diff --git a/README.md b/README.md
index 18fb41f..03e419a 100644
--- a/README.md
+++ b/README.md
@@ -30,45 +30,46 @@ The `init_ina236` function allows to set up the INA236 either with default value
 # Second parameter
 # Change Vshct of the INA236.
 # Choose between 8 different conversion times for the shunt voltage measurment
-# 1. 140us
-# 2. 204us
-# 3. 332us
-# 4. 588us
-# 5. 1100us
-# 6. 2116us
-# 7. 4156us
-# 8. 8244us
+# 0. 140us
+# 1. 204us
+# 2. 332us
+# 3. 588us
+# 4. 1100us
+# 5. 2116us
+# 6. 4156us
+# 7. 8244us
 # Default initialization with '1100us'
 # Third parameter
 # Change Vbusct of the INA236.
 # Choose between 8 different conversion times for the shunt voltage measurment
-# 1. 140us
-# 2. 204us
-# 3. 332us
-# 4. 588us
-# 5. 1100us
-# 6. 2116us
-# 7. 4156us
-# 8. 8244us
+# 0. 140us
+# 1. 204us
+# 2. 332us
+# 3. 588us
+# 4. 1100us
+# 5. 2116us
+# 6. 4156us
+# 7. 8244us
 # Default initialization with '1100us'
 # Fourth parameter
 # Change Avg of the INA236.
 # Choose between 8 different values to define the amount that is to be averaged
-# 1. 1
-# 2. 4
-# 3. 16
-# 4. 64
-# 5. 128
-# 6. 256
-# 7. 512
-# 8. 1024
+# 0. 1
+# 1. 4
+# 2. 16
+# 3. 64
+# 4. 128
+# 5. 256
+# 6. 512
+# 7. 1024
 # Default initialization with '1'
 # Fifth parameter
 # Change ADCRange of the INA236.
 # Choose between 2 different values that are to be used for the internal calculations
-# 1. ±81.92mV
-# 2. ±20.48mV
+# 0. ±81.92mV
+# 1. ±20.48mV
 # Default initialization with '±81.92mV'
+
 # Sixth parameter
 # Change Address of the INA236.
 # Choose between 4 different values which define the I2C Adress that is to be used for the communication
@@ -135,16 +136,16 @@ The `mask_enable` function allows to choose between 10 different options in the
 ```python
 # Choose a option in the alert register of the INA236.
 # Choose between 10 different options to define the part of the register that is to be used
-# 1. SOL (Shunt Over-limit)
-# 2. SUL (Shunt Under-limit)
-# 3. BOL (Bus Over-limit)
-# 4. BUL (Bus Under-limit)
-# 5. POL (Power Over-limit)
-# 6. CNVR (Conversion Ready)
-# 7. MemError
-# 8. AFF (Alert Function Flag)
-# 9. CVRF (Conversion Ready Flag)
-# 10. OVF (Math Over-flow)
+# 0. SOL (Shunt Over-limit)
+# 1. SUL (Shunt Under-limit)
+# 2. BOL (Bus Over-limit)
+# 3. BUL (Bus Under-limit)
+# 4. POL (Power Over-limit)
+# 5. CNVR (Conversion Ready)
+# 6. MemError
+# 7. AFF (Alert Function Flag)
+# 8. CVRF (Conversion Ready Flag)
+# 9. OVF (Math Over-flow)
 # Default initialization with '1'
 INA236.mask_enable(1);
 ```
@@ -163,24 +164,24 @@ INA236.write_alert_limit();
 ```
 
 ## Read from the alert register
-The `read_alert_limit` function enables reading from the alert register of the INA236.
+The `print_alert_limit` function enables reading from the alert register of the INA236 and printed to serial output.
 ```python
 # Read from the alert register of the INA236.
-INA236.read_alert_limit();
+INA236.print_alert_limit();
 ```
 
 ## Read the manufacturer ID
-The `manufacturer_ID` function enables the manufacturer ID of the INA236 to be read out.
+The `print_manufacturer_ID` function enables the manufacturer ID of the INA236 to be read and printed to serial output.
 ```python
 # Read from the manufacturer ID register of the INA236.
-INA236.manufacturer_ID();
+INA236.print_manufacturer_ID();
 ```
 
 ## Read the device ID
-The `device_ID` function enables the device ID of the INA236 to be read.
+The `print_device_ID` function enables the device ID of the INA236 to be read and printed to serial output.
 ```python
 # Read from the device ID register of the INA236.
-INA236.device_ID();
+INA236.print_device_ID();
 ```
 
 ## Supported targets
diff --git a/SBC_DVA.cpp b/SBC_DVA.cpp
index cfab699..5b23460 100644
--- a/SBC_DVA.cpp
+++ b/SBC_DVA.cpp
@@ -11,50 +11,56 @@
 
 // Constructor //
 
-SBCDVA::SBCDVA(uint8_t address) {
-  Address = address;
+SBCDVA::SBCDVA(uint8_t _address, TwoWire* _wire) {
+  wire = _wire;
+  Address = _address;
   Current_lsb = 0;
   Lsb = _LSB[0];
-  Address = _ADDRESS_A[0];
   Mode = _MODE[7];
   Vshct = _VSHCT[4];
   Vbusct = _VBUSCT[4];
   Avg = _AVG[0];
   Adcrange = _ADCRANGE[0];
-  byte temp[2];
 }
 
 // Private //
 
 // Write the required 16-bit value into the register
 void SBCDVA::_write_register(byte reg, int val) {
-  Wire.beginTransmission(Address);
-  Wire.write(reg);
-  Wire.write((val >> 8) & 0xFF);
-  Wire.write(val & 0xFF);
-  Wire.endTransmission();
+  wire->beginTransmission(Address);
+  wire->write(reg);
+  wire->write((val >> 8) & 0xFF);
+  wire->write(val & 0xFF);
+  wire->endTransmission();
+  // if (wire->endTransmission() != 0)  // bus error
+    // return BUS_ERROR;  // TODO: error handling? rely on read() error handling only?
 }
 
 // Read the 16-bit register value that will be returned
 int SBCDVA::_read_register(byte reg) {
-  Wire.beginTransmission(Address);
-  Wire.write(reg);
-  Wire.endTransmission();
-  Wire.requestFrom(Address, 2);
-  int value = (Wire.read() << 8) | Wire.read();
+  wire->beginTransmission(Address);
+  wire->write(reg);
+  // wire->endTransmission();
+  if (wire->endTransmission() != 0)  // bus error
+    return BUS_READ_ERROR;
+  // wire->requestFrom(Address, (uint8_t) 2);
+  if (wire->requestFrom(Address, (uint8_t) 2) == 0)  // size 0
+    return BUS_READ_ERROR;
+  int value = (wire->read() << 8) | wire->read();
   return value;
 }
 
 // Public //
 
 // Initialize the INA236 with the user specified parameters
-void SBCDVA::init_ina236(byte address, int mode, int vshct, int vbusct, int avg, int adcrange) {
+void SBCDVA::init_ina236(int mode, int vshct, int vbusct, int avg, int adcrange, uint8_t _address) {
+  if (_address != 0x0) Address = _address;  // use address set with constructor already, if not provided
+  _write_register(Config_Reg, RST);  // Reset the INA236 registers
   Mode = _MODE[mode];
   Vshct = _VSHCT[vshct];
   Vbusct = _VBUSCT[vbusct];
   Avg = _AVG[avg];
   Adcrange = _ADCRANGE[adcrange];
-  Address = _ADDRESS_A[address];
   Lsb = (Adcrange == ADCRANGE_1) ? _LSB[0] : _LSB[1];
   int config = 0x0000;
   config |= Mode;
@@ -66,14 +72,14 @@ void SBCDVA::init_ina236(byte address, int mode, int vshct, int vbusct, int avg,
 }
 
 // Reset the INA236 registers
-void SBCDVA::reset_ina236(byte address) {
-  Address = address;
+void SBCDVA::reset_ina236(byte _address) {
+  Address = _address;
   _write_register(Config_Reg, RST);
 }
 
 // Calibrate the INA236 for the correct Shunt measurement
 void SBCDVA::calibrate_ina236() {
-  float current_lsb_min = 10 / pow(2, 15);
+  static const float current_lsb_min = 10 / pow(2, 15);
   Current_lsb = current_lsb_min + 0.0018;
   int SHUNT_CAL = 0.00512 / (Current_lsb * 0.008);
   SHUNT_CAL = static_cast<int>(SHUNT_CAL);
@@ -108,33 +114,45 @@ float SBCDVA::read_bus_voltage() {
 }
 
 // Set the alert register
-void SBCDVA::mask_enable(byte val = 1) {
+void SBCDVA::mask_enable(byte val) {
+  if (val > sizeof(_MASK_ENABLE)) return;
   int out = _MASK_ENABLE[val];
   _write_register(Mask_Enable_Reg, out);
 }
 
 // Write a value into the alert register as reference
-void SBCDVA::write_alert_limit(int val = 0x294) {
+void SBCDVA::write_alert_limit(int val) {
   _write_register(Alert_Limit_Reg, val);
 }
 
-// Read the value from the alert register
-void SBCDVA::read_alert_limit() {
+// print the value from the alert register
+void SBCDVA::print_alert_limit(Stream* serial) {
+  if (serial == NULL) return;
   int raw = _read_register(Alert_Limit_Reg);
-  Serial.println("Mask/Alert register value: " + String(raw));
+  serial->print(F("Mask/Alert register value: "));
+  serial->println(String(raw));
 }
 
-// Read the Manufacturer ID
-void SBCDVA::manufacturer_ID() {
+// print the Manufacturer ID
+void SBCDVA::print_manufacturer_ID(Stream* serial) {
+  if (serial == NULL) return;
+  serial->print(F("Manufacturer ID: "));
   if (_read_register(Manufacturer_ID_Reg) == 21577) {
-    Serial.println("Manufacturer ID: TI");
+    serial->println(F("TI"));
   } else {
-    Serial.println("Manufacturer ID: nan");
+    serial->println(F("nan"));
   }
 }
 
+// print the Device ID
+void SBCDVA::print_device_ID(Stream* serial) {
+  if (serial == NULL) return;
+  serial->print(F("Device ID: "));
+  serial->println(String(_read_register(Device_ID_Reg)));
+}
+
 // Read the Device ID
-void SBCDVA::device_ID() {
-  Serial.print("Device ID: ");
-  Serial.println(String(_read_register(Device_ID_Reg)));
+int SBCDVA::read_device_ID() {
+  int value = _read_register(Device_ID_Reg);
+  return (value == BUS_READ_ERROR) ? 0 : value;
 }
diff --git a/SBC_DVA.h b/SBC_DVA.h
index 0e5dd74..055057c 100644
--- a/SBC_DVA.h
+++ b/SBC_DVA.h
@@ -9,6 +9,8 @@
 #ifndef sbcdva
 #define sbcdva
 
+static const int READING_INVALID = -1024;
+
 // Address variables ina236A
 const byte GND_A = 0x40;
 const byte VS_A = 0x41;
@@ -39,7 +41,7 @@ const int RST = 0x8000;
 // Range of the ADC
 const int ADCRANGE_1 = 0x0000;
 const int ADCRANGE_2 = 0x1000;
-
+ 
 // ADC values to be averaged
 const int AVG_1 = 0x0000;
 const int AVG_2 = 0x0200;
@@ -84,42 +86,47 @@ const int MODE_8 = 0x0007;
 #include <Wire.h>
 #include <math.h>
 
+
 class SBCDVA {
 public:
-  SBCDVA(uint8_t address);
-  void init_ina236(byte address, int mode, int vshct, int vbusct, int avg, int adcrange);
-  void reset_ina236(byte address);
+  SBCDVA(uint8_t _address, TwoWire* _wire = &Wire);
+  void init_ina236(int mode, int vshct, int vbusct, int avg, int adcrange, uint8_t _address = 0x0);
+  void reset_ina236(uint8_t _address);
   void calibrate_ina236();
   float read_current();
   float read_power();
   float read_shunt_voltage();
   float read_bus_voltage();
+  int read_device_ID();
   void mask_enable(byte val = 1);
   void write_alert_limit(int val = 0x294);
-  void read_alert_limit();
-  void manufacturer_ID();
-  void device_ID();
+  void print_alert_limit(Stream* serial = &Serial);
+  void print_manufacturer_ID(Stream* serial = &Serial);
+  void print_device_ID(Stream* serial = &Serial);
   float Current_lsb;
   float Lsb;
-  byte Address;
+  uint8_t Address;
   int Mode;
   int Vshct;
   int Vbusct;
   int Avg;
   int Adcrange;
-  byte temp[2];
+  
 private:
   void _write_register(byte reg, int val);
   int _read_register(byte reg);
-  int _ADDRESS_A[4] = { GND_A, VS_A, SDA_A, SCL_A };
-  int _ADDRESS_B[4] = { GND_B, VS_B, SDA_B, SCL_B };
-  int _ADCRANGE[2] = { ADCRANGE_1, ADCRANGE_2 };
-  float _LSB[3] = { 0.0000025, 0.000000625, 0.0016 };
-  int _AVG[8] = { AVG_1, AVG_2, AVG_3, AVG_4, AVG_5, AVG_6, AVG_7, AVG_8 };
-  int _VBUSCT[8] = { VBUSCT_1, VBUSCT_2, VBUSCT_3, VBUSCT_4, VBUSCT_5, VBUSCT_6, VBUSCT_7, VBUSCT_8 };
-  int _VSHCT[8] = { VSHCT_1, VSHCT_2, VSHCT_3, VSHCT_4, VSHCT_5, VSHCT_6, VSHCT_7, VSHCT_8 };
-  int _MODE[8] = { MODE_1, MODE_2, MODE_3, MODE_4, MODE_5, MODE_6, MODE_7, MODE_8 };
-  int _MASK_ENABLE[10] = { 0x8000, 0x4000, 0x2000, 0x1000, 0x0800, 0x0400, 0x0020, 0x0010, 0x0008, 0x0004 };
+  TwoWire* wire;
+  static constexpr int _ADDRESS_A[4] = { GND_A, VS_A, SDA_A, SCL_A };
+  static constexpr int _ADDRESS_B[4] = { GND_B, VS_B, SDA_B, SCL_B };
+  static constexpr int _ADCRANGE[2] = { ADCRANGE_1, ADCRANGE_2 };
+  static constexpr float _LSB[3] = { 0.0000025, 0.000000625, 0.0016 };
+  static constexpr int _AVG[8] = { AVG_1, AVG_2, AVG_3, AVG_4, AVG_5, AVG_6, AVG_7, AVG_8 };
+  static constexpr int _VBUSCT[8] = { VBUSCT_1, VBUSCT_2, VBUSCT_3, VBUSCT_4, VBUSCT_5, VBUSCT_6, VBUSCT_7, VBUSCT_8 };
+  static constexpr int _VSHCT[8] = { VSHCT_1, VSHCT_2, VSHCT_3, VSHCT_4, VSHCT_5, VSHCT_6, VSHCT_7, VSHCT_8 };
+  static constexpr int _MODE[8] = { MODE_1, MODE_2, MODE_3, MODE_4, MODE_5, MODE_6, MODE_7, MODE_8 };
+  static constexpr unsigned int _MASK_ENABLE[10] = { 0x8000, 0x4000, 0x2000, 0x1000, 0x0800, 0x0400, 0x0020, 0x0010, 0x0008, 0x0004 };
+  
+  static const int BUS_READ_ERROR = 0;//0x8000;
 };
 
 #endif
\ No newline at end of file
diff --git a/examples/SBC-DVA-Example/SBC-DVA-Example.ino b/examples/SBC-DVA-Example/SBC-DVA-Example.ino
index 63da2f6..927b81a 100644
--- a/examples/SBC-DVA-Example/SBC-DVA-Example.ino
+++ b/examples/SBC-DVA-Example/SBC-DVA-Example.ino
@@ -14,9 +14,9 @@ void setup() {
   INA236.calibrate_ina236();
   INA236.mask_enable(1);
   INA236.write_alert_limit();
-  INA236.read_alert_limit();
-  INA236.manufacturer_ID();
-  INA236.device_ID();
+  INA236.print_alert_limit();
+  INA236.print_manufacturer_ID();
+  INA236.print_device_ID();
   delay(5000);  // Sleep for 5 seconds
   Serial.println("start");
 }