diff --git a/STM32F4/cores/maple/libmaple/gpio_def.h b/STM32F4/cores/maple/libmaple/gpio_def.h
index 970386c9a..1f26e8160 100644
--- a/STM32F4/cores/maple/libmaple/gpio_def.h
+++ b/STM32F4/cores/maple/libmaple/gpio_def.h
@@ -243,6 +243,7 @@ typedef enum {
     GPIO_AFMODE_USART4_6 = 8,
     GPIO_AFMODE_CAN1_2   = 9,
     GPIO_AFMODE_TIM12_14 = 9,
+    GPIO_AFMODE_I2C2_3   = 9,
     GPIO_AFMODE_OTG_FS   = 10,
     GPIO_AFMODE_ETH      = 11,
     GPIO_AFMODE_FSMC     = 12,
diff --git a/STM32F4/cores/maple/libmaple/i2c.c b/STM32F4/cores/maple/libmaple/i2c.c
index 4cf413bd9..cc173def4 100644
--- a/STM32F4/cores/maple/libmaple/i2c.c
+++ b/STM32F4/cores/maple/libmaple/i2c.c
@@ -43,8 +43,16 @@
 /** I2C1 device */
 i2c_dev i2c_dev1 = {
     .regs         = I2C1_BASE,
-    .sda_pin      = PB7, // PB8
+#ifdef BOARD_I2C1_SDA_PIN    
+    .sda_pin      = BOARD_I2C1_SDA_PIN, 
+#else
+    .sda_pin      = PB7, 
+#endif    
+#ifdef BOARD_I2C1_SCL_PIN    
+    .scl_pin      = BOARD_I2C1_SCL_PIN, 
+#else
     .scl_pin      = PB6,
+#endif
     .clk_id       = RCC_I2C1,
     .ev_nvic_line = NVIC_I2C1_EV,
     .er_nvic_line = NVIC_I2C1_ER,
@@ -55,8 +63,16 @@ i2c_dev i2c_dev1 = {
 /** I2C2 device */
 i2c_dev i2c_dev2 = {
     .regs         = I2C2_BASE,
-    .sda_pin      = PB11,
+#ifdef BOARD_I2C2_SDA_PIN    
+    .sda_pin      = BOARD_I2C2_SDA_PIN, 
+#else
+    .sda_pin      = PB11, 
+#endif    
+#ifdef BOARD_I2C2_SCL_PIN    
+    .scl_pin      = BOARD_I2C2_SCL_PIN, 
+#else
     .scl_pin      = PB10,
+#endif
     .clk_id       = RCC_I2C2,
     .ev_nvic_line = NVIC_I2C2_EV,
     .er_nvic_line = NVIC_I2C2_ER,
@@ -64,6 +80,27 @@ i2c_dev i2c_dev2 = {
 };
 #endif
 
+#if BOARD_NR_I2C>2
+/** I2C2 device */
+i2c_dev i2c_dev3 = {
+    .regs         = I2C3_BASE,
+#ifdef BOARD_I2C3_SDA_PIN    
+    .sda_pin      = BOARD_I2C3_SDA_PIN, 
+#else
+    .sda_pin      = PC9, 
+#endif    
+#ifdef BOARD_I2C3_SCL_PIN    
+    .scl_pin      = BOARD_I2C3_SCL_PIN, 
+#else
+    .scl_pin      = PA8,
+#endif
+    .clk_id       = RCC_I2C3,
+    .ev_nvic_line = NVIC_I2C3_EV,
+    .er_nvic_line = NVIC_I2C3_ER,
+    .state        = I2C_STATE_DISABLED
+};
+#endif
+
 static inline int32 wait_for_state_change(i2c_dev *dev,
                                           i2c_state state,
                                           uint32 timeout);
@@ -206,7 +243,14 @@ void i2c_master_enable(i2c_dev *dev, uint32 flags) {
     delay_us(2);
     gpio_set_af_mode(dev->scl_pin, GPIO_AFMODE_I2C1_3);
     delay_us(2);
-    gpio_set_af_mode(dev->sda_pin, GPIO_AFMODE_I2C1_3);
+    /* specific SDA pin remap for I2C2 on F4xx mcu*/
+    if ((dev->sda_pin == PB3) || (dev->sda_pin == PB4)) {
+        gpio_set_af_mode(dev->sda_pin, GPIO_AFMODE_I2C2_3);
+    }
+    else {
+        gpio_set_af_mode(dev->sda_pin, GPIO_AFMODE_I2C1_3);
+    }
+   
 
     i2c_init(dev);
 
@@ -512,6 +556,11 @@ void __irq_i2c2_ev(void) {
    i2c_irq_handler(&i2c_dev2);
 }
 #endif
+#if BOARD_NR_I2C>2
+void __irq_i2c3_ev(void) {
+   i2c_irq_handler(&i2c_dev3);
+}
+#endif
 /**
  * @brief Interrupt handler for I2C error conditions
  * @param dev I2C device
@@ -541,6 +590,11 @@ void __irq_i2c2_er(void) {
     i2c_irq_error_handler(&i2c_dev2);
 }
 #endif
+#if BOARD_NR_I2C>2
+void __irq_i2c3_er(void) {
+    i2c_irq_error_handler(&i2c_dev3);
+}
+#endif
 /*
  * CCR/TRISE configuration helper
  */
diff --git a/STM32F4/cores/maple/libmaple/i2c.h b/STM32F4/cores/maple/libmaple/i2c.h
index d962124d8..cc36a161e 100644
--- a/STM32F4/cores/maple/libmaple/i2c.h
+++ b/STM32F4/cores/maple/libmaple/i2c.h
@@ -100,6 +100,10 @@ extern i2c_dev i2c_dev1;
 extern i2c_dev i2c_dev2;
 #define I2C2 (&i2c_dev2)
 #endif
+#if BOARD_NR_I2C>2
+extern i2c_dev i2c_dev3;
+#define I2C3 (&i2c_dev3)
+#endif
 
 /*
  * Register map base pointers
@@ -109,6 +113,8 @@ extern i2c_dev i2c_dev2;
 #define I2C1_BASE               ((struct i2c_reg_map*)0x40005400)
 /** I2C2 register map base pointer */
 #define I2C2_BASE               ((struct i2c_reg_map*)0x40005800)
+/** I2C3 register map base pointer */
+#define I2C3_BASE               ((struct i2c_reg_map*)0x40005C00)
 
 /*
  * Register bit definitions
diff --git a/STM32F4/libraries/Wire/Wire.cpp b/STM32F4/libraries/Wire/Wire.cpp
index dbc61f0e3..351aa8a6f 100644
--- a/STM32F4/libraries/Wire/Wire.cpp
+++ b/STM32F4/libraries/Wire/Wire.cpp
@@ -67,6 +67,11 @@ TwoWire::TwoWire(uint8 dev_sel, uint8 flags) {
 	else if (dev_sel == 2) {
         sel_hard = I2C2;
     }
+#endif
+#if BOARD_NR_I2C>2
+	else if (dev_sel == 3) {
+        sel_hard = I2C3;
+    }
 #endif
 	else {
         ASSERT(1);
diff --git a/STM32F4/variants/blackpill_f401/blackpill_f401.h b/STM32F4/variants/blackpill_f401/blackpill_f401.h
index acd990142..87e28c9f5 100644
--- a/STM32F4/variants/blackpill_f401/blackpill_f401.h
+++ b/STM32F4/variants/blackpill_f401/blackpill_f401.h
@@ -52,11 +52,15 @@
 //#define BOARD_USART6_TX_PIN     PA11 // USB_DM
 //#define BOARD_USART6_RX_PIN     PA12 // USB_DP
 
-#define BOARD_NR_I2C            1
+#define BOARD_NR_I2C            3
 #define BOARD_I2C1_SCL_PIN      PB6
 #define BOARD_I2C1_SDA_PIN      PB7
 #define BOARD_I2C1A_SCL_PIN     PB8
 #define BOARD_I2C1A_SDA_PIN     PB9
+#define BOARD_I2C2_SCL_PIN      PB10
+#define BOARD_I2C2_SDA_PIN      PB3
+#define BOARD_I2C3_SCL_PIN      PA8
+#define BOARD_I2C3_SDA_PIN      PB4
 
 #define BOARD_NR_SPI            3
 #define BOARD_SPI1_NSS_PIN      PA4
diff --git a/STM32F4/variants/blackpill_f411/blackpill_f411.h b/STM32F4/variants/blackpill_f411/blackpill_f411.h
index 103a12251..5d7b5cb34 100644
--- a/STM32F4/variants/blackpill_f411/blackpill_f411.h
+++ b/STM32F4/variants/blackpill_f411/blackpill_f411.h
@@ -53,11 +53,15 @@
 //#define BOARD_USART6_TX_PIN     PA11 // USB_DM
 //#define BOARD_USART6_RX_PIN     PA12 // USB_DP
 
-#define BOARD_NR_I2C            1
+#define BOARD_NR_I2C            3
 #define BOARD_I2C1_SCL_PIN      PB6
 #define BOARD_I2C1_SDA_PIN      PB7
 #define BOARD_I2C1A_SCL_PIN     PB8
 #define BOARD_I2C1A_SDA_PIN     PB9
+#define BOARD_I2C2_SCL_PIN      PB10
+#define BOARD_I2C2_SDA_PIN      PB3
+#define BOARD_I2C3_SCL_PIN      PA8
+#define BOARD_I2C3_SDA_PIN      PB4
 
 #define BOARD_NR_SPI            3
 #define BOARD_SPI1_NSS_PIN      PA4