BluePill F103CB

Below are the pins usable for the peripherals. Pins in bold are the default.

SPI

Instance MOSI MISO SCK
SPI1 PA7, PB5 PA6, PB4 PA5, PB3
SPI2 PB15 PB14 PB13

I2C

Instance SDA SCL
I2C1 PB7, PB9 PB6, PB8
I2C2 PB11 PB10

USART

Instance RX TX
USART1 PA10, PB7 PA9, PB6
USART2 PA3 PA2
USART3 PB11 PB10

TIM

Instance CH1 CH2 CH3 CH4
TIM1 PA8, PA7, PB13 PA9, PB0, PB14 PA10, PB1, PB15 PA11
TIM2 PA0, PA15 PA1, PB3 PA2, PB10 PA3, PB11
TIM3 PA6, PB4 PA7, PB5 PB0 PB1
TIM4 PB6 PB7 PB8 PB9

ADC

Instance Channel Pin
ADC1 IN0 PA0
ADC1 IN1 PA1
ADC1 IN2 PA2
ADC1 IN3 PA3
ADC1 IN4 PA4
ADC1 IN5 PA5
ADC1 IN6 PA6
ADC1 IN7 PA7
ADC1 IN8 PB0
ADC1 IN9 PB1
ADC2 IN0 PA0
ADC2 IN1 PA1
ADC2 IN2 PA2
ADC2 IN3 PA3
ADC2 IN4 PA4
ADC2 IN5 PA5
ADC2 IN6 PA6
ADC2 IN7 PA7
ADC2 IN8 PB0
ADC2 IN9 PB1

GPIO

Pin Peripheral signal available on the pin Board macro
PA0 ADC1_IN0, ADC2_IN0, SYS_WKUP, TIM2_CH1, TIM2_ETR, USART2_CTS
PA1 ADC1_IN1, ADC2_IN1, TIM2_CH2, USART2_RTS
PA2 ADC1_IN2, ADC2_IN2, TIM2_CH3, USART2_TX
PA3 ADC1_IN3, ADC2_IN3, TIM2_CH4, USART2_RX
PA4 ADC1_IN4, ADC2_IN4, SPI1_NSS, USART2_CK SS
PA5 ADC1_IN5, ADC2_IN5, SPI1_SCK SCK
PA6 ADC1_IN6, ADC2_IN6, SPI1_MISO, TIM1_BKIN, TIM3_CH1 MISO
PA7 ADC1_IN7, ADC2_IN7, SPI1_MOSI, TIM1_CH1N, TIM3_CH2 MOSI
PA8 RCC_MCO, TIM1_CH1, USART1_CK
PA9 TIM1_CH2, USART1_TX
PA10 TIM1_CH3, USART1_RX
PA11 CAN_RX, TIM1_CH4, USART1_CTS, USB_DM
PA12 CAN_TX, TIM1_ETR, USART1_RTS, USB_DP
PA13 SYS_JTMS-SWDIO
PA14 SYS_JTCK-SWCLK
PA15 SPI1_NSS, SYS_JTDI, TIM2_CH1, TIM2_ETR
PB0 ADC1_IN8, ADC2_IN8, TIM1_CH2N, TIM3_CH3
PB1 ADC1_IN9, ADC2_IN9, TIM1_CH3N, TIM3_CH4
PB2
PB3 SPI1_SCK, SYS_JTDO-TRACESWO, TIM2_CH2
PB4 SPI1_MISO, SYS_NJTRST, TIM3_CH1
PB5 I2C1_SMBA, SPI1_MOSI, TIM3_CH2
PB6 I2C1_SCL, TIM4_CH1, USART1_TX SCL
PB7 I2C1_SDA, TIM4_CH2, USART1_RX SDA
PB8 CAN_RX, I2C1_SCL, TIM4_CH3
PB9 CAN_TX, I2C1_SDA, TIM4_CH4
PB10 I2C2_SCL, TIM2_CH3, USART3_TX
PB11 ADC1_EXTI11, ADC2_EXTI11, I2C2_SDA, TIM2_CH4, USART3_RX
PB12 I2C2_SMBA, SPI2_NSS, TIM1_BKIN, USART3_CK
PB13 SPI2_SCK, TIM1_CH1N, USART3_CTS
PB14 SPI2_MISO, TIM1_CH2N, USART3_RTS
PB15 SPI2_MOSI, TIM1_CH3N
PC13 RTC_OUT, RTC_TAMPER LED_BUILTIN
PC14 RCC_OSC32_IN
PC15 ADC1_EXTI15, ADC2_EXTI15, RCC_OSC32_OUT
PD0 RCC_OSC_IN
PD1 RCC_OSC_OUT