Add TWI_PINS_6_7 for Butterfly

Author: GrumpyOldPizza

libraries/Wire/src/Wire.cpp

@@ -444,7 +444,7 @@ void TwoWireEx::begin(TwoWireExPins pins)
 {
     _option = I2C_OPTION_RESET;
 
-    if (pins == TWI_PINS_42_43) {
+    if (pins != TWI_PINS_20_21) {
 	_option |= I2C_OPTION_ALTERNATE;
     }
 
@@ -455,7 +455,7 @@ void TwoWireEx::begin(uint8_t address, TwoWireExPins pins)
 {
     _option = I2C_OPTION_RESET | (address << I2C_OPTION_ADDRESS_SHIFT);
 
-    if (pins == TWI_PINS_42_43) {
+    if (pins != TWI_PINS_20_21) {
 	_option |= I2C_OPTION_ALTERNATE;
     }
 

libraries/Wire/src/Wire.h

@@ -107,7 +107,13 @@ class TwoWire : public Stream
     friend class TwoWireEx;
 };
 
+#if defined(STM32L433xx)
+enum TwoWireExPins { TWI_PINS_20_21 = 0, TWI_PINS_6_7 = 1 };
+#elif defined(STM32L476xx) || defined(STM32L496xx)
 enum TwoWireExPins { TWI_PINS_20_21 = 0, TWI_PINS_42_43 = 1 };
+#else
+enum TwoWireExPins { TWI_PINS_20_21 = 0 };
+#endif
 
 class TwoWireEx : public TwoWire
 {

system/STM32L4xx/Lib/libstm32l432.a

@@ -914,6 +914,14 @@ bool stm32l4_i2c_configure(stm32l4_i2c_t *i2c, uint32_t clock, uint32_t option)
     }
 #endif /* defined(STM32L476xx) */
 
+#if defined(STM32L433xx)
+    if ((i2c->option & I2C_OPTION_ALTERNATE) && (pin_scl == GPIO_PIN_PB6_I2C1_SCL) && (pin_sda == GPIO_PIN_PB7_I2C1_SDA))
+    {
+	pin_scl = GPIO_PIN_PB8_I2C1_SCL;
+	pin_sda = GPIO_PIN_PB9_I2C1_SDA;
+    }
+#endif /* defined(STM32L433xx) */
+
 #if defined(STM32L476xx) ||  defined(STM32L496xx)
     if ((i2c->option & I2C_OPTION_ALTERNATE) && (pin_scl == GPIO_PIN_PB8_I2C1_SCL) && (pin_sda == GPIO_PIN_PB9_I2C1_SDA))
     {
@@ -1073,6 +1081,14 @@ bool stm32l4_i2c_reset(stm32l4_i2c_t *i2c)
     pin_scl = i2c->pins.scl;
     pin_sda = i2c->pins.sda;
 
+#if defined(STM32L433xx)
+    if ((i2c->option & I2C_OPTION_ALTERNATE) && (pin_scl == GPIO_PIN_PB6_I2C1_SCL) && (pin_sda == GPIO_PIN_PB7_I2C1_SDA))
+    {
+	pin_scl = GPIO_PIN_PB8_I2C1_SCL;
+	pin_sda = GPIO_PIN_PB9_I2C1_SDA;
+    }
+#endif /* defined(STM32L433xx) */
+
 #if defined(STM32L476xx) ||  defined(STM32L496xx)
     if ((i2c->option & I2C_OPTION_ALTERNATE) && (pin_scl == GPIO_PIN_PB8_I2C1_SCL) && (pin_sda == GPIO_PIN_PB9_I2C1_SDA))
     {