STM32 Black Pill (F103C8)
The older STM32 Black Pill: the Blue Pill's 72 MHz STM32F103C8T6 on a black 25 x 57 mm board with its LED on PB12.
- MicrocontrollerSTM32F103C8T6, Arm Cortex-M3, up to 72 MHz
- Memory64 KB flash, 20 KB SRAM
- Chip supply voltage2.0 V to 3.6 V
- ADC2 x 12-bit, 10 channels on the 48-pin package
The STM32F103C8T6 Black Pill is a 25 x 57 mm board with ST's STM32F103C8T6, a 72 MHz Arm Cortex-M3 with 64 KB of flash and 20 KB of SRAM (ST STM32F103x8 datasheet, pp. 1, 10; stm32-base.org). Power it over micro-USB or 3.3 V on a V3.3 pin; its two 17-pin headers carry no 5 V pin, and its user LED is on PB12, lit LOW (stm32-base.org). Wire parts at 3.3 V, keeping 5 V signals off the non-5 V-tolerant pins PA0 to PA7, PB0, PB1, PB5 and PC13 (datasheet pin table, pp. 28 to 32).
The STM32F103C8T6 Black Pill is a black-PCB cousin of the Blue Pill with the same microcontroller. stm32-base.org documents it as a 25 x 57 mm board with a micro-USB socket on PA11/PA12, an ME6211 3.3 V regulator, a RESET button, BOOT0 and BOOT1 jumpers, a power LED, a user LED on PB12 and a 4-pin SWD header, with its I/O on two 17-pin headers. It is not the same board as WeAct's newer STM32F401/F411 "Black Pill", which has a USB-C port and a different chip.
The STM32F103C8 is a Cortex-M3 at up to 72 MHz with 64 KB of flash and 20 KB of SRAM in a 48-pin LQFP package, two 12-bit 1 µs ADCs with 10 channels in that package, three USARTs, two SPI, two I2C, a CAN 2.0B controller and a full-speed USB 2.0 device (ST datasheet, pp. 1, 10). It runs from 2.0 V to 3.6 V. Code written for the Blue Pill runs unchanged apart from the LED pin.
The differences from the Blue Pill are in the board, not the chip: the user LED moves from PC13 to PB12, the headers have 17 pins each and no 5V pin, and VBAT, PB2 (BOOT1), PC14 and PC15 are not brought out (stm32-base.org). As on the Blue Pill, the chip's ROM bootloader reprograms flash over USART1 only (datasheet p. 15), so an ST-LINK on the SWD header is the usual way to program it.
STM32 Black Pill (F103C8) pinout
| Pin | Function | Type |
|---|---|---|
| GND | GND (G) | power in |
| PB8 | Digital, CAN CAN RX, I2C1 SCL, PWM3.3 V, 5 V tolerant | bidirectional |
| PB9 | Digital, CAN CAN TX, I2C1 SDA, PWM3.3 V, 5 V tolerant | bidirectional |
| PC13 | Digital3.3 V | bidirectional |
| NRST | Digital3.3 V | input |
| PA0 | Digital, ADC12_IN0, PWM, UART USART2 CTS3.3 V | bidirectional |
| PA1 | Digital, ADC12_IN1, PWM, UART USART2 RTS3.3 V | bidirectional |
| PA2 | Digital, ADC12_IN2, PWM, UART USART2 TX3.3 V | bidirectional |
| PA3 | Digital, ADC12_IN3, PWM, UART USART2 RX3.3 V | bidirectional |
| PA4 | Digital, ADC12_IN4, SPI1 NSS3.3 V | bidirectional |
| PA5 | Digital, ADC12_IN5, SPI1 SCK3.3 V | bidirectional |
| PA6 | Digital, ADC12_IN6, SPI1 MISO, PWM3.3 V | bidirectional |
| PA7 | Digital, ADC12_IN7, SPI1 MOSI, PWM3.3 V | bidirectional |
| PB0 | Digital, ADC12_IN8, PWM3.3 V | bidirectional |
| PB1 | Digital, ADC12_IN9, PWM3.3 V | bidirectional |
| PB10 | Digital, I2C2 SCL, PWM, UART USART3 TX3.3 V, 5 V tolerant | bidirectional |
| PB11 | Digital, I2C2 SDA, PWM, UART USART3 RX3.3 V, 5 V tolerant | bidirectional |
| GND_2 | GND_2 (G) | power in |
| 3V3 | 3V3 (3.3)3.3 V | power out |
| PB7 | Digital, I2C1 SDA, PWM, UART USART1 RX3.3 V, 5 V tolerant | bidirectional |
| PB6 | Digital, I2C1 SCL, PWM, UART USART1 TX3.3 V, 5 V tolerant | bidirectional |
| PB5 | Digital, SPI1 MOSI, PWM3.3 V | bidirectional |
| PB4 | Digital, SPI1 MISO, PWM3.3 V, 5 V tolerant | bidirectional |
| PB3 | Digital, SPI1 SCK, PWM3.3 V, 5 V tolerant | bidirectional |
| PA15 | Digital, SPI1 NSS, PWM3.3 V, 5 V tolerant | bidirectional |
| PA12 | Digital, CAN CAN TX, UART USART1 RTS, USB USB D+3.3 V, 5 V tolerant | bidirectional |
| PA11 | Digital, CAN CAN RX, PWM, UART USART1 CTS, USB USB D-3.3 V, 5 V tolerant | bidirectional |
| PA10 | Digital, PWM, UART USART1 RX3.3 V, 5 V tolerant | bidirectional |
| PA9 | Digital, PWM, UART USART1 TX3.3 V, 5 V tolerant | bidirectional |
| PA8 | Digital, PWM3.3 V, 5 V tolerant | bidirectional |
| PB15 | Digital, SPI2 MOSI, PWM3.3 V, 5 V tolerant | bidirectional |
| PB14 | Digital, SPI2 MISO, PWM, UART USART3 RTS3.3 V, 5 V tolerant | bidirectional |
| PB13 | Digital, SPI2 SCK, PWM, UART USART3 CTS3.3 V, 5 V tolerant | bidirectional |
| PB12 | Digital, SPI2 NSS3.3 V, 5 V tolerant | bidirectional |
Specifications
- Microcontroller
- STM32F103C8T6, Arm Cortex-M3, up to 72 MHzST STM32F103x8 datasheet (Doc ID 13587 Rev 14), p. 1
- Memory
- 64 KB flash, 20 KB SRAMST STM32F103x8 datasheet, Table 2, p. 10
- Chip supply voltage
- 2.0 V to 3.6 VST STM32F103x8 datasheet, p. 1
- ADC
- 2 x 12-bit, 10 channels on the 48-pin packageST STM32F103x8 datasheet, Table 2, p. 10
- I/O current
- ±8 mA normal; 25 mA absolute max per pin, 150 mA totalST STM32F103x8 datasheet, pp. 38, 65
- Board regulator
- ME6211, 3.3 V at 180 mAstm32-base.org, STM32F103C8T6 Black Pill
- User LED
- PB12, wired as a sink (lit LOW)stm32-base.org, STM32F103C8T6 Black Pill
- Headers
- Two 17-pin headers plus a 4-pin SWD header; no 5V pinstm32-base.org, STM32F103C8T6 Black Pill
- Board size
- 25 x 57 mmstm32-base.org, STM32F103C8T6 Black Pill
- Logic level
- 3–3.3 V
- Clock speed
- 72 MHz
- Flash
- 64 KB
- RAM
- 20 KB
- GPIO pins
- 30
- ADC channels
- 10
- ADC resolution
- 12 bits
- PWM channels
- 15
- Dimensions
- 57 × 24.2 × 19.6 mm
- Weight
- 5 g
From the generic (STMicroelectronics STM32F103C8T6)'s datasheet, published by generic (STMicroelectronics STM32F103C8T6).
Common mistakes
Blinking PC13 like on a Blue Pill
This board's user LED is on PB12, not PC13 (stm32-base.org). Select the Black Pill F103 board in your core, or write to PB12 directly, LOW to light it.
Confusing it with WeAct's F411 Black Pill
WeAct's Black Pill uses an STM32F401 or F411, USB-C and an LED on PC13. Firmware, pinouts and board settings for the two are not interchangeable; check the chip marking.
Looking for a 5V pin
The headers have no 5V pin (stm32-base.org). A 5 V module needs its supply from elsewhere, with a shared ground.
Expecting USB upload out of the box
The ROM bootloader works over USART1 only (ST datasheet p. 15). Use an ST-LINK on the SWD header, or a USB-serial adapter on PA9/PA10 with BOOT0 set to 1.
5 V into an ADC pin
PA0 to PA7, PB0 and PB1 are the ADC pins and none is 5 V tolerant (datasheet pp. 28, 29). Divide a 5 V signal down to 3.3 V first.
STM32 Black Pill (F103C8) questions
Is the STM32F103 Black Pill 5 V tolerant?
Partly. FT pins tolerate 5 V as digital inputs; PA0 to PA7, PB0, PB1, PB5 and PC13 do not, and no pin does in analog mode (ST STM32F103x8 datasheet, pp. 28 to 32).
STM32F103 Black Pill vs Blue Pill: what is the difference?
Same STM32F103C8T6 chip, different board. The Black Pill moves the LED to PB12, uses two 17-pin headers with no 5V pin and an ME6211 regulator rated 180 mA; the Blue Pill has its LED on PC13, two 20-pin headers with 5V and VBAT, and a 300 mA regulator (stm32-base.org).
STM32F103 Black Pill vs WeAct STM32F411 Black Pill?
The F411 Black Pill has a 100 MHz Cortex-M4 with FPU, 512 KB of flash, 128 KB of SRAM and USB DFU in its ROM bootloader (ST STM32F411xC/xE datasheet, pp. 1, 12, 20), against the F103's 72 MHz, 64 KB and 20 KB (ST STM32F103x8 datasheet, p. 10). For new work the F411 board is the stronger choice.
Why won't my Black Pill upload?
Check the ST-LINK's four SWD wires and try holding RST while the upload starts. For serial upload, set BOOT0 to 1, press RST and connect the adapter to PA9 (TX) and PA10 (RX), the USART1 pins the ROM bootloader uses (ST datasheet p. 15). Set BOOT0 back to 0 afterwards.
Which pin is the built-in LED on the STM32F103 Black Pill?
PB12, wired as a sink so it lights when the pin is LOW (stm32-base.org).
Build something with the STM32 Black Pill (F103C8)
- Build this
Panel-mounted controller
Use the F103's timers and ADC for a small machine controller on a stripboard.
- Build this
USB HID device
Build a custom keyboard or joystick with the chip's full-speed USB device.
- Build this
CAN bus sniffer
Pair the CAN controller with a transceiver to log or inject messages.
- Build this
Multi-channel data logger
Sample up to ten analog inputs with the 12-bit ADCs and stream them over serial.
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