Blue Pill – STM32F103C8 Microcontroller development Board. How to program Blue Pill with Arduino IDE?

What is a Blue Pill board?

Unlike, the famous Arduino UNO board, the Blue Pill is a high-performance ARM Cortex-M3 32-bit microcontroller development board that works at a maximum operating frequency of 72MHz. As you already know that Arduino UNO board has some limitations when it comes to more complex projects because of its limited Input/Output pins, low-resolution ADC, slower PWM speed and fewer interrupt pins. These limitations can be overcome by using this Blue Pill board. It has more input/output pins, 12-bit ADCs, more external interrupt pins, higher PWM speed, and many more features. The Blue Pill board has more than one I2C, UART, and SPI port, which helps in communication with other devices way faster than that of the Arduino UNO board. It has lots of I/O pins which make it easier to connect more sensors, modules, and other electronic components to the board. In order to program this Blue Pill board, we will use the same Arduino IDE software and will use the same sets of instructions that we use for programming the Arduino UNO board. 

Specifications of the Blue Pill Board

• Microcontroller Name: STM32F103C8T6
• Maximum Frequency: 72MHz
• Flash memory: 64 or 128 Kb
• SRAM: 20Kb
• Input voltage: 2-3.3V DC
• 16 channels ADC
• I/O Ports: 37
• Timers: 7
• Two I2C ports
• Three UART Ports
• TWO SPI ports
• CAN interface

Applications of the Blue Pill Board

• Multi-rotors
• Robotics and automation
• Sensor development
• Rapid prototyping
• Consumer products

Blue Pill Vs Arduino UNO

Specification	Blue Pill	Arduino UNO
Processor	STM32F103C8T6	Atmega328P
Architecture	ARM Cortex-M3 32-bit RISC	AVR 8-bit RISC
Operating Frequency	72MHz	16MHz
Operating Voltage	5V DC	3.3V DC
UART Port	3	1
SPI Port	2	1
I2C Port	2	1
Digital I/O Pins	37	14
Analog pins	10	8

Blue Pill Board configuration

STM32F103C8T6: This is the main microcontroller IC used by the Blue Pill board.

MicroUSB connector: Used for connecting the board to the laptop.

Reset button: Used for resetting the board.

8MHz Crystal: This crystal is used by the main STM32 microcontroller.

32.768KHz Oscillator: This oscillator is for Real-time Clock(RTC).

Power Status LED: This LED is used for indicating power.

Built-in LED: This LED is connected to pin PC13(Arduino mapped pin 32).

BOOT selector: These pins are used for selecting between the BOOT1 and BOOT0. For BOOT0 connect the jumpers to top pins and for selecting BOOT1, connect the jumpers to the bottom pins. If BOOT0 is selected, when you reset the board or give power to the board the code will remain stored on the board. If BOOT1 is selected, when you reset the board or give power to the board the previous program stored on the board gets erased.

SWD Interface: Used for programming and debugging using ST-Link

Pin configuration of the Blue Pill Board

PIN Number	Board Pins	Arduino Pins	Other pin uses	PWM Pins	ADC Pins
1	PB12	28	SS2
2	PB13	29	SCK2
3	PB14	30	MISO2
4	PB15	31	MOSI2
5	PA8	8		PWM
6	PA9	9	TX1	PWM
7	PA10	10	TX2	PWM
8	PA11	11	USB-
9	PA12	12	USB+
10	PA15	15
11	PB3	19
12	PB4	20
13	PB5	21
14	PB6	22	SCL1	PWM
15	PB7	23	SDA2	PWM
16	PB8	24		PWM
17	PB9	25		PWM
18	5V
19	GND
20	3.3V
21	VBAT
22	PC13	32	LED
23	PC14	33
24	PC15	34
25	PA0	0		PWM	ADC0
26	PA1	1		PWM	ADC1
27	PA2	2	TX2	PWM	ADC2
28	PA3	3	RX2	PWM	ADC3
29	PA4	4	SS1		ADC4
30	PA5	5	SCK1		ADC5
31	PA6	6	MISO1	PWM	ADC6
32	PA7	7	MOSI1	PWM	ADC7
33	PB0	16		PWM	ADC8
34	PB1	17		PWM	ADC9
35	PB10	26	TX3/ SDA2
36	PB11	27	RX3/ SCL2
37	RESET
38	3.3V
39	GND
40	GND
41	3.3V
42	PA13	34	JTMS/ SWDIO
43	PA14	37	JTCK/ SWCLK
44	GND
45	GND
46	PB2	18	BOOT1
47	3.3V
48	3.3v
49			BOOT0
50	GND

Important note: While writing the Arduino code, we will be using the pin number as mentioned in the Arduino pins column that is highlighted with blue color.

Programming the Blue Pill board with Arduino IDE

Step1: Get ready with your Blue Pill Board.

Step2: Power the Blue Pill board with a  USB power supply of 5 volts.

Step3: Connect the USB to UART converter as shown in the diagram.

Step4: Select 3.3v mode in USB to the serial converter by connecting the jumpers as shown in the diagram.

Step5: Connect the USB to UART converter to the laptop.

Step6: Open the Arduino IDE

Step7: Click on the file option

Step8: Click on the Preferences

Step9: Paste this link in the additional board manager URLs : http://dan.drown.org/stm32duino/package_STM32duino_index.json

Step10: Click on the OK

Step11: Click on the tools

Step12: Click on the Board

Step13: Click on the Board manager and wait for some time

Step14: Scroll down and find the STM32F1xx/GD32F1xx Board and then click on install. Wait for some time till the board is downloaded.

Step15: Close the board manager if you got this message

Make sure your Blue Pill board is connected to the laptop with the help of a USB to UART converter. Now, we will upload our first LED blinking code to the board. Paste this code in Arduino IDE. Connect an LED to the A6 pin of the board as shown in the diagram. In terms of Arduino mapped pins, A6 pin of the Blue Pill board is a D6 pin in Arduino, you can refer to the pin configuration table for this. While writing your code for the Blue pill board, you just have to use the pin number as per the Arduino mapped pins. Rest all the commands are the same.

void setup()
{
pinMode(6,OUTPUT);
}
void loop()
{
digitalWrite(6,HIGH);
delay(1000);
digitalWrite(6,LOW);
delay(1000);
}

Circuit diagram for connecting an LED to the Blue Pill board

In order to upload the code to the Blue Pill board follow the following steps.

Step1: Click on the tools and then click on board

Step2: Click on the STM32F1 boards

Step3: Click on the Generic STM32F103C series

Step4: Select the port

Step5: Click on the upload button and after uploading the LED will start blinking.

I hope, you have successfully integrated your Blue Pill board with Arduino IDE. If you have any doubt, you can comment below or you can email us.