diff --git a/Arduino/BTCDieselHeater/src/OLED/GPIOScreen.cpp b/Arduino/BTCDieselHeater/src/OLED/GPIOScreen.cpp
new file mode 100644
index 0000000..df0043b
--- /dev/null
+++ b/Arduino/BTCDieselHeater/src/OLED/GPIOScreen.cpp
@@ -0,0 +1,298 @@
+/*
+ * This file is part of the "bluetoothheater" distribution 
+ * (https://gitlab.com/mrjones.id.au/bluetoothheater) 
+ *
+ * Copyright (C) 2018  Ray Jones <ray@mrjones.id.au>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ * 
+ */
+
+#include "128x64OLED.h"
+#include "GPIOScreen.h"
+#include "KeyPad.h"
+#include "../Protocol/helpers.h"
+#include "../Utility/UtilClasses.h"
+#include "../Utility/NVStorage.h"
+#include "../Utility/GPIO.h"
+
+extern CGPIOout GPIOout;
+extern CGPIOin GPIOin;
+
+///////////////////////////////////////////////////////////////////////////
+//
+// CGPIOScreen
+//
+// This screen provides control over GPIO features
+//
+///////////////////////////////////////////////////////////////////////////
+
+static const int Line3 = 14;
+static const int Line2 = 27;
+static const int Line1 = 40;
+static const int Column = 58;
+
+CGPIOScreen::CGPIOScreen(C128x64_OLED& display, CScreenManager& mgr) : CPasswordScreen(display, mgr) 
+{
+  _initUI();
+  _GPIOinMode = 0;
+  _GPIOoutMode = 0;
+  _GPIOalgMode = 0;
+}
+
+void 
+CGPIOScreen::onSelect()
+{
+  CPasswordScreen::onSelect();
+  _initUI();
+  _GPIOinMode = NVstore.getGPIOinMode();
+  _GPIOoutMode = NVstore.getGPIOoutMode();
+  _GPIOalgMode = NVstore.getGPIOalgMode();
+}
+
+void
+CGPIOScreen::_initUI()
+{
+  _rowSel = 0;
+  _animateCount = 0;
+}
+
+bool 
+CGPIOScreen::show()
+{
+  _display.clearDisplay();
+
+  if(!CPasswordScreen::show()) {  // for showing "saving settings"
+
+    if(_rowSel == 4) {
+      _printInverted(_display.xCentre(), 0, " Saving Settings ", true, eCentreJustify);
+      _printMenuText(_display.xCentre(), 35, "Press UP to", false, eCentreJustify);
+      _printMenuText(_display.xCentre(), 43, "confirm save", false, eCentreJustify);
+    }
+    else {
+      _printInverted(_display.xCentre(), 0, " GPIO Settings ", true, eCentreJustify);
+      _printMenuText(55, Line3, "Inputs:", false, eRightJustify);
+      _printMenuText(55, Line2, "Outputs:", false, eRightJustify);
+      _printMenuText(55, Line1, "Analogue:", false, eRightJustify);
+      switch(_GPIOinMode) {
+        case 0:
+          _printMenuText(Column, Line3, "Disabled", _rowSel == 3);
+          break;
+        case 1: 
+          _printMenuText(Column, Line3, "1-On 2-Off", _rowSel == 3);
+          break;
+        case 2: 
+          _printMenuText(Column, Line3, "1-On 2-\352T", _rowSel == 3);
+          break;
+        case 3: 
+          _printMenuText(Column, Line3, "1-On/Off", _rowSel == 3);
+          break;
+      }
+      switch(_GPIOoutMode) {
+        case 0:
+          _printMenuText(Column, Line2, "Disabled", _rowSel == 2);
+          break;
+        case 1:
+          _printMenuText(Column, Line2, "1:LED", _rowSel == 2);
+          break;
+        case 2:
+          _printMenuText(Column, Line2, "1&2:User", _rowSel == 2);
+          break;
+      }
+      switch(_GPIOalgMode) {
+        case 0:
+          _printMenuText(Column, Line1, "Disabled", _rowSel == 1);
+          break;
+        case 1:
+          _printMenuText(Column, Line1, "Ip1 allows", _rowSel == 1);
+          break;
+      }
+    }
+  }
+
+  return true;
+}
+
+bool 
+CGPIOScreen::animate()
+{
+  if(_rowSel != 4) {
+    int yPos = 53;
+    int xPos = _display.xCentre();
+    const char* pMsg = NULL;
+    switch(_rowSel) {
+      case 0:
+        _printMenuText(xPos, yPos, " \021  \030Edit  Exit   \020 ", true, eCentreJustify);
+        break;
+      case 1:
+        _display.drawFastHLine(0, 52, 128, WHITE);
+        switch(_GPIOalgMode) {
+          case 0:
+            pMsg = "                   Analogue input is ignored.                    ";
+            break;
+          case 1:
+            pMsg = "                   Input 1 enables reading of analogue input to set temperature.                    ";
+          break;
+        }
+        if(pMsg)
+          _scrollMessage(56, pMsg, _startChar);
+        break;
+      case 2:
+        _display.drawFastHLine(0, 52, 128, WHITE);
+        switch(_GPIOoutMode) {
+          case 0:
+            pMsg = "                   Digital outputs are disabled.                    ";
+            break;
+          case 1:
+            pMsg = "                   Output1: LED status indicator.                    ";
+            break;
+          case 2:
+            pMsg = "                   Output 1&2: User controlled.                    ";
+            break;
+        }
+        if(pMsg)
+          _scrollMessage(56, pMsg, _startChar);
+        break;
+      case 3:
+        _display.drawFastHLine(0, 52, 128, WHITE);
+        switch(_GPIOinMode) {
+          case 0:
+            pMsg = "                   Digital inputs are disabled.                    ";
+            break;
+          case 1:
+            pMsg = "                   Input 1: Starts when closed. Input 2: Stops when closed.                    ";
+            break;
+          case 2:
+            pMsg = "                   Input 1: Starts when held closed, stops when opened. Input2: Max fuel when closed, min fuel when open.                    ";
+            break;
+          case 3:
+            pMsg = "                   Input 1: Starts or Stops when closed.                    ";
+            break;
+        }
+        if(pMsg)
+          _scrollMessage(56, pMsg, _startChar);
+        break;
+    }
+    return true;
+  }
+  return false;
+}
+
+bool 
+CGPIOScreen::keyHandler(uint8_t event)
+{
+  if(event & keyPressed) {
+    // press LEFT to select previous screen
+    if(event & key_Left) {
+      switch(_rowSel) {
+        case 0:
+          _ScreenManager.prevMenu();
+          break;
+        case 1:
+        case 2:
+        case 3:
+          _startChar = 0;
+          _adjust(-1);
+          break;
+        case 4:
+          _rowSel = 0;   // abort save
+          break;
+      }
+    }
+    // press RIGHT to select next screen
+    if(event & key_Right) {
+      switch(_rowSel) {
+        case 0:
+          _ScreenManager.nextMenu();
+          break;
+        case 1:
+        case 2:
+        case 3:
+          _startChar = 0;
+          _adjust(+1);
+          break;
+        case 4:
+          _rowSel = 0;   // abort save
+          break;
+      }
+    }
+    if(event & key_Down) {
+      _startChar = 0;
+      _rowSel--;
+      LOWERLIMIT(_rowSel, 0);
+    }
+    // UP press
+    if(event & key_Up) {
+      switch(_rowSel) {
+        case 0:
+        case 1:
+        case 2:
+        case 3:
+          _startChar = 0;
+          _rowSel++;
+          UPPERLIMIT(_rowSel, 3);
+          break;
+        case 4:    // confirmed save
+          _showStoringMessage();
+          NVstore.setGPIOinMode(_GPIOinMode);
+          NVstore.setGPIOoutMode(_GPIOoutMode);
+          NVstore.setGPIOalgMode(_GPIOalgMode);
+          saveNV();
+
+          setupGPIO();
+          
+          _rowSel = 0;
+          break;
+      }
+    }
+    // CENTRE press
+    if(event & key_Centre) {
+      switch(_rowSel) {
+        case 0:
+          _ScreenManager.selectMenu(CScreenManager::RootMenuLoop);  // force return to main menu
+          break;
+        case 1:
+        case 2:
+        case 3:
+          _rowSel = 4;
+          break;
+      }
+    }
+    _ScreenManager.reqUpdate();
+  }
+
+  return true;
+}
+
+void 
+CGPIOScreen::_adjust(int dir)
+{
+  switch(_rowSel) {
+    case 1:   // analogue mode
+      _GPIOalgMode += dir;
+      UPPERLIMIT(_GPIOalgMode, 1);
+      LOWERLIMIT(_GPIOalgMode, 0);
+      break;
+    case 2:   // outputs mode
+      _GPIOoutMode += dir;
+      ROLLLOWERLIMIT(_GPIOoutMode, 0, 2);
+      ROLLUPPERLIMIT(_GPIOoutMode, 2, 0);
+      break;
+    case 3:
+      _GPIOinMode += dir;
+      ROLLUPPERLIMIT(_GPIOinMode, 3, 0);
+      ROLLLOWERLIMIT(_GPIOinMode, 0, 3);
+      break;
+  }
+}
diff --git a/Arduino/BTCDieselHeater/src/OLED/GPIOScreen.h b/Arduino/BTCDieselHeater/src/OLED/GPIOScreen.h
new file mode 100644
index 0000000..6125b59
--- /dev/null
+++ b/Arduino/BTCDieselHeater/src/OLED/GPIOScreen.h
@@ -0,0 +1,49 @@
+/*
+ * This file is part of the "bluetoothheater" distribution 
+ * (https://gitlab.com/mrjones.id.au/bluetoothheater) 
+ *
+ * Copyright (C) 2018  Ray Jones <ray@mrjones.id.au>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef __GPIOSCREEN_H__
+#define __GPIOSCREEN_H__
+
+#include <stdint.h>
+#include "PasswordScreen.h"
+
+class C128x64_OLED;
+class CScreenManager;
+
+class CGPIOScreen : public CPasswordScreen
+{
+  int _rowSel;
+  void _adjust(int dir);
+  int _GPIOinMode;
+  int _GPIOoutMode;
+  int _GPIOalgMode;
+  int _animateCount;
+  int _startChar;
+  void _initUI();
+public:
+  CGPIOScreen(C128x64_OLED& display, CScreenManager& mgr);
+  bool show();
+  bool animate();
+  bool keyHandler(uint8_t event);
+  void onSelect();
+};
+
+#endif
diff --git a/Arduino/BTCDieselHeater/src/OLED/ThermostatModeScreen.cpp b/Arduino/BTCDieselHeater/src/OLED/ThermostatModeScreen.cpp
new file mode 100644
index 0000000..b9cc44d
--- /dev/null
+++ b/Arduino/BTCDieselHeater/src/OLED/ThermostatModeScreen.cpp
@@ -0,0 +1,262 @@
+/*
+ * This file is part of the "bluetoothheater" distribution 
+ * (https://gitlab.com/mrjones.id.au/bluetoothheater) 
+ *
+ * Copyright (C) 2018  Ray Jones <ray@mrjones.id.au>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ * 
+ */
+
+#include "128x64OLED.h"
+#include "ThermostatModeScreen.h"
+#include "KeyPad.h"
+#include "../Protocol/helpers.h"
+#include "../Utility/UtilClasses.h"
+#include "../Utility/NVStorage.h"
+
+
+///////////////////////////////////////////////////////////////////////////
+//
+// CThermostatModeScreen
+//
+// This screen provides control over experimental features
+//
+///////////////////////////////////////////////////////////////////////////
+
+static const int Line3 = 14;
+static const int Line2 = 27;
+static const int Line1 = 40;
+static const int Column = 70;
+
+CThermostatModeScreen::CThermostatModeScreen(C128x64_OLED& display, CScreenManager& mgr) : CPasswordScreen(display, mgr) 
+{
+  _initUI();
+  _window = 10;
+  _thermoMode = 0;
+  _cyclicMode = 0;
+}
+
+void 
+CThermostatModeScreen::onSelect()
+{
+  CPasswordScreen::onSelect();
+  _initUI();
+  _window = NVstore.getThermostatMethodWindow();
+  _thermoMode = NVstore.getThermostatMethodMode();
+  _cyclicMode = NVstore.getCyclicMode();
+}
+
+void
+CThermostatModeScreen::_initUI()
+{
+  _rowSel = 0;
+  _animateCount = 0;
+}
+
+bool 
+CThermostatModeScreen::show()
+{
+  char msg[20];
+  _display.clearDisplay();
+
+  if(!CPasswordScreen::show()) {  // for showing "saving settings"
+
+    if(_rowSel == 4) {
+      _printInverted(_display.xCentre(), 0, " Saving Settings ", true, eCentreJustify);
+      _printMenuText(_display.xCentre(), 35, "Press UP to", false, eCentreJustify);
+      _printMenuText(_display.xCentre(), 43, "confirm save", false, eCentreJustify);
+    }
+    else {
+      _printInverted(_display.xCentre(), 0, " Thermostat Mode ", true, eCentreJustify);
+      _printMenuText(65, Line3, "Suspend:", false, eRightJustify);
+      _printMenuText(65, Line2, "Thermostat:", false, eRightJustify);
+      _printMenuText(65, Line1, "Window:", false, eRightJustify);
+      sprintf(msg, "%.1f\367C", _window);  // \367 is octal for Adafruit degree symbol
+      _printMenuText(Column, Line1, msg, _rowSel == 1);
+      switch(_thermoMode) {
+        case 1: 
+          _printMenuText(Column, Line2, "Deadband", _rowSel == 2);
+          break;
+        case 2: 
+          _printMenuText(Column, Line2, "Linear Hz", _rowSel == 2);
+          break;
+        default: 
+          _printMenuText(Column, Line2, "Standard", _rowSel == 2);
+          break;
+      }
+      if(_cyclicMode) {
+        sprintf(msg, "> %d\367C", _cyclicMode+1);  // \367 is octal for Adafruit degree symbol
+      }
+      else {
+        strcpy(msg, "OFF");
+      }
+      _printMenuText(Column, Line3, msg, _rowSel == 3);
+    }
+  }
+
+  return true;
+}
+
+bool 
+CThermostatModeScreen::animate()
+{
+  if(_rowSel != 4) {
+    int yPos = 53;
+    int xPos = _display.xCentre();
+    const char* pMsg = NULL;
+    switch(_rowSel) {
+      case 0:
+        _printMenuText(xPos, yPos, " \021  \030Edit  Exit   \020 ", true, eCentreJustify);
+        break;
+      case 1:
+        _display.drawFastHLine(0, 52, 128, WHITE);
+        pMsg = "                    User defined window for custom thermostat modes.                    ";
+        _scrollMessage(56, pMsg, _startChar);
+        break;
+      case 2:
+        _display.drawFastHLine(0, 52, 128, WHITE);
+        switch(_thermoMode) {
+          case 1:
+            pMsg = "                   Controller holds measured temperature at the set point whilst within the window.                    ";
+            break;
+          case 2:
+            pMsg = "                   Controller uses Fixed Hz mode, adjusting pump rate linearly across the set point window.                    ";
+            break;
+          default:
+            pMsg = "                   Use heater's standard thermostat control.                    ";
+            break;
+        }
+        if(pMsg)
+          _scrollMessage(56, pMsg, _startChar);
+        break;
+      case 3:
+        _display.drawFastHLine(0, 52, 128, WHITE);
+        pMsg = "                    Controller auto cycles heater if over temperature occurs.                    ";
+        _scrollMessage(56, pMsg, _startChar);
+        break;
+    }
+    return true;
+  }
+  return false;
+}
+
+bool 
+CThermostatModeScreen::keyHandler(uint8_t event)
+{
+  if(event & keyPressed) {
+    // press LEFT to select previous screen
+    if(event & key_Left) {
+      switch(_rowSel) {
+        case 0:
+          _ScreenManager.prevMenu();
+          break;
+        case 2:
+          _startChar = 0;
+        case 1:
+        case 3:
+          _adjust(-1);
+          break;
+        case 4:
+          _rowSel = 0;   // abort save
+          break;
+      }
+    }
+    // press RIGHT to select next screen
+    if(event & key_Right) {
+      switch(_rowSel) {
+        case 0:
+          _ScreenManager.nextMenu();
+          break;
+        case 2:
+          _startChar = 0;
+        case 1:
+        case 3:
+          _adjust(+1);
+          break;
+        case 4:
+          _rowSel = 0;   // abort save
+          break;
+      }
+    }
+    if(event & key_Down) {
+      if(_rowSel == 0) {
+        _ScreenManager.selectMenu(CScreenManager::BranchMenu, CScreenManager::FontDumpUI);
+      }
+      else {
+        _rowSel--;
+        LOWERLIMIT(_rowSel, 0);
+      }
+    }
+    // UP press
+    if(event & key_Up) {
+      switch(_rowSel) {
+        case 0:
+        case 1:
+        case 2:
+        case 3:
+          _startChar = 0;
+          _rowSel++;
+          UPPERLIMIT(_rowSel, 3);
+          break;
+        case 4:    // confirmed save
+          _showStoringMessage();
+          NVstore.setThermostatMethodMode(_thermoMode);
+          NVstore.setThermostatMethodWindow(_window);
+          NVstore.setCyclicMode(_cyclicMode);
+          saveNV();
+          _rowSel = 0;
+          break;
+      }
+    }
+    // CENTRE press
+    if(event & key_Centre) {
+      switch(_rowSel) {
+        case 0:
+          _ScreenManager.selectMenu(CScreenManager::RootMenuLoop);  // force return to main menu
+          break;
+        case 1:
+        case 2:
+        case 3:
+          _rowSel = 4;
+          break;
+      }
+    }
+    _ScreenManager.reqUpdate();
+  }
+
+  return true;
+}
+
+void 
+CThermostatModeScreen::_adjust(int dir)
+{
+  switch(_rowSel) {
+    case 1:   // window
+      _window += (dir * 0.1);
+      UPPERLIMIT(_window, 6.3);
+      LOWERLIMIT(_window, 0.2);
+      break;
+    case 2:   // thermostat mode
+      _thermoMode += dir;
+      ROLLLOWERLIMIT(_thermoMode, 0, 2);
+      ROLLUPPERLIMIT(_thermoMode, 2, 0);
+      break;
+    case 3:
+      _cyclicMode += dir;
+      UPPERLIMIT(_cyclicMode, 10);
+      LOWERLIMIT(_cyclicMode, 0);
+      break;
+  }
+}
diff --git a/Arduino/BTCDieselHeater/src/OLED/ThermostatModeScreen.h b/Arduino/BTCDieselHeater/src/OLED/ThermostatModeScreen.h
new file mode 100644
index 0000000..90a1e83
--- /dev/null
+++ b/Arduino/BTCDieselHeater/src/OLED/ThermostatModeScreen.h
@@ -0,0 +1,49 @@
+/*
+ * This file is part of the "bluetoothheater" distribution 
+ * (https://gitlab.com/mrjones.id.au/bluetoothheater) 
+ *
+ * Copyright (C) 2018  Ray Jones <ray@mrjones.id.au>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ * 
+ */
+
+#ifndef __THERMOSTATMODESCREEN_H__
+#define __THERMOSTATMODESCREEN_H__
+
+#include <stdint.h>
+#include "PasswordScreen.h"
+
+class C128x64_OLED;
+class CScreenManager;
+
+class CThermostatModeScreen : public CPasswordScreen
+{
+  int _rowSel;
+  void _adjust(int dir);
+  float _window;
+  int _thermoMode;
+  int _cyclicMode;
+  int _animateCount;
+  int _startChar;
+  void _initUI();
+public:
+  CThermostatModeScreen(C128x64_OLED& display, CScreenManager& mgr);
+  bool show();
+  bool animate();
+  bool keyHandler(uint8_t event);
+  void onSelect();
+};
+
+#endif