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