diff --git a/MotorDriver.cpp b/MotorDriver.cpp
index 43f5e74..f8dbacf 100644
--- a/MotorDriver.cpp
+++ b/MotorDriver.cpp
@@ -57,7 +57,9 @@ MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, i
   getFastPin(F("SIG"),signalPin,fastSignalPin);
   pinMode(signalPin, OUTPUT);
 
+  #ifndef ARDUINO_ARCH_MBED_GIGA
   fastSignalPin.shadowinout = NULL;
+  #endif
   if (HAVE_PORTA(fastSignalPin.inout == &PORTA)) {
     DIAG(F("Found PORTA pin %d"),signalPin);
     fastSignalPin.shadowinout = fastSignalPin.inout;
@@ -95,7 +97,9 @@ MotorDriver::MotorDriver(int16_t power_pin, byte signal_pin, byte signal_pin2, i
     getFastPin(F("SIG2"),signalPin2,fastSignalPin2);
     pinMode(signalPin2, OUTPUT);
 
+    #ifndef ARDUINO_ARCH_MBED_ARDUINO
     fastSignalPin2.shadowinout = NULL;
+    #endif
     if (HAVE_PORTA(fastSignalPin2.inout == &PORTA)) {
       DIAG(F("Found PORTA pin %d"),signalPin2);
       fastSignalPin2.shadowinout = fastSignalPin2.inout;
diff --git a/MotorDriver.h b/MotorDriver.h
index 80caf1b..b69a493 100644
--- a/MotorDriver.h
+++ b/MotorDriver.h
@@ -30,10 +30,9 @@
 // use powers of two so we can do logical and/or on the track modes in if clauses.
 enum TRACK_MODE : byte {TRACK_MODE_NONE = 1, TRACK_MODE_MAIN = 2, TRACK_MODE_PROG = 4,
                         TRACK_MODE_DC = 8, TRACK_MODE_DCX = 16, TRACK_MODE_EXT = 32};
-#if defined(ARDUINO_GIGA)
-
-#define setHIGH(fastpin)  gpio_write(&fastpin, 1)
-#define setLOW(fastpin) gpio_write(&fastpin, 0)
+#ifdef ARDUINO_ARCH_MBED_GIGA
+#define setHIGH(fastpin) (gpio_read(&fastpin)==1)
+#define setLOW(fastpin) (gpio_read(&fastpin)==0)
 #else
 #define setHIGH(fastpin)  *fastpin.inout |= fastpin.maskHIGH
 #define setLOW(fastpin)   *fastpin.inout &= fastpin.maskLOW