[STM32F4-discovery development board review] Basic use of GPIO ports

jinglixixi

[STM32F4-discovery development board review] Basic use of GPIO ports [Copy link]

The GPIO port is the entry point for hardware development. To understand the basic usage of the GPIO port, you can start with the use of LED and KEY.

There are 2 LEDs and 1 KEY on the development board, and the circuit is shown in Figure 1 and Figure 2.

Figure 1 LED circuit

Figure 2 KEY circuit

From the figure, we can see that the connection relationship between it and the development board is:

LD3---PG13

LD4--- PG14

KEY--- PA0

When the LED is turned on, the corresponding pin is required to output a high level. For KEY, it is a high level when the key is pressed.

The function to implement LED and KEY initialization is:

void gpio_Init(void )
{
  GPIO_InitTypeDef  GPIO_InitStruct;
  __HAL_RCC_GPIOG_CLK_ENABLE();
  GPIO_InitStruct.Pin = GPIO_PIN_13|GPIO_PIN_14;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FAST;
  HAL_GPIO_Init(GPIOG, &GPIO_InitStruct);
  
  __HAL_RCC_GPIOA_CLK_ENABLE();
  GPIO_InitStruct.Pin = GPIO_PIN_0;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FAST;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

The main program to realize the button control of LED light on and off is:

int main(void)
{
    SystemClock_Config();
	gpio_Init();
	while (1)
    {
		   if(HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0)==1)
		   {
		         HAL_GPIO_WritePin(GPIOG, GPIO_PIN_13, GPIO_PIN_SET); 
		         HAL_GPIO_WritePin(GPIOG, GPIO_PIN_14, GPIO_PIN_SET); 
		   }
		   else
		   {
                 HAL_GPIO_WritePin(GPIOG, GPIO_PIN_13, GPIO_PIN_RESET);
                 HAL_GPIO_WritePin(GPIOG, GPIO_PIN_14, GPIO_PIN_RESET); 		
		   }
    }
}

After the program is compiled and downloaded, the result is shown in Figure 3, indicating that the program is effective.

Figure 3 Control effect

Later, the GPIO port will be used to realize the display drive of the OLED screen.

Jacktang

The GPIO port basically uses one button and two lights, which is easier to control.

jinglixixi

Jacktang posted on 2023-9-18 07:28 The GPIO port basically uses one button and two lights, which is easier to control

Haha, a towering building rises from the ground.

freebsder

Looking at this USB port, we can infer that this board should be more than 10 years old.

jinglixixi

freebsder posted on 2023-9-19 17:21 Looking at this USB port, we can infer that this board should be stored for more than 10 years

If it is older, it can be collected as an antique!!!