My code is correct for push button ?

[CG3]

Thank you for helping and checking in advance:

LED on and Off working well, without if code

I am using

https://os.mbed.com/platforms/ST-Nucleo-L496ZG-P/#board-pinout

according

https://www.st.com/resource/en/user_manual/um2179-stm32-nucleo144-boards-mb1312-stmicroelectronics.pdf

User push button connect to PC13

in while (1) loop I add this if HAL code,

set PC13 Pull-Up and Input

Am i miss any setting?

 if(HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_13) == 0)

   {

  // LED ON

    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7|GPIO_PIN_14, GPIO_PIN_SET);

    HAL_Delay(1500);

    // LED OFF

    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7|GPIO_PIN_14, GPIO_PIN_RESET);

    HAL_Delay(1500);

   }

[MM..1]

Any GPIO require before use init code. And buttons on nucleo i mean push to 1 not 0.

What your code do ?

[Karl Yamashita]

The user push button connected to PC13 is active high.

if(HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_13) == GPIO_PIN_SET)

{

...

}

[Foued_KH]

Hello @CG3​ ,

You can try :

/* Wait for User push-button press before starting */
while (HAL_GPIO_ReadPin(GPIOC,GPIO_PIN_13) != GPIO_PIN_RESET)
  {
  }
/* Wait for User push-button release before starting */
    while (HAL_GPIO_ReadPin(GPIOC,GPIO_PIN_13) != GPIO_PIN_SET)
  {
  }
 
  // LED ON
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7|GPIO_PIN_14, GPIO_PIN_SET);
    HAL_Delay(1500);
    // LED OFF
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7|GPIO_PIN_14, GPIO_PIN_RESET);
    HAL_Delay(1500);

Foued

[Karl Yamashita · Accepted solution]

@CG3​ It looks like you just want to blink the LED while the push button is pressed but doing it in a while loop is blocking, so you can't do any other tasks.

So instead use EXTI on PC13

Then enable interrupts in NVIC

 

Then set the GPIO mode for interrupt mode on both Rising and falling edge

 

Then follow this YouTube video below on how to debounce a push button and also blink an LED all without using blocking code. So even if you are pressing and holding the button, the LED can be blinking while you can do other tasks like parse UART messages, communicate with I2C devices, etc.

There are a handful of examples that I show even counting button presses. You can create unique tasks and a lot more if you have a vivid imagination.

Debounce a push button using a timercallback

[CG3]

Great and thank you for helping

Yes I am really new and try to learn it step by step

I just understand

 if(HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_13) == 1)

will on/off after i push blue button and

 if(HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_13) == 0)

stop on/off only while i continue pushing it.

[CG3]

@Community member​ @KHALSI_Foued​ @MM..1​ thank you for helping