diff --git a/TSYS01.cpp b/TSYS01.cpp
index bdb6555..14e62eb 100644
--- a/TSYS01.cpp
+++ b/TSYS01.cpp
@@ -1,54 +1,76 @@
 #include "TSYS01.h"
 #include <Wire.h>
 
-#define TSYS01_ADDR                        0x77  
+#ifdef TSYS01_USE_LOW_POWER
+	// Use deep sleep instead of delay() to save power. Get the library from https://github.com/LowPowerLab/LowPower
+	#warning "TSYS01_USE_LOW_POWER: enabled"
+	#include <LowPower.h>
+#endif
+
 #define TSYS01_RESET                       0x1E
 #define TSYS01_ADC_READ                    0x00
 #define TSYS01_ADC_TEMP_CONV               0x48
 #define TSYS01_PROM_READ                   0XA0
 
-TSYS01::TSYS01() {
+TSYS01::TSYS01(uint8_t i2cAddress)
+	: mAddress(i2cAddress)
+{}
 
+bool TSYS01::isValid() {
+	return mAddress != 0;
 }
 
 void TSYS01::init() {
+	Wire.beginTransmission(mAddress);
+	if (Wire.endTransmission() != 0) {
+		mAddress = 0;
+		return;
+	}
+
 	// Reset the TSYS01, per datasheet
-	Wire.beginTransmission(TSYS01_ADDR);
+	Wire.beginTransmission(mAddress);
 	Wire.write(TSYS01_RESET);
 	Wire.endTransmission();
 	
+ 	#ifdef TSYS01_USE_LOW_POWER
+	LowPower.powerDown(SLEEP_15MS, ADC_OFF, BOD_OFF);
+	#else
 	delay(10);
+	#endif
 	
 		// Read calibration values
 	for ( uint8_t i = 0 ; i < 8 ; i++ ) {
-		Wire.beginTransmission(TSYS01_ADDR);
+		Wire.beginTransmission(mAddress);
 		Wire.write(TSYS01_PROM_READ+i*2);
 		Wire.endTransmission();
 
-		Wire.requestFrom(TSYS01_ADDR,2);
+		Wire.requestFrom(mAddress, uint8_t(2));
 		C[i] = (Wire.read() << 8) | Wire.read();
 	}
 
 }
 
 void TSYS01::read() {
-	
-	Wire.beginTransmission(TSYS01_ADDR);
+	Wire.beginTransmission(mAddress);
 	Wire.write(TSYS01_ADC_TEMP_CONV);
 	Wire.endTransmission();
- 
-	delay(10); // Max conversion time per datasheet
 	
-	Wire.beginTransmission(TSYS01_ADDR);
+	#ifdef TSYS01_USE_LOW_POWER
+	LowPower.powerDown(SLEEP_15MS, ADC_OFF, BOD_OFF);
+	#else
+	delay(10); // Max conversion time per datasheet
+	#endif
+
+	Wire.beginTransmission(mAddress);
 	Wire.write(TSYS01_ADC_READ);
 	Wire.endTransmission();
-
-	Wire.requestFrom(TSYS01_ADDR,3);
+	
+	Wire.requestFrom(mAddress, uint8_t(3));
 	D1 = 0;
 	D1 = Wire.read();
 	D1 = (D1 << 8) | Wire.read();
 	D1 = (D1 << 8) | Wire.read();
-
+	
 	calculate();
 }
 
diff --git a/TSYS01.h b/TSYS01.h
index 06047ee..ccd94b4 100644
--- a/TSYS01.h
+++ b/TSYS01.h
@@ -36,8 +36,10 @@ THE SOFTWARE.
 class TSYS01 {
 public:
 
-	TSYS01();
 
+	TSYS01(uint8_t i2cAddress = 0x77);
+
+	bool isValid();
 	void init();
 
 	/** The read from I2C takes up for 40 ms, so use sparingly is possible.
@@ -59,6 +61,7 @@ class TSYS01 {
 	uint32_t D1;
 	float TEMP;
 	uint32_t adc;
+	uint8_t mAddress;
 
 	/** Performs calculations per the sensor data sheet for conversion and
 	 *  second order compensation.