Added ID check to begin()

Adafruit_BMP085.cpp

@@ -21,13 +21,15 @@ Adafruit_BMP085::Adafruit_BMP085() {
 }
 
 
-void Adafruit_BMP085::begin(uint8_t mode) {
+boolean Adafruit_BMP085::begin(uint8_t mode) {
   if (mode > BMP085_ULTRAHIGHRES) 
     mode = BMP085_ULTRAHIGHRES;
   oversampling = mode;
 
   Wire.begin();
 
+  if (read8(0xD0) != 0x55) return false;
+
   /* read calibration data */
   ac1 = read16(BMP085_CAL_AC1);
   ac2 = read16(BMP085_CAL_AC2);

Adafruit_BMP085.h

@@ -51,7 +51,7 @@
 class Adafruit_BMP085 {
  public:
   Adafruit_BMP085();
-  void begin(uint8_t mode = BMP085_ULTRAHIGHRES);  // by default go highres
+  boolean begin(uint8_t mode = BMP085_ULTRAHIGHRES);  // by default go highres
   float readTemperature(void);
   int32_t readPressure(void);
   float readAltitude(float sealevelPressure = 101325); // std atmosphere

examples/BMP085test/BMP085test.pde

@@ -28,7 +28,10 @@ Adafruit_BMP085 bmp;
   
 void setup() {
   Serial.begin(9600);
-  bmp.begin();  
+  if (!bmp.begin()) {
+	Serial.println("Could not find a valid BMP085 sensor, check wiring!");
+	while (1) {}
+  }
 }
   
 void loop() {