diff --git a/CommandStation-EX.ino b/CommandStation-EX.ino
index cd23f0e..d2627ea 100644
--- a/CommandStation-EX.ino
+++ b/CommandStation-EX.ino
@@ -66,6 +66,7 @@ void setup()
   SerialManager::init();
 
   DIAG(F("License GPLv3 fsf.org (c) dcc-ex.com"));
+  DIAG(F("Platform: %s"), F(ARDUINO_TYPE)); // PMA - temporary
 
   CONDITIONAL_LCD_START {
     // This block is still executed for DIAGS if LCD not in use
@@ -85,7 +86,7 @@ void setup()
 #endif // ETHERNET_ON
 
 // Initialise HAL layer before reading EEprom or setting up MotorDrivers 
-  IODevice::begin();
+//  IODevice::begin();
 
   // Responsibility 3: Start the DCC engine.
   // Note: this provides DCC with two motor drivers, main and prog, which handle the motor shield(s)
@@ -100,18 +101,18 @@ void setup()
 
   // Invoke any DCC++EX commands in the form "SETUP("xxxx");"" found in optional file mySetup.h.
   //  This can be used to create turnouts, outputs, sensors etc. through the normal text commands.
+// PMA - how to handle __has_include??
   #if __has_include ( "mySetup.h")
-  #define SETUP(cmd) DCCEXParser::parse(F(cmd))
-  #include "mySetup.h"
-  #undef SETUP
+    #define SETUP(cmd) DCCEXParser::parse(F(cmd))
+    #include "mySetup.h"
+    #undef SETUP
   #endif
 
-  #if defined(LCN_SERIAL)
-  LCN_SERIAL.begin(115200);
-  LCN::init(LCN_SERIAL);
-  #endif
-
-  LCD(3,F("Ready"));
+//  #if defined(LCN_SERIAL)
+//  LCN_SERIAL.begin(115200);
+//  LCN::init(LCN_SERIAL);
+//  #endif
+  LCD(3, F("Ready"));
   CommandDistributor::broadcastPower();
 }
 
@@ -121,7 +122,7 @@ void loop()
 
   // Responsibility 1: Handle DCC background processes
   //                   (loco reminders and power checks)
-  DCC::loop();
+//  DCC::loop();
 
   // Responsibility 2: handle any incoming commands on USB connection
   SerialManager::loop();
@@ -134,18 +135,18 @@ void loop()
   EthernetInterface::loop();
 #endif
 
-  RMFT::loop();  // ignored if no automation
+//  RMFT::loop();  // ignored if no automation
 
   #if defined(LCN_SERIAL)
   LCN::loop();
   #endif
 
-  LCDDisplay::loop();  // ignored if LCD not in use
+//  LCDDisplay::loop();  // ignored if LCD not in use
 
   // Handle/update IO devices.
-  IODevice::loop();
+  //IODevice::loop();
 
-  Sensor::checkAll(); // Update and print changes
+  //Sensor::checkAll(); // Update and print changes
 
   // Report any decrease in memory (will automatically trigger on first call)
   static int ramLowWatermark = __INT_MAX__; // replaced on first loop
diff --git a/DCCEXParser.cpp b/DCCEXParser.cpp
index 2fc8f6b..ad4054d 100644
--- a/DCCEXParser.cpp
+++ b/DCCEXParser.cpp
@@ -781,7 +781,9 @@ bool DCCEXParser::parseD(Print *stream, int16_t params, int16_t p[])
           wdt_enable( WDTO_15MS); // set Arduino watchdog timer for 15ms 
           delay(50);            // wait for the prescaller time to expire
 #else
+#ifdef ARDUINO_ARCH_ESP
 	  ESP.restart();
+#endif
 #endif
           break; // and <X> if we didnt restart 
         }
diff --git a/DCCTimerSAMD.cpp b/DCCTimerSAMD.cpp
new file mode 100644
index 0000000..74ec18b
--- /dev/null
+++ b/DCCTimerSAMD.cpp
@@ -0,0 +1,90 @@
+/*
+ *  © 2021 Mike S
+ *  © 2021 Harald Barth
+ *  © 2021 Fred Decker
+ *  © 2021 Chris Harlow
+ *  © 2021 David Cutting
+ *  © 2022 Paul M. Antoine
+ *  All rights reserved.
+ *  
+ *  This file is part of Asbelos DCC API
+ *
+ *  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/>.
+ */
+
+// ATTENTION: this file only compiles on a TEENSY
+// Please refer to DCCTimer.h for general comments about how this class works
+// This is to avoid repetition and duplication.
+#ifdef ARDUINO_ARCH_SAMD
+
+#include "FSH.h" //PMA temp debug
+#include "DIAG.h" //PMA temp debug
+#include "DCCTimer.h"
+
+INTERRUPT_CALLBACK interruptHandler=0;
+
+void DCCTimer::begin(INTERRUPT_CALLBACK callback) {
+  interruptHandler=callback;
+
+
+
+
+  }
+
+bool DCCTimer::isPWMPin(byte pin) {
+       //SAMD: digitalPinHasPWM, todo
+      (void) pin;
+       return false;  // TODO what are the relevant pins? 
+  }
+
+void DCCTimer::setPWM(byte pin, bool high) {
+    // TODO what are the relevant pins?
+    (void) pin;
+    (void) high;
+}
+
+void   DCCTimer::getSimulatedMacAddress(byte mac[6]) {
+  volatile uint32_t *serno1 = (volatile uint32_t *)0x0080A00C;
+  volatile uint32_t *serno2 = (volatile uint32_t *)0x0080A040;
+//  volatile uint32_t *serno3 = (volatile uint32_t *)0x0080A044;
+//  volatile uint32_t *serno4 = (volatile uint32_t *)0x0080A048;
+
+  volatile uint32_t m1 = *serno1;
+  volatile uint32_t m2 = *serno2;
+  mac[0] = m1 >> 8;
+  mac[1] = m1 >> 0;
+  mac[2] = m2 >> 24;
+  mac[3] = m2 >> 16;
+  mac[4] = m2 >> 8;
+  mac[5] = m2 >> 0;
+}
+
+volatile int DCCTimer::minimum_free_memory=__INT_MAX__;
+
+// Return low memory value... 
+int DCCTimer::getMinimumFreeMemory() {
+  noInterrupts(); // Disable interrupts to get volatile value 
+  int retval = freeMemory();
+  interrupts();
+  return retval;
+}
+
+extern "C" char* sbrk(int incr);
+
+int DCCTimer::freeMemory() {
+  char top;
+  return (int)(&top - reinterpret_cast<char *>(sbrk(0)));
+}
+
+#endif
\ No newline at end of file
diff --git a/I2CManager.h b/I2CManager.h
index 1163261..67fd1ad 100644
--- a/I2CManager.h
+++ b/I2CManager.h
@@ -111,10 +111,10 @@
  */
 
 // Uncomment following line to enable Wire library instead of native I2C drivers
-//#define I2C_USE_WIRE
+#define I2C_USE_WIRE
 
 // Uncomment following line to disable the use of interrupts by the native I2C drivers.
-//#define I2C_NO_INTERRUPTS
+#define I2C_NO_INTERRUPTS
 
 // Default to use interrupts within the native I2C drivers.
 #ifndef I2C_NO_INTERRUPTS
diff --git a/MotorDriver.cpp b/MotorDriver.cpp
index 517e2dd..c40a0f1 100644
--- a/MotorDriver.cpp
+++ b/MotorDriver.cpp
@@ -192,8 +192,12 @@ int MotorDriver::mA2raw( unsigned int mA) {
 
 void  MotorDriver::getFastPin(const FSH* type,int pin, bool input, FASTPIN & result) {
     // DIAG(F("MotorDriver %S Pin=%d,"),type,pin);
-    (void) type; // avoid compiler warning if diag not used above. 
+    (void) type; // avoid compiler warning if diag not used above.
+#if defined(ARDUINO_ARCH_SAMD)
+    PortGroup *port = digitalPinToPort(pin);
+#else
     uint8_t port = digitalPinToPort(pin);
+#endif
     if (input)
       result.inout = portInputRegister(port);
     else
diff --git a/MotorDriver.h b/MotorDriver.h
index 981b259..3a21b89 100644
--- a/MotorDriver.h
+++ b/MotorDriver.h
@@ -30,7 +30,7 @@
 #define UNUSED_PIN 127 // inside int8_t
 #endif
 
-#if defined(__IMXRT1062__) || defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32)
+#if defined(__IMXRT1062__) || defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32) || defined(ARDUINO_ARCH_SAMD)
 struct FASTPIN {
   volatile uint32_t *inout;
   uint32_t maskHIGH;  
diff --git a/SerialManager.cpp b/SerialManager.cpp
index 8717227..2dce51b 100644
--- a/SerialManager.cpp
+++ b/SerialManager.cpp
@@ -32,9 +32,15 @@ SerialManager::SerialManager(Stream * myserial) {
 } 
 
 void SerialManager::init() {
-  while (!Serial && millis() < 5000); // wait max 5s for Serial to start
+//  while (!Serial && millis() < 5000); // wait max 5s for Serial to start
+#if defined(ARDUINO_ARCH_SAMD)
+  SerialUSB.begin(115200);
+  while (!SerialUSB); // PMA - temporary for debuggering purpoises
+  new SerialManager(&SerialUSB);
+#else
   Serial.begin(115200);
   new SerialManager(&Serial);
+#endif
 #ifdef SERIAL3_COMMANDS
   Serial3.begin(115200);
   new SerialManager(&Serial3);
diff --git a/defines.h b/defines.h
index c24d6af..aba5daf 100644
--- a/defines.h
+++ b/defines.h
@@ -77,14 +77,15 @@
 // This defines the speed at which the Arduino will communicate with the ESP8266 module.
 // Currently only devices which can communicate at 115200 are supported.
 //
-#define WIFI_SERIAL_LINK_SPEED 115200
+#define WIFI_SERIAL_LINK_SPEED 9600
 
-#if __has_include ( "myAutomation.h")
-  #if defined(BIG_RAM) || defined(DISABLE_EEPROM)
-    #define EXRAIL_ACTIVE
-  #else
-    #define EXRAIL_WARNING
-  #endif
-#endif
+// TODO: PMA - figure out why enabling this causes the CS to crashe immediately after starting the motor driver
+//#if __has_include ( "myAutomation.h")
+//  #if defined(BIG_RAM) || defined(DISABLE_EEPROM)
+//    #define EXRAIL_ACTIVE
+//  #else
+//    #define EXRAIL_WARNING
+//  #endif
+//#endif
 
 #endif
diff --git a/platformio.ini b/platformio.ini
index 8bba297..59136b3 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -10,13 +10,9 @@
 
 [platformio]
 default_envs = 
-	mega2560
-	uno
-	mega328
-	unowifiR2
-	nano
-src_dir = .
-include_dir = .
+	samd21
+src_dir = /Users/paul/Projects/CommandStation-EX
+include_dir = /Users/paul/Projects/CommandStation-EX
 
 [env]
 build_flags = -Wall -Wextra
@@ -25,12 +21,13 @@ build_flags = -Wall -Wextra
 platform = atmelsam
 board = sparkfun_samd21_dev_usb
 framework = arduino
-upload_protocol = atmel-ice
+upload_protocol = sam-ba
 lib_deps = 
 	${env.lib_deps}
 	SparkFun External EEPROM Arduino Library
 monitor_speed = 115200
 monitor_flags = --echo
+build_flags = -std=c++17
 
 [env:mega2560-debug]
 platform = atmelavr
@@ -131,7 +128,6 @@ platform = atmelavr
 board = nanoatmega328new
 board_upload.maximum_size = 32256
 framework = arduino
-lib_deps = 
-	${env.lib_deps}
+lib_deps = ${env.lib_deps}
 monitor_speed = 115200
 monitor_flags = --echo