Merge pull request #28 from prashantdev/master

Making it simpler to use multiple OneWire buses with an arduino array

Author: milesburton

DallasTemperature.cpp

@@ -17,19 +17,22 @@ extern "C" {
 }
 #endif
 
+DallasTemperature::DallasTemperature() {}
 DallasTemperature::DallasTemperature(OneWire* _oneWire)
 #if REQUIRESALARMS
     : _AlarmHandler(&defaultAlarmHandler)
 #endif
 {
+    setOneWire(_oneWire);
+}
+void DallasTemperature::setOneWire(OneWire* _oneWire){
     _wire = _oneWire;
     devices = 0;
     parasite = false;
     bitResolution = 9;
     waitForConversion = true;
     checkForConversion = true;
 }
-
 // initialise the bus
 void DallasTemperature::begin(void)
 {

DallasTemperature.h

@@ -64,8 +64,11 @@ class DallasTemperature
 {
   public:
 
+  DallasTemperature();
   DallasTemperature(OneWire*);
 
+  void setOneWire(OneWire*);
+
   // initialise bus
   void begin(void);
 

README.md

@@ -1,6 +1,14 @@
 Arduino Library for Dallas Temperature ICs
 ==========================================
 
+=========MODIFICATIONS BY PRASHANT========
+An extra no arguments constructor to simplify multiple OneWire buse use, 
+allowing for easier construction of arrays of OneWire buses,
+in the limited environment provided by Arduino.
+See the Multibus_simple example illustrating a use-case of the extension.
+Use in conjunction with my modification of the OneWire library.
+=========END MODIFICATIONS BY PRASHANT========
+
 Usage
 -----
 

examples/Multibus_simple/Multibus_simple.ino

@@ -0,0 +1,48 @@
+#include <OneWire.h>
+#include <DallasTemperature.h>
+
+int oneWirePins[]={3,7};//OneWire DS18x20 temperature sensors on these wires
+const int oneWirePinsCount=sizeof(oneWirePins)/sizeof(int);
+
+OneWire ds18x20[oneWirePinsCount];
+DallasTemperature sensor[oneWirePinsCount];
+
+
+void setup(void) {
+  // start serial port
+  Serial.begin(9600);
+  Serial.println("Dallas Temperature Multiple Bus Control Library Simple Demo");
+  Serial.print("============Ready with ");
+  Serial.print(oneWirePinsCount);
+  Serial.println(" Sensors================");
+  
+  // Start up the library on all defined bus-wires
+  DeviceAddress deviceAddress;
+  for (int i=0; i<oneWirePinsCount; i++) {;
+    ds18x20[i].setPin(oneWirePins[i]);
+    sensor[i].setOneWire(&ds18x20[i]);
+    sensor[i].begin();
+    if (sensor[i].getAddress(deviceAddress, 0)) sensor[i].setResolution(deviceAddress, 12);
+  }
+  
+}
+
+void loop(void) {
+  // call sensors.requestTemperatures() to issue a global temperature 
+  // request to all devices on the bus
+  Serial.print("Requesting temperatures...");
+  for (int i=0; i<oneWirePinsCount; i++) {
+    sensor[i].requestTemperatures();
+  }
+  Serial.println("DONE");
+  
+  delay(1000);
+  for (int i=0; i<oneWirePinsCount; i++) {
+    float temperature=sensor[i].getTempCByIndex(0);
+    Serial.print("Temperature for the sensor ");
+    Serial.print(i);
+    Serial.print(" is ");
+    Serial.println(temperature);
+  }
+  Serial.println();
+}