stm32按键控制led的pwm的具体代码
时间: 2024-03-11 22:39:10 浏览: 18
以下是一个基于STM32的按键控制LED的PWM代码示例:
首先,需要在代码中定义使用的引脚以及相关的寄存器:
```
#define LED_PIN GPIO_Pin_0
#define LED_PORT GPIOA
#define KEY_PIN GPIO_Pin_1
#define KEY_PORT GPIOA
#define RCC_AHBPeriph_GPIOA RCC_AHBPeriph_GPIOA
#define RCC_APB1Periph_TIM3 RCC_APB1Periph_TIM3
#define TIM3_CH1_PIN GPIO_Pin_6
#define TIM3_CH1_PORT GPIOA
#define TIM3_CH1_PINSOURCE GPIO_PinSource6
#define TIM3_CH1_AF GPIO_AF_1
#define TIM3_PRESCALER 72
```
然后,需要在代码中初始化相关的GPIO和定时器:
```
void init_gpio(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
GPIO_InitStruct.GPIO_Pin = LED_PIN;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(LED_PORT, &GPIO_InitStruct);
GPIO_InitStruct.GPIO_Pin = KEY_PIN;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(KEY_PORT, &GPIO_InitStruct);
GPIO_PinAFConfig(TIM3_CH1_PORT, TIM3_CH1_PINSOURCE, TIM3_CH1_AF);
}
void init_timer(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
TIM_OCInitTypeDef TIM_OCInitStruct;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
TIM_TimeBaseInitStruct.TIM_Prescaler = TIM3_PRESCALER - 1;
TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInitStruct.TIM_Period = 2000 - 1;
TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStruct);
TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStruct.TIM_Pulse = 1000;
TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStruct);
TIM_Cmd(TIM3, ENABLE);
}
```
接下来,需要实现一个函数来读取按键状态:
```
int read_key(void)
{
if (GPIO_ReadInputDataBit(KEY_PORT, KEY_PIN) == 0)
{
return 1;
}
else
{
return 0;
}
}
```
最后,需要在主循环中实现按键控制LED的PWM:
```
int main(void)
{
init_gpio();
init_timer();
while (1)
{
if (read_key())
{
TIM_SetCompare1(TIM3, 1000);
}
else
{
TIM_SetCompare1(TIM3, 0);
}
}
}
```
上述代码中,按键的状态会被不断地读取,如果按键被按下,则LED的PWM占空比为50%(即1000/2000),否则PWM占空比为0。