how to use extern "C"

[waaizkhan]

hi everyone want to use interrupt in main.c i am using extern "C" for this purpose but its couldn't compile

/* USER CODE BEGIN 4 */

extern "C" void TIM2_IRQHandler(void) {

// Handle update interrupts (update interrupt flag is set)

if (TIM2->SR & TIM_SR_UIF) {

// Reset the update interrupt flag

TIM2->SR &= ~(TIM_SR_UIF);

// Toggle the LED

HAL_GPIO_TogglePin(GPIOD, GPIO_PIN_14);

Flag_Angle = 1;

}

}

Error: L6200E: Symbol TIM2_IRQHandler multiply defined (by stm32f4xx_it.o and main.o).

also infinite while is executed just one time .

[Tesla DeLorean]

Don't think the issue is related to extern "C" usage.

The linker is complaining that you have two copies of the IRQ Handler's body function, both in stm32f4xx_it.c and main.c decide which one you want, and comment out the other.

Don't write TIM->SR with a RMW instruction, just WRITE the bit mask to clear the interrupt sources. See Reference Manual, read specific functionality of the register described there.

[waaizkhan]

thanks a lot can i use IRQ Handler in main.c instead of stm32f4xx_it.c if i comment it in stm32f4xx_it.c is it a right approach and why while infinite loop execute just one time .

[Tesla DeLorean]

You can put it in whatever source file you choose.

>>.. why while infinite loop execute just one time .

No idea what you're talking about, lack any real context, see no code presented with a while() loop

Code lacking appropriate handlers may dump into Default_Handler(), HardFault_Handler(), or Error_Handler()

If the interrupt rate is too high (say >400 KHz) the system may saturate and continually reenter the IRQHandler, and prevent foreground execution.

[turboscrew]

"extern C" is for C++. It tells the compiler that the function is extern and C instead of C++ (calling convention and name mangling).