Description:

STM32F103C8T6, the core board is replaced by STM32F103C6T6.In most cases, C6T6 can replace C8T6. If the program is relatively large or the serial port 3 used cannot be replaced, what about the program size? Please see the introduction below.

The difference between STM32F103C6T6 and C8T6:

1. C6T6 has no serial port 3.
2. The flash of C6T6 is 32K, and the flash of C8T6 is 64K.
3. The RAM of C6T6 is 10K, and the RAM of C8T6 is 20K.After Keil software is compiled, it will prompt the usage of Code, RO-data, RW-data, ZI-data; where falsh=”Code”+”RO-data”+”RW-data”, RAM=”RW-data”+ “ZI-data”.

The ARM Cortex M3 STM32F103C6 Microcontroller is used in the Blue pill board. Unlike the name, “Blue Pill” the Microcontroller’s name STM32F103C6T6 has a meaning behind it.

• STM » stands for the manufacturer name STMicroelectronics
• 32 » stands for 32-bit ARM architecture
• F103 » stands to indicate that the architecture ARM Cortex M3
• C » 48-pin
• 6 » 32KB Flash memory
• T » package type is LQFP
• 6 » operating temperature -40°C to +85°C

Now let us look into the specifications of this Microcontroller.

• Architecture: 32-bit ARM Cortex M3
• Operating Voltage: 2V to 3.6V
• CPU Frequency: 72 MHz
• Number of GPIO pins: 32
• Number of PWM pins: 12
• Analog input Pins: 10 (12-bit)
• USART Peripherals: 2
• I2C Peripherals: 1
• SPI Peripherals: 1
• Can 2.0 Peripheral: 1
• Timers: 2 (16-bit), 1 (PWM)
• Flash Memory: 32KB
• RAM: 10kB
• Burning times: 10k cycles
• On-board SWD interface and it can be programmed with ST-LINK V2
• Immersion gold process, long service life
• On-board reset button and power indicator LED
• Power supply connector: Micro USB socket
• On-board test indicator LED and the beginners can program to control it
• On-board 100ma 3.3V Regulator
• Size: 53mm x 22.5mm

STM32 Pin Details

The complete pin-outs of the STM32 Blue pill board are shown below. As you can see each pin is neatly labeled against it. The labeling is also similar to the Arduino boards. That is the G is used to denote the ground pin, 3.3V outputs a regulated 3.3V and the 5V pin can either be used to power the board or obtain the +5V if powered via micro USB. The onboard LED is connected to the PC13 pin of the Microcontroller.

Understanding Blue Pill

The Blue Pill is a 32-bit Arduino-compatible development board that features the STM32F103C6T6, a member of the STM32 family of ARM Cortex-M3 core microcontrollers. This board aims to bring the 32-bit ARM Cortex microcontrollers to the hobbyist market with the Arduino-style form factor.

Powering your Blue Pill:

There are three ways of powering your Blue Pill development board:

• Using the built-in USB micro connector.
• Supplying 5V to the 5V pin as an external supply.
• Supplying 3.3V directly to the 3.3V pin.

How to Use the STM32 Development Board?

The Blue Pill can be programmed in two ways–

• Using an external USB/Serial converter connected to UART1 pins, which is the default bootloader for this family of boards. It can be programmed using the Arduino software this way.
• STLink USB Dongle – this uses the single-wire debug interface to communicate with the board. This allows it to be programmed using advanced software like Keil/CubeMX. It also allows memory access using the STLink software.

Before programming, it is important to connect the BOOT0 jumper to 1 and press the reset button to put the chip in ‘programming mode’.

Uploading Your First Program

If programming using the Arduino software, the appropriate board files should be downloaded using preferences and boards manager.

Then the correct board must be selected on the board’s menu.

Since the built-in LED is on pin 13, just like the Arduino, the basic blink sketch will work on the Blue Pill.