 1 wire temperature sensors. Each time the function is called, chose the next avaiable device adresse
+  and get the temp value, convert it in degree C x 10.
+  Eg. 23.52 °C -> 235
+  
+  Input parameters:
+  - pval: pointer on a int table, with max_scan elements (as val[3])
+  - max_scan: dimension of the table above (eg. max_scan = 3)
+  
+  Modified values:
+  - content of pval[], one element at each call, with the temperature in degree x 10
+  
+  Return value: 
+  0 : conversion is done, then stored
+  1 : the max device nb is reached, reset index
+  -1: CRC error, data not stored
+  -2: no device found
+  
+*/
+#define PRINT_VAL 0
+
+int read_1_wire(int *pval = NULL, byte max_scan = 8)
+{
+  static byte scan = 0;
+  byte i;
+  byte present = 0;
+  byte data[12];
+  byte addr[8];
+
+  if ( !ds.search(addr) || scan >= max_scan) 
+  {
+#if PRINT_VAL 
+      Serial.print("No more addresses. Reset search.\n");
+#endif      
+      ds.reset_search();
+      scan = 0;
+      return 1;  // 1 given: terminated
+  }
+
+#if PRINT_VAL   
+  Serial.print("R=");
+  for( i = 0; i < 8; i++)
+  {
+    Serial.print(addr[i], HEX);
+    Serial.print(" ");
+  }
+#endif  
+  if ( OneWire::crc8( addr, 7) != addr[7])
+  {
+#if PRINT_VAL     
+      Serial.print("CRC error!\n");
+#endif
+      return -1;
+  }
+
+#if PRINT_VAL   
+  if ( addr[0] == 0x10)
+  {   
+      Serial.print("Device is a DS18S20 family device +-0.5 deg\n");
+  }
+  else if ( addr[0] == 0x28)
+  {
+      Serial.print("Device is a DS18B20 family device +- 0.5 deg\n");
+  }
+  else if ( addr[0] == 0x22)
+  {
+      Serial.print("Device is a DS1822 family device +-2 deg\n");
+  }
+  else
+  {
+      Serial.print("Device family is not recognized: 0x");
+      Serial.println(addr[0],HEX);
+      return -2;
+  }
+#endif
+
+  ds.reset();
+  ds.select(addr);
+  ds.write(0x44,1);         // start conversion, with parasite power on at the end
+  delay(10);               // maybe 750ms is enough, maybe not
+  // we might do a ds.depower() here, but the reset will take care of it.
+
+  present = ds.reset();
+  ds.select(addr);    
+  ds.write(0xBE);         // Read Scratchpad
+
+#if PRINT_VAL   
+  Serial.print("P=");
+  Serial.print(present,HEX);
+  Serial.print(" ");
+#endif
+
+  for ( i = 0; i < 9; i++) 
+  {           // we need 9 bytes
+    data[i] = ds.read();
+#if PRINT_VAL     
+    Serial.print(data[i], HEX);
+    Serial.print(" ");
+#endif    
+  }
+
+#if PRINT_VAL  
+  Serial.print(" CRC=");
+  Serial.print( OneWire::crc8( data, 8), HEX);
+  Serial.println();
+#endif
+  byte LowByte = data[0];
+  byte HighByte = data[1];
+
+  int TReading = (HighByte << 8) + LowByte;
+  int SignBit = TReading & 0x8000;  // test most sig bit
+
+  if (SignBit) // negative
+  {
+    int TReading = (TReading ^ 0xffff) + 1; // 2's comp
+  }
+  int Tc_100 = (6 * TReading) + TReading / 4;    // multiply by (100 * 0.0625) or 6.25
+
+#if PRINT_VAL   
+  int Whole = Tc_100 / 100;  // separate off the whole and fractional portions
+  int Fract = Tc_100 % 100;
+  if (SignBit) // If its negative
+  {
+     Serial.print("-");
+  }
+  Serial.print(Whole);
+  Serial.print(".");
+  if (Fract < 10)
+  {
+     Serial.print("0");
+  }
+  Serial.print(Fract);
+  Serial.println("\n");
+#endif
+
+  //Storage, rounded at 0.05
+  pval[scan] = (Tc_100+5)/10;
+  scan++;
+  return 0;
+}// end of read_1_wire()