Unable to Use Serial2 and Serial3

[Shubham916701]

Hello,

I have been using the Arduino IDE for programming controllers from Atmel, esp, and teensy.
Now trying my hands on STM32 Blue Pill.

I have an application for which I will need to use the 3 Hardware Serial Ports of the Bluepill.
Am using this image for reference.

https://lh3.googleusercontent.com/YxZFvsHzIxhZSfSpUbmADkKbx6mwlExshpYgs4anPNOnYkqsS9kp_JdcWuecbrtlW8vNSP9jKElkvYGaOBZWNlRFAbZnaJZCIfaqqEVt7s7BccuJrthHiCRHXVz-HpqFAKAYhT1UsVWsFwtnaQ

The Board selection is shown below.

When I use Serial.begin(9600) or Serial1.begin(9600), the code gets compiled without any errors.
Moving ahead, when I use Serial2.begin(9600), the compilation ends with errors as shown here.

The error occurs when i try to use Serial2.
I need help in fixing what am doing wrong here.

Looking forward to a Saviour.

[fpistm]

Hi @Shubham916701
You can refer to https://github.com/stm32duino/wiki/wiki/API#hardwareserial

As stated:

By default, only one Serialx instance is available mapped to the generic Serial name.

For BluePill by default Serial instance is mapped to Serial1:

Arduino_Core_STM32/variants/STM32F1xx/F103C4T_F103C6(T-U)/variant_BLUEPILL_F103C6.h

Lines 125 to 137 in 4e9dae5

	// UART Definitions
	#ifndef SERIAL_UART_INSTANCE
	#define SERIAL_UART_INSTANCE 1
	#endif
	// Default pin used for generic 'Serial' instance
	// Mandatory for Firmata
	#ifndef PIN_SERIAL_RX
	#define PIN_SERIAL_RX PA10
	#endif
	#ifndef PIN_SERIAL_TX
	#define PIN_SERIAL_TX PA9
	#endif

To use Serial2, you have to declare them:
HardwareSerial Serial2(PA3, PA2);

Anyway STM32F103C6 has only 2 USART not 3. Maybe you got a BluePill F103C8?
In that case:
HardwareSerial Serial2(PA3, PA2);
HardwareSerial Serial2(PB11, PB10);

[Shadrack-N]

awesome, thanks