Allocation of GPIOs and EXTI interrupts PA0 WAKEUP EXTI0_IRQn PA1 WIRQ1 PA2 SW_USR EXTI2_IRQn (connected to INT_HUM too, but Humidity driver does not use it) PA3 WIRQ2 PA4 SPI1_NSS (slave) PA5 SPI1_SCK (slave) PA6 SPI1_MISO (slave) PA7 SPI1_MOSI (slave) PA8 I2C3_SCL PA9 UART1_TX PA10 UART1_RX PA11 EXT_GPIO0 EXTI15_10_IRQn PA12 EXT_GPIO1 EXTI15_10_IRQn PA13 SWDIO PA14 SWCLK PA15 INT_BARO EXTI15_10_IRQn PB0 I2S5_CK PB1 INT_ACCG EXTI1_IRQn PB2 LED1 (at reset it is used in input as BOOT1) PB3 INT_ALS EXTI3_IRQn PB4 I2C3_SDA PB5 INT_HALL EXTI9_5_IRQn PB6 I2C1_SCL (slave) PB7 I2C1_SDA (slave) PB8 I2S5_SD PB9 I2C2_SDA PB10 I2C2_SCL PB12 SPI2_NSS PB13 SPI2_SCK PB14 SPI2_MISO PB15 SPI2_MOSI PC13 LED0