diff --git a/IODevice.cpp b/IODevice.cpp
index be26b92..32e6445 100644
--- a/IODevice.cpp
+++ b/IODevice.cpp
@@ -74,6 +74,13 @@ void IODevice::begin() {
   MCP23017::create(180, 16, 0x21);
 }
 
+// reset() function to reinitialise all devices
+void IODevice::reset() {
+  for (IODevice *dev = _firstDevice; dev != NULL; dev = dev->_nextDevice) {
+    dev->_begin();
+  }
+}
+
 // Overarching static loop() method for the IODevice subsystem.  Works through the
 // list of installed devices and calls their individual _loop() method.
 // Devices may or may not implement this, but if they do it is useful for things like animations 
@@ -302,9 +309,9 @@ IODevice *IODevice::findDeviceFollowing(VPIN vpin) {
 
 // Private helper function to check for vpin overlap. Run during setup only.
 // returns true if pins DONT overlap with existing device
-bool IODevice::checkNoOverlap(VPIN firstPin, uint8_t nPins, uint8_t i2cAddress) {
+bool IODevice::checkNoOverlap(VPIN firstPin, uint8_t nPins, I2CAddress i2cAddress) {
 #ifdef DIAG_IO
-  DIAG(F("Check no overlap %d %d 0x%x"), firstPin,nPins,i2cAddress);
+  DIAG(F("Check no overlap %d %d %s"), firstPin,nPins,i2cAddress.toString());
 #endif
   VPIN lastPin=firstPin+nPins-1;
   for (IODevice *dev = _firstDevice; dev != 0; dev = dev->_nextDevice) {
@@ -322,7 +329,7 @@ bool IODevice::checkNoOverlap(VPIN firstPin, uint8_t nPins, uint8_t i2cAddress)
     }
     // Check for overlapping I2C address
     if (i2cAddress && dev->_I2CAddress==i2cAddress) {
-      DIAG(F("WARNING HAL Overlap. i2c Addr 0x%x ignored."),(int)i2cAddress);
+      DIAG(F("WARNING HAL Overlap. i2c Addr %s ignored."),i2cAddress.toString());
       return false;
     } 
   }
diff --git a/IODevice.h b/IODevice.h
index f5c7c6f..8fd5efd 100644
--- a/IODevice.h
+++ b/IODevice.h
@@ -113,6 +113,10 @@ public:
   // Also, the _begin method of any existing instances is called from here.
   static void begin();
 
+  // reset function to invoke all driver's _begin() methods again, to
+  // reset the state of the devices and reinitialise.
+  static void reset();
+
   // configure is used invoke an IODevice instance's _configure method
   static bool configure(VPIN vpin, ConfigTypeEnum configType, int paramCount, int params[]);
 
@@ -165,7 +169,7 @@ public:
   void setGPIOInterruptPin(int16_t pinNumber);
 
   // Method to check if pins will overlap before creating new device. 
-  static bool checkNoOverlap(VPIN firstPin, uint8_t nPins=1, uint8_t i2cAddress=0);
+  static bool checkNoOverlap(VPIN firstPin, uint8_t nPins=1, I2CAddress i2cAddress=0);
 
   // Method used by IODevice filters to locate slave pins that may be overlayed by their own
   // pin range.  
diff --git a/IO_AnalogueInputs.h b/IO_AnalogueInputs.h
index a03d90f..8ff8683 100644
--- a/IO_AnalogueInputs.h
+++ b/IO_AnalogueInputs.h
@@ -85,7 +85,7 @@ private:
       _display();
 #endif
     } else {
-      DIAG(F("ADS111x device not found, I2C:%x"), (int)_I2CAddress);
+      DIAG(F("ADS111x device not found, I2C:%s"), _I2CAddress.toString());
       _deviceState = DEVSTATE_FAILED;
     }
   }
@@ -131,7 +131,7 @@ private:
           break;
       }
     } else { // error status
-      DIAG(F("ADS111x I2C:x%x Error:%d %S"), (int)_I2CAddress, status, I2CManager.getErrorMessage(status));
+      DIAG(F("ADS111x I2C:%s Error:%d %S"), _I2CAddress.toString(), status, I2CManager.getErrorMessage(status));
       _deviceState = DEVSTATE_FAILED;
     }
   }
@@ -142,7 +142,7 @@ private:
   }
   
   void _display() override {
-    DIAG(F("ADS111x I2C:x%x Configured on Vpins:%d-%d %S"), (int)_I2CAddress, _firstVpin, _firstVpin+_nPins-1,
+    DIAG(F("ADS111x I2C:%s Configured on Vpins:%d-%d %S"), _I2CAddress.toString(), _firstVpin, _firstVpin+_nPins-1,
       _deviceState == DEVSTATE_FAILED ? F("OFFLINE") : F(""));
   }
 
diff --git a/IO_EXFastclock.h b/IO_EXFastclock.h
index 0e1bf76..442799b 100644
--- a/IO_EXFastclock.h
+++ b/IO_EXFastclock.h
@@ -56,7 +56,7 @@ static void create(uint8_t _I2CAddress) {
   // XXXX change thistosave2 bytes
   if (_checkforclock == 0) {
       FAST_CLOCK_EXISTS = true;
-      //DIAG(F("I2C Fast Clock found at x%x"), _I2CAddress);
+      //DIAG(F("I2C Fast Clock found at %s"), _I2CAddress.toString());
       new EXFastClock(_I2CAddress); 
     }
     else {
@@ -68,7 +68,6 @@ static void create(uint8_t _I2CAddress) {
   }
     
 private:
-uint8_t _I2CAddress;
   
 
 // Initialisation of Fastclock
@@ -84,7 +83,7 @@ void _begin() override {
     } else {
     _deviceState = DEVSTATE_FAILED;
     //LCD(6,F("CLOCK NOT FOUND")); 
-    DIAG(F("Fast Clock Not Found at address %d"), _I2CAddress);
+    DIAG(F("Fast Clock Not Found at address %s"), _I2CAddress.toString());
     }
   }
 }
@@ -120,7 +119,7 @@ void _loop(unsigned long currentMicros) override{
 
   // Display EX-FastClock device driver info.
   void _display() {
-    DIAG(F("FastCLock on I2C:x%x - %S"), _I2CAddress,  (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
+    DIAG(F("FastCLock on I2C:%s - %S"), _I2CAddress.toString(),  (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
   }
   
 };
diff --git a/IO_EXIOExpander.h b/IO_EXIOExpander.h
index d2269f6..06cbc24 100644
--- a/IO_EXIOExpander.h
+++ b/IO_EXIOExpander.h
@@ -63,7 +63,7 @@ private:
   EXIOExpander(VPIN firstVpin, int nPins, I2CAddress i2cAddress, int numDigitalPins, int numAnaloguePins) {
     _firstVpin = firstVpin;
     _nPins = nPins;
-    _i2cAddress = i2cAddress;
+    _I2CAddress = i2cAddress;
     _numDigitalPins = numDigitalPins;
     _numAnaloguePins = numAnaloguePins;
     _digitalPinBytes = (numDigitalPins+7)/8;
@@ -76,31 +76,31 @@ private:
   void _begin() {
     // Initialise EX-IOExander device
     I2CManager.begin();
-    if (I2CManager.exists(_i2cAddress)) {
+    if (I2CManager.exists(_I2CAddress)) {
       _digitalOutBuffer[0] = EXIOINIT;
       _digitalOutBuffer[1] = _numDigitalPins;
       _digitalOutBuffer[2] = _numAnaloguePins;
       // Send config, if EXIORDY returned, we're good, otherwise go offline
-      I2CManager.read(_i2cAddress, _commandBuffer, 1, _digitalOutBuffer, 3);
+      I2CManager.read(_I2CAddress, _commandBuffer, 1, _digitalOutBuffer, 3);
       if (_commandBuffer[0] != EXIORDY) {
-        DIAG(F("ERROR configuring EX-IOExpander device, I2C:x%x"), (int)_i2cAddress);
+        DIAG(F("ERROR configuring EX-IOExpander device, I2C:%s"), _I2CAddress.toString());
         _deviceState = DEVSTATE_FAILED;
         return;
       }
       // Attempt to get version, if we don't get it, we don't care, don't go offline
       // Using digital in buffer in reverse to save RAM
       _commandBuffer[0] = EXIOVER;
-      I2CManager.read(_i2cAddress, _versionBuffer, 3, _commandBuffer, 1);
+      I2CManager.read(_I2CAddress, _versionBuffer, 3, _commandBuffer, 1);
       _majorVer = _versionBuffer[0];
       _minorVer = _versionBuffer[1];
       _patchVer = _versionBuffer[2];
-      DIAG(F("EX-IOExpander device found, I2C:x%x, Version v%d.%d.%d"),
-          (int)_i2cAddress, _versionBuffer[0], _versionBuffer[1], _versionBuffer[2]);
+      DIAG(F("EX-IOExpander device found, I2C:%s, Version v%d.%d.%d"),
+          _I2CAddress.toString(), _versionBuffer[0], _versionBuffer[1], _versionBuffer[2]);
 #ifdef DIAG_IO
       _display();
 #endif
     } else {
-      DIAG(F("EX-IOExpander device not found, I2C:x%x"), (int)_i2cAddress);
+      DIAG(F("EX-IOExpander device not found, I2C:%s"), _I2CAddress.toString());
       _deviceState = DEVSTATE_FAILED;
     }
   }
@@ -117,7 +117,7 @@ private:
     _digitalOutBuffer[0] = EXIODPUP;
     _digitalOutBuffer[1] = pin;
     _digitalOutBuffer[2] = pullup;
-    I2CManager.write(_i2cAddress, _digitalOutBuffer, 3);
+    I2CManager.write(_I2CAddress, _digitalOutBuffer, 3);
     return true;
   }
 
@@ -130,16 +130,16 @@ private:
     int pin = vpin - _firstVpin;
     _analogueOutBuffer[0] = EXIOENAN;
     _analogueOutBuffer[1] = pin;
-    I2CManager.write(_i2cAddress, _analogueOutBuffer, 2);
+    I2CManager.write(_I2CAddress, _analogueOutBuffer, 2);
     return true;
   }
 
   void _loop(unsigned long currentMicros) override {
     (void)currentMicros; // remove warning
     _commandBuffer[0] = EXIORDD;
-    I2CManager.read(_i2cAddress, _digitalInputStates, _digitalPinBytes, _commandBuffer, 1);
+    I2CManager.read(_I2CAddress, _digitalInputStates, _digitalPinBytes, _commandBuffer, 1);
     _commandBuffer[0] = EXIORDAN;
-    I2CManager.read(_i2cAddress, _analogueInputStates, _analoguePinBytes, _commandBuffer, 1);
+    I2CManager.read(_I2CAddress, _analogueInputStates, _analoguePinBytes, _commandBuffer, 1);
   }
 
   int _readAnalogue(VPIN vpin) override {
@@ -164,7 +164,7 @@ private:
     _digitalOutBuffer[0] = EXIOWRD;
     _digitalOutBuffer[1] = pin;
     _digitalOutBuffer[2] = value;
-    I2CManager.write(_i2cAddress, _digitalOutBuffer, 3);
+    I2CManager.write(_I2CAddress, _digitalOutBuffer, 3);
   }
 
   void _display() override {
@@ -176,14 +176,13 @@ private:
       _firstAnalogue = _firstVpin + _numDigitalPins;
       _lastAnalogue = _firstVpin + _nPins - 1;
     }
-    DIAG(F("EX-IOExpander I2C:x%x v%d.%d.%d: %d Digital Vpins %d-%d, %d Analogue Vpins %d-%d %S"),
-              (int)_i2cAddress, _majorVer, _minorVer, _patchVer,
+    DIAG(F("EX-IOExpander I2C:%s v%d.%d.%d: %d Digital Vpins %d-%d, %d Analogue Vpins %d-%d %S"),
+              _I2CAddress.toString(), _majorVer, _minorVer, _patchVer,
               _numDigitalPins, _firstVpin, _firstVpin + _numDigitalPins - 1,
               _numAnaloguePins, _firstAnalogue, _lastAnalogue,
               _deviceState == DEVSTATE_FAILED ? F("OFFLINE") : F(""));
   }
 
-  uint8_t _i2cAddress;
   uint8_t _numDigitalPins;
   uint8_t _numAnaloguePins;
   byte _analogueOutBuffer[2];
diff --git a/IO_EXTurntable.h b/IO_EXTurntable.h
index 5b501b3..02a87e3 100644
--- a/IO_EXTurntable.h
+++ b/IO_EXTurntable.h
@@ -106,15 +106,15 @@ void EXTurntable::_writeAnalogue(VPIN vpin, int value, uint8_t activity, uint16_
   DIAG(F("EX-Turntable WriteAnalogue Vpin:%d Value:%d Activity:%d Duration:%d"),
     vpin, value, activity, duration);
   DIAG(F("I2CManager write I2C Address:%d stepsMSB:%d stepsLSB:%d activity:%d"),
-    (int)_I2CAddress, stepsMSB, stepsLSB, activity);
+    _I2CAddress.toString(), stepsMSB, stepsLSB, activity);
 #endif
   _stepperStatus = 1;     // Tell the device driver Turntable-EX is busy
-  I2CManager.write((int)_I2CAddress, 3, stepsMSB, stepsLSB, activity);
+  I2CManager.write(_I2CAddress, 3, stepsMSB, stepsLSB, activity);
 }
 
 // Display Turnetable-EX device driver info.
 void EXTurntable::_display() {
-  DIAG(F("EX-Turntable I2C:x%x Configured on Vpins:%d-%d %S"), (int)_I2CAddress, (int)_firstVpin, 
+  DIAG(F("EX-Turntable I2C:%s Configured on Vpins:%d-%d %S"), _I2CAddress.toString(), (int)_firstVpin, 
     (int)_firstVpin+_nPins-1, (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
 }
 
diff --git a/IO_GPIOBase.h b/IO_GPIOBase.h
index 17e72d6..0f7019c 100644
--- a/IO_GPIOBase.h
+++ b/IO_GPIOBase.h
@@ -107,7 +107,7 @@ void GPIOBase<T>::_begin() {
     _setupDevice();
     _deviceState = DEVSTATE_NORMAL;
   } else {
-    DIAG(F("%S I2C:x%x Device not detected"), _deviceName, (int)_I2CAddress);
+    DIAG(F("%S I2C:%s Device not detected"), _deviceName, _I2CAddress.toString());
     _deviceState = DEVSTATE_FAILED;
   }
 }
@@ -121,7 +121,7 @@ bool GPIOBase<T>::_configure(VPIN vpin, ConfigTypeEnum configType, int paramCoun
   bool pullup = params[0];
   int pin = vpin - _firstVpin;
   #ifdef DIAG_IO
-  DIAG(F("%S I2C:x%x Config Pin:%d Val:%d"), _deviceName, (int)_I2CAddress, pin, pullup);
+  DIAG(F("%S I2C:%s Config Pin:%d Val:%d"), _deviceName, _I2CAddress.toString(), pin, pullup);
   #endif
   uint16_t mask = 1 << pin;
   if (pullup) 
@@ -151,7 +151,7 @@ void GPIOBase<T>::_loop(unsigned long currentMicros) {
       _deviceState = DEVSTATE_NORMAL;
     } else {
       _deviceState = DEVSTATE_FAILED;
-      DIAG(F("%S I2C:x%x Error:%d %S"), _deviceName, (int)_I2CAddress, status, 
+      DIAG(F("%S I2C:%s Error:%d %S"), _deviceName, _I2CAddress.toString(), status, 
         I2CManager.getErrorMessage(status));
     }
     _processCompletion(status);
@@ -174,7 +174,7 @@ void GPIOBase<T>::_loop(unsigned long currentMicros) {
 
     #ifdef DIAG_IO
     if (differences)
-      DIAG(F("%S I2C:x%x PortStates:%x"), _deviceName, (int)_I2CAddress, _portInputState);
+      DIAG(F("%S I2C:%s PortStates:%x"), _deviceName, _I2CAddress.toString(), _portInputState);
     #endif
   }
 
@@ -195,7 +195,7 @@ void GPIOBase<T>::_loop(unsigned long currentMicros) {
 
 template <class T>
 void GPIOBase<T>::_display() {
-  DIAG(F("%S I2C:x%x Configured on Vpins:%d-%d %S"), _deviceName, (int)_I2CAddress, 
+  DIAG(F("%S I2C:%s Configured on Vpins:%d-%d %S"), _deviceName, _I2CAddress.toString(), 
     _firstVpin, _firstVpin+_nPins-1, (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
 }
 
@@ -204,7 +204,7 @@ void GPIOBase<T>::_write(VPIN vpin, int value) {
   int pin = vpin - _firstVpin;
   T mask = 1 << pin;
   #ifdef DIAG_IO
-  DIAG(F("%S I2C:x%x Write Pin:%d Val:%d"), _deviceName, (int)_I2CAddress, pin, value);
+  DIAG(F("%S I2C:%s Write Pin:%d Val:%d"), _deviceName, _I2CAddress.toString(), pin, value);
   #endif
 
   // Set port mode output if currently not output mode
@@ -240,7 +240,7 @@ int GPIOBase<T>::_read(VPIN vpin) {
   // Set unused pin and write mode pin value to 1
     _portInputState |= ~_portInUse | _portMode;
     #ifdef DIAG_IO
-    DIAG(F("%S I2C:x%x PortStates:%x"), _deviceName, (int)_I2CAddress, _portInputState);
+    DIAG(F("%S I2C:%s PortStates:%x"), _deviceName, _I2CAddress.toString(), _portInputState);
     #endif
   }
   return (_portInputState & mask) ? 0 : 1;  // Invert state (5v=0, 0v=1)
diff --git a/IO_OLEDDisplay.h b/IO_OLEDDisplay.h
index 9aefbaa..1ef8ed1 100644
--- a/IO_OLEDDisplay.h
+++ b/IO_OLEDDisplay.h
@@ -86,32 +86,38 @@ protected:
     _buffer = (char *)calloc(_numRows*_numCols, sizeof(char));
     _rowGeneration = (uint8_t *)calloc(_numRows, sizeof(uint8_t));
     _lastRowGeneration = (uint8_t *)calloc(_numRows, sizeof(uint8_t));
+    // Fill buffer with spaces
+    memset(_buffer, ' ', _numCols*_numRows);
+
+    // Create OLED driver
+    oled = new SSD1306AsciiWire();
+
+    // Clear the entire screen
+    oled->clearNative();
     
     addDevice(this);
   }
-
+  
   // Device-specific initialisation
   void _begin() override {
-    // Create OLED driver
-    oled = new SSD1306AsciiWire();
     // Initialise device
     if (oled->begin(_I2CAddress, _width, _height)) {
       // Store pointer to this object into CS display hook, so that we
       // will intercept any subsequent calls to lcdDisplay methods.
       DisplayInterface::lcdDisplay = this;
 
-      DIAG(F("OLEDDisplay installed on address x%x"), (int)_I2CAddress);
-
-      // First clear the entire screen
-      oled->clearNative();
+      DIAG(F("OLEDDisplay installed on address %s"), _I2CAddress.toString());
 
       // Set first two lines on screen
       LCD(0,F("DCC++ EX v%S"),F(VERSION));
       LCD(1,F("Lic GPLv3"));
+
+      // Force all rows to be redrawn
+      for (uint8_t row=0; row<_numRows; row++)
+        _rowGeneration[row]++;
     }
   }
 
-  
   void _loop(unsigned long) override {
 
     // Loop through the buffer and if a row has changed
@@ -196,7 +202,7 @@ protected:
 
   // Display information about the device.
   void _display() {
-    DIAG(F("OLEDDisplay Configured addr x%x"), (int)_I2CAddress);
+    DIAG(F("OLEDDisplay Configured addr %s"), _I2CAddress.toString());
   }
 
 };
diff --git a/IO_PCA9685.cpp b/IO_PCA9685.cpp
index f7a6882..68e44a1 100644
--- a/IO_PCA9685.cpp
+++ b/IO_PCA9685.cpp
@@ -239,13 +239,13 @@ void PCA9685::updatePosition(uint8_t pin) {
 // between 0 and 4095 for the PWM mark-to-period ratio, with 4095 being 100%.
 void PCA9685::writeDevice(uint8_t pin, int value) {
   #ifdef DIAG_IO
-  DIAG(F("PCA9685 I2C:x%x WriteDevice Pin:%d Value:%d"), (int)_I2CAddress, pin, value);
+  DIAG(F("PCA9685 I2C:%s WriteDevice Pin:%d Value:%d"), _I2CAddress.toString(), pin, value);
   #endif
   // Wait for previous request to complete
   uint8_t status = requestBlock.wait();
   if (status != I2C_STATUS_OK) {
     _deviceState = DEVSTATE_FAILED;
-    DIAG(F("PCA9685 I2C:x%x failed %S"), (int)_I2CAddress, I2CManager.getErrorMessage(status));
+    DIAG(F("PCA9685 I2C:%s failed %S"), _I2CAddress.toString(), I2CManager.getErrorMessage(status));
   } else {
     // Set up new request.
     outputBuffer[0] = PCA9685_FIRST_SERVO + 4 * pin;
@@ -259,7 +259,7 @@ void PCA9685::writeDevice(uint8_t pin, int value) {
 
 // Display details of this device.
 void PCA9685::_display() {
-  DIAG(F("PCA9685 I2C:x%x Configured on Vpins:%d-%d %S"), (int)_I2CAddress, (int)_firstVpin, 
+  DIAG(F("PCA9685 I2C:%s Configured on Vpins:%d-%d %S"), _I2CAddress.toString(), (int)_firstVpin, 
     (int)_firstVpin+_nPins-1, (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
 }
 
diff --git a/IO_PCA9685pwm.h b/IO_PCA9685pwm.h
index 72884a9..ef92118 100644
--- a/IO_PCA9685pwm.h
+++ b/IO_PCA9685pwm.h
@@ -101,8 +101,8 @@ private:
   void _writeAnalogue(VPIN vpin, int value, uint8_t param1, uint16_t param2) override {
     (void)param1; (void)param2;  // suppress compiler warning
     #ifdef DIAG_IO
-    DIAG(F("PCA9685pwm WriteAnalogue Vpin:%d Value:%d Profile:%d Duration:%d %S"), 
-      vpin, value, profile, duration, _deviceState == DEVSTATE_FAILED?F("DEVSTATE_FAILED"):F(""));
+    DIAG(F("PCA9685pwm WriteAnalogue Vpin:%d Value:%d %S"), 
+      vpin, value, _deviceState == DEVSTATE_FAILED?F("DEVSTATE_FAILED"):F(""));
     #endif
     if (_deviceState == DEVSTATE_FAILED) return;
     int pin = vpin - _firstVpin;
@@ -114,7 +114,7 @@ private:
 
   // Display details of this device.
   void _display() override {
-    DIAG(F("PCA9685pwm I2C:x%x Configured on Vpins:%d-%d %S"), (int)_I2CAddress, (int)_firstVpin, 
+    DIAG(F("PCA9685pwm I2C:%s Configured on Vpins:%d-%d %S"), _I2CAddress.toString(), (int)_firstVpin, 
       (int)_firstVpin+_nPins-1, (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
   }
 
@@ -122,13 +122,13 @@ private:
   // between 0 and 4095 for the PWM mark-to-period ratio, with 4095 being 100%.
   void writeDevice(uint8_t pin, int value) {
     #ifdef DIAG_IO
-    DIAG(F("PCA9685pwm I2C:x%x WriteDevice Pin:%d Value:%d"), (int)_I2CAddress, pin, value);
+    DIAG(F("PCA9685pwm I2C:%s WriteDevice Pin:%d Value:%d"), _I2CAddress.toString(), pin, value);
     #endif
     // Wait for previous request to complete
     uint8_t status = requestBlock.wait();
     if (status != I2C_STATUS_OK) {
       _deviceState = DEVSTATE_FAILED;
-      DIAG(F("PCA9685pwm I2C:x%x failed %S"), (int)_I2CAddress, I2CManager.getErrorMessage(status));
+      DIAG(F("PCA9685pwm I2C:%s failed %S"), _I2CAddress.toString(), I2CManager.getErrorMessage(status));
     } else {
       // Set up new request.
       outputBuffer[0] = PCA9685_FIRST_SERVO + 4 * pin;
diff --git a/IO_RotaryEncoder.h b/IO_RotaryEncoder.h
index 6de97af..9cf4e65 100644
--- a/IO_RotaryEncoder.h
+++ b/IO_RotaryEncoder.h
@@ -104,7 +104,7 @@ private:
   }
   
   void _display() override {
-    DIAG(F("Rotary Encoder I2C:x%x v%d.%d.%d Configured on Vpin:%d-%d %S"), (int)_I2CAddress, _majorVer, _minorVer, _patchVer,
+    DIAG(F("Rotary Encoder I2C:%s v%d.%d.%d Configured on Vpin:%d-%d %S"), _I2CAddress.toString(), _majorVer, _minorVer, _patchVer,
       (int)_firstVpin, _firstVpin+_nPins-1, (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
   }
 
diff --git a/IO_VL53L0X.h b/IO_VL53L0X.h
index 86d9624..a1e1dcc 100644
--- a/IO_VL53L0X.h
+++ b/IO_VL53L0X.h
@@ -159,7 +159,9 @@ protected:
     if (_xshutPin == VPIN_NONE && I2CManager.exists(_I2CAddress)) {
       // Device already present on this address, so skip the address initialisation.
       _nextState = STATE_CONFIGUREDEVICE;
-    }
+    } else
+      _nextState = STATE_INIT;
+
   }
 
   void _loop(unsigned long currentMicros) override {
@@ -171,7 +173,7 @@ protected:
         // If no XSHUT pin is configured, then only one device is supported.
         if (_xshutPin != VPIN_NONE) IODevice::write(_xshutPin, 0);
         _nextState = STATE_RESTARTMODULE;
-        delayUntil(currentMicros+1000);
+        delayUntil(currentMicros+10000);
         break;
       case STATE_RESTARTMODULE:
         // On second entry, set XSHUT pin high to allow this module to restart.
@@ -183,9 +185,8 @@ protected:
         // shared flag accessible to all device instances.
         if (_addressConfigInProgress) return;
         _addressConfigInProgress = true;
-        // Set XSHUT pin (if connected).  Because of supply voltage differences,
-        // drive the signal through the digital output's pull-up resistor.
-        if (_xshutPin != VPIN_NONE) IODevice::configureInput(_xshutPin, 1);
+        // Set XSHUT pin (if connected) to bring the module out of sleep mode.
+        if (_xshutPin != VPIN_NONE) IODevice::write(_xshutPin, 1);
         // Allow the module time to restart
         delayUntil(currentMicros+10000);
         _nextState = STATE_CONFIGUREADDRESS;
@@ -202,15 +203,12 @@ protected:
           I2CManager.write(VL53L0X_I2C_DEFAULT_ADDRESS, 2, VL53L0X_REG_I2C_SLAVE_DEVICE_ADDRESS, _I2CAddress);
           #endif
         }
-        _addressConfigInProgress = false;
-        _nextState = STATE_SKIP;
-        break;
-      case STATE_SKIP:
-        // Do nothing on the third entry.
-        _nextState = STATE_CONFIGUREDEVICE;
+        delayUntil(currentMicros+10000);
         break;
       case STATE_CONFIGUREDEVICE:
-        // On next entry, check if device address has been set.
+        // Allow next VL53L0X device to be configured
+        _addressConfigInProgress = false;
+        // Now check if device address has been set.
         if (I2CManager.exists(_I2CAddress)) {
           #ifdef DIAG_IO
           _display();
@@ -220,7 +218,7 @@ protected:
             read_reg(VL53L0X_CONFIG_PAD_SCL_SDA__EXTSUP_HV) | 0x01);
           _nextState = STATE_INITIATESCAN;
         } else {
-          DIAG(F("VL53L0X I2C:x%x device not responding"), (int)_I2CAddress);
+          DIAG(F("VL53L0X I2C:%s device not responding"), _I2CAddress.toString());
           _deviceState = DEVSTATE_FAILED;
           _nextState = STATE_FAILED;
         }
@@ -285,7 +283,7 @@ protected:
 
   // Function to report a failed I2C operation.  Put the device off-line.
   void reportError(uint8_t status) {
-    DIAG(F("VL53L0X I2C:x%x Error:%d %S"), (int)_I2CAddress, status, I2CManager.getErrorMessage(status));
+    DIAG(F("VL53L0X I2C:%s Error:%d %S"), _I2CAddress.toString(), status, I2CManager.getErrorMessage(status));
     _deviceState = DEVSTATE_FAILED;
     _value = false;
   }
@@ -314,8 +312,8 @@ protected:
   }
 
   void _display() override {
-    DIAG(F("VL53L0X I2C:x%x Configured on Vpins:%d-%d On:%dmm Off:%dmm %S"),
-      (int)_I2CAddress, _firstVpin, _firstVpin+_nPins-1, _onThreshold, _offThreshold,
+    DIAG(F("VL53L0X I2C:%s Configured on Vpins:%d-%d On:%dmm Off:%dmm %S"),
+      _I2CAddress.toString(), _firstVpin, _firstVpin+_nPins-1, _onThreshold, _offThreshold,
       (_deviceState==DEVSTATE_FAILED) ? F("OFFLINE") : F(""));
   }
   
diff --git a/LiquidCrystal_I2C.cpp b/LiquidCrystal_I2C.cpp
index b18614f..a5c2e16 100644
--- a/LiquidCrystal_I2C.cpp
+++ b/LiquidCrystal_I2C.cpp
@@ -53,7 +53,7 @@ LiquidCrystal_I2C::LiquidCrystal_I2C(I2CAddress lcd_Addr, uint8_t lcd_cols,
   I2CManager.setClock(100000L);    // PCF8574 is spec'd to 100kHz.
 
   if (I2CManager.exists(lcd_Addr)) {
-    DIAG(F("%dx%d LCD configured on I2C:x%x"), (int)lcd_cols, (int)lcd_rows, (int)lcd_Addr);
+    DIAG(F("%dx%d LCD configured on I2C:%s"), (int)lcd_cols, (int)lcd_rows, (int)lcd_Addr);
     _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
     begin();
     backlight();
diff --git a/SSD1306Ascii.cpp b/SSD1306Ascii.cpp
index 12d8702..deae5ac 100644
--- a/SSD1306Ascii.cpp
+++ b/SSD1306Ascii.cpp
@@ -197,7 +197,7 @@ bool SSD1306AsciiWire::begin(I2CAddress address, int width, int height) {
     return false;
   }
   // Device found
-  DIAG(F("%dx%d OLED display configured on I2C:x%x"), m_displayWidth, m_displayHeight, (int)m_i2cAddr);
+  DIAG(F("%dx%d OLED display configured on I2C:%s"), m_displayWidth, m_displayHeight, m_i2cAddr.toString());
   clear();
   return true;
 }