diff --git a/EX-IOExpanderPins.h b/EX-IOExpanderPins.h
new file mode 100644
index 0000000..fa32873
--- /dev/null
+++ b/EX-IOExpanderPins.h
@@ -0,0 +1,46 @@
+/*
+ *  © 2022 Peter Cole
+ *
+ *  This file is part of EX-CommandStation
+ *
+ *  This 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.
+ *
+ *  It 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 CommandStation.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/*
+*   This file defines default pin maps for the various architectures supported
+*   by default by EX-IOExpander.
+*   
+*   Custom user defined pinmaps should be defined in myEX-IOExpander.h.
+*
+*   Any modifications to this file will be overwritten by future software updates.
+*/
+
+// #define DEFAULT_NANO_DIGITAL_PINMAP 2,3,4,5,6,7,8,9,10,11,12,13
+// #define DEFAULT_NANO_ANALOGUE_PINMAP A0,A1,A2,A3,A6,A7
+
+#define EXIO_UNO_DIGITAL_PINS 12
+#define EXIO_UNO_ANALOGUE_PINS 4
+
+#define EXIO_NANO_DIGITAL_PINS 12
+#define EXIO_NANO_ANALOGUE_PINS 6
+
+#define EXIO_MEGA_DIGITAL_PINS 46
+#define EXIO_MEGA_ANALOGUE_PINS 16
+
+// #define EXIO_UNO_DIGITAL_PINMAP 2,3,4,5,6,7,8,9,10,11,12,13
+// #define EXIO_UNO_ANALOGUE_PINMAP A0,A1,A2,A3
+
+// #define DEFAULT_MEGA_DIGITAL_PINMAP 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,22,23,24,25,26,27,28,29, \
+//                                     30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49
+// #define DEFAULT_MEGA_ANALOGUE_PINMAP A0,A1,A2,A3,A5,A6,A7,A8,A9,A10,A11,A12,A13,A14,A15
diff --git a/IO_EXIOExpander.h b/IO_EXIOExpander.h
index 0521ac7..efd09cd 100644
--- a/IO_EXIOExpander.h
+++ b/IO_EXIOExpander.h
@@ -37,7 +37,7 @@
 
 #include "IO_GPIOBase.h"
 #include "FSH.h"
-#include "EX-IOExpanderPinMaps.h"
+#include "EX-IOExpanderPins.h"
 
 // Include user defined pin maps in myEX-IOExpander if defined
 #if __has_include ("myEX-IOExpander.h")
@@ -50,16 +50,18 @@
  */
 class EXIOExpander : public IODevice {
 public:
-  static void create(VPIN vpin, int nPins, uint8_t i2cAddress) {
-    if (checkNoOverlap(vpin, nPins, i2cAddress)) new EXIOExpander(vpin, nPins, i2cAddress);
+  static void create(VPIN vpin, int nPins, uint8_t i2cAddress, uint8_t numDigitalPins, uint8_t numAnaloguePins) {
+    if (checkNoOverlap(vpin, nPins, i2cAddress)) new EXIOExpander(vpin, nPins, i2cAddress, numDigitalPins, numAnaloguePins);
   }
 
 private:  
   // Constructor
-  EXIOExpander(VPIN firstVpin, int nPins, uint8_t i2cAddress) {
+  EXIOExpander(VPIN firstVpin, int nPins, uint8_t i2cAddress, uint8_t numDigitalPins, uint8_t numAnaloguePins) {
     _firstVpin = firstVpin;
     _nPins = nPins;
     _i2cAddress = i2cAddress;
+    _numDigitalPins = numDigitalPins;
+    _numAnaloguePins = numAnaloguePins;
     addDevice(this);
   }
 
@@ -69,18 +71,44 @@ private:
 #ifdef DIAG_IO
       _display();
 #endif
+      _setupDevice();
     } else {
       DIAG(F("EX-IOExpander device not found, I2C:%x"), _i2cAddress);
       _deviceState = DEVSTATE_FAILED;
     }
   }
 
+  void _setupDevice() {
+    // Send digital and analogue pin counts
+    I2CManager.write(_i2cAddress, 3, REG_EXIOINIT, _numDigitalPins, _numAnaloguePins);
+    // Enable digital ports
+    _digitalPinBytes = (_numDigitalPins + 7) / 8;
+    uint8_t enableDigitalPins[_digitalPinBytes];
+    for (uint8_t pin = 0; pin < _numDigitalPins; pin++) {
+      int pinByte = ((pin + 7) / 8);
+      bitSet(enableDigitalPins[pinByte], (pin - (pinByte * 8)));
+    }
+    I2CManager.write(_i2cAddress, _digitalPinBytes + 1, REG_EXIODPIN, enableDigitalPins);
+    // Enable analogue ports
+    _analoguePinBytes = (_numAnaloguePins + 7) / 8;
+    uint8_t enableAnaloguePins[_analoguePinBytes];
+    for (uint8_t pin = 0; pin < _numAnaloguePins; pin++) {
+      int pinByte = ((pin + 7) / 8);
+      bitSet(enableAnaloguePins[pinByte], (pin - (pinByte * 8)));
+    }
+    I2CManager.write(_i2cAddress, _analoguePinBytes + 1, REG_EXIOAPIN, enableAnaloguePins);
+  }
+
   void _display() override {
     DIAG(F("EX-IOExpander I2C:x%x Configured on Vpins:%d-%d %S"), _i2cAddress, _firstVpin, _firstVpin+_nPins-1,
       _deviceState == DEVSTATE_FAILED ? F("OFFLINE") : F(""));
   }
 
   uint8_t _i2cAddress;
+  uint8_t _numDigitalPins;
+  uint8_t _numAnaloguePins;
+  int _digitalPinBytes;
+  int _analoguePinBytes;
 
   enum {
     REG_EXIOINIT = 0x00,    // Flag to initialise setup procedure