diff --git a/arduino.h b/arduino.h
index 4df6f5d..62fd6f6 100644
--- a/arduino.h
+++ b/arduino.h
@@ -73,10 +73,14 @@
     #include "arduino_lpc1114.h"
   #endif
 
+  #if defined (__ARM_STM32F411__)
+    #include "arduino_stm32f411.h"
+  #endif
+
 #endif /* __AVR__, __ARMEL__, SIMULATOR */
 
 #ifndef SIMULATOR
-  #if ! defined DIO0_PIN && ! defined PIO0_1_PIN
+  #if ! defined DIO0_PIN && ! defined PIO0_1_PIN && ! defined PA_1_PIN
     #error Pins for this chip not defined in arduino.h! If you write an \
            appropriate pin definition and have this firmware work on your chip, \
            please tell us via Github or the forum thread.
diff --git a/arduino_stm32f411.h b/arduino_stm32f411.h
new file mode 100644
index 0000000..5105ad3
--- /dev/null
+++ b/arduino_stm32f411.h
@@ -0,0 +1,176 @@
+
+/** \file
+  \brief MCU pin mappings.
+
+  Here we map the pins required by Teacup to the names known by CMSIS.
+*/
+
+/** I/O pins.
+
+  In MBED, I/O pin handling is rather complicated. Lots of enums, lots of
+  functions, spread over various files, slow execution (pin toggling about
+  15 times slower than what we have here).
+
+  FASTIO by setting the BSRR (bit set/reset register), 
+  - Bit0-15 to set
+  - Bit16-31 to reset.
+
+  Pins set for Nucleo F411RE, for other STM32F4-boards you need to add them.
+*/
+
+#include "mbed-stm32f4xx.h"
+
+/**
+  We define only pins available on the Nucleo F411RE here.
+  Use alphas for PORT and numerics for PIN, close to the design.
+*/
+
+#define PA_0_PIN      0
+#define PA_0_PORT     GPIOA
+
+#define PA_1_PIN      1
+#define PA_1_PORT     GPIOA
+
+#define PA_2_PIN      2
+#define PA_2_PORT     GPIOA
+
+#define PA_3_PIN      3
+#define PA_3_PORT     GPIOA
+
+#define PA_4_PIN      4
+#define PA_4_PORT     GPIOA
+
+#define PA_5_PIN      5
+#define PA_5_PORT     GPIOA
+
+#define PA_6_PIN      6
+#define PA_6_PORT     GPIOA
+
+#define PA_7_PIN      7
+#define PA_7_PORT     GPIOA
+
+#define PA_8_PIN      8
+#define PA_8_PORT     GPIOA
+
+#define PA_9_PIN      9
+#define PA_9_PORT     GPIOA
+
+#define PA_10_PIN     10
+#define PA_10_PORT    GPIOA
+
+#define PA_11_PIN     11
+#define PA_11_PORT    GPIOA
+
+#define PA_12_PIN     12
+#define PA_12_PORT    GPIOA
+
+#define PA_13_PIN     13
+#define PA_13_PORT    GPIOA
+
+#define PA_14_PIN     14
+#define PA_14_PORT    GPIOA
+
+#define PA_15_PIN     15
+#define PA_15_PORT    GPIOA
+
+#define PB_0_PIN      0
+#define PB_0_PORT     GPIOB
+
+#define PB_1_PIN      1
+#define PB_1_PORT     GPIOB
+
+#define PB_2_PIN      2
+#define PB_2_PORT     GPIOB
+
+#define PB_3_PIN      3
+#define PB_3_PORT     GPIOB
+
+#define PB_4_PIN      4
+#define PB_4_PORT     GPIOB
+
+#define PB_5_PIN      5
+#define PB_5_PORT     GPIOB
+
+#define PB_6_PIN      6
+#define PB_6_PORT     GPIOB
+
+#define PB_7_PIN      7
+#define PB_7_PORT     GPIOB
+
+#define PB_8_PIN      8
+#define PB_8_PORT     GPIOB
+
+#define PB_9_PIN      9
+#define PB_9_PORT     GPIOB
+
+#define PB_10_PIN     10
+#define PB_10_PORT    GPIOB
+
+#define PB_12_PIN     12
+#define PB_12_PORT    GPIOB
+
+#define PB_13_PIN     13
+#define PB_13_PORT    GPIOB
+
+#define PB_14_PIN     14
+#define PB_14_PORT    GPIOB
+
+#define PB_15_PIN     15
+#define PB_15_PORT    GPIOB
+
+#define PC_0_PIN      0
+#define PC_0_PORT     GPIOC
+
+#define PC_1_PIN      1
+#define PC_1_PORT     GPIOC
+
+#define PC_2_PIN      2
+#define PC_2_PORT     GPIOC
+
+#define PC_3_PIN      3
+#define PC_3_PORT     GPIOC
+
+#define PC_4_PIN      4
+#define PC_4_PORT     GPIOC
+
+#define PC_5_PIN      5
+#define PC_5_PORT     GPIOC
+
+#define PC_6_PIN      6
+#define PC_6_PORT     GPIOC
+
+#define PC_7_PIN      7
+#define PC_7_PORT     GPIOC
+
+#define PC_8_PIN      8
+#define PC_8_PORT     GPIOC
+
+#define PC_9_PIN      9
+#define PC_9_PORT     GPIOC
+
+#define PC_10_PIN     10
+#define PC_10_PORT    GPIOC
+
+#define PC_11_PIN     11
+#define PC_11_PORT    GPIOC
+
+#define PC_12_PIN     12
+#define PC_12_PORT    GPIOC
+
+#define PC_13_PIN     13
+#define PC_13_PORT    GPIOC
+
+#define PC_14_PIN     14
+#define PC_14_PORT    GPIOC
+
+#define PC_15_PIN     15
+#define PC_15_PORT    GPIOC
+
+#define PD_2_PIN      2
+#define PD_2_PORT     GPIOD
+
+#define PH_0_PIN      0
+#define PH_0_PORT     GPIOH
+
+#define PH_1_PIN      1
+#define PH_1_PORT     GPIOH
diff --git a/pinio.h b/pinio.h
index 764abf8..21b373a 100644
--- a/pinio.h
+++ b/pinio.h
@@ -63,7 +63,7 @@
   /// Disable pullup resistor.
   #define _PULL_OFF(IO)    _WRITE(IO, 0)
 
-#elif defined __ARMEL__
+#elif defined __ARM_LPC1114__
 
   /**
     The LPC1114 supports bit-banding by mapping the bit mask to the address.
@@ -114,6 +114,32 @@
       LPC_IOCON->IO ## _CMSIS = (IO ## _OUTPUT | IO_MODEMASK_INACTIVE); \
     } while (0)
 
+#elif defined __ARM_STM32F411__
+  /**
+  */
+  /// Write to a pin.
+  #define _WRITE(IO, v) \
+    do { \
+      if (v) \
+      	IO ## _PORT->BSRR = MASK(IO ## _PIN); \
+      else \
+      	IO ## _PORT->BSRR = MASK((IO ## _PIN + 16)); \
+    } while (0)
+
+  /** Set pin as output.
+      - reset Pullup
+      - reset direction mode
+      - set output
+      - set speed
+  */
+  #define _SET_OUTPUT(IO) \
+    do { \
+      IO ## _PORT->PUPDR &= ~(3 << ((IO ## _PIN) << 1)); \
+      IO ## _PORT->MODER &= ~(3 << ((IO ## _PIN) << 1)); \
+      IO ## _PORT->MODER |= (1 << ((IO ## _PIN) << 1)); \
+      IO ## _PORT->OSPEEDR |= (3 << ((IO ## _PIN) << 1)); \
+    } while (0)
+
 #elif defined SIMULATOR
 
   #include "simulator.h"
@@ -125,7 +151,7 @@
   #define _PULLUP_ON(IO)   _WRITE(IO, 1)
   #define _PULL_OFF(IO)    _WRITE(IO, 0)
 
-#endif /* __AVR__, __ARMEL__, SIMULATOR */
+#endif /* __AVR__, __ARM_LPC1114__, __ARM_STM32F411__, SIMULATOR */
 
 /**
   Why double up on these macros?