写一个stm32关于红外线接受的程序
时间: 2023-08-11 07:05:27 浏览: 45
以下是一个基本的 stm32 红外线接收程序,使用了 TIM2 定时器和 EXTI 外部中断:
```c
#include "stm32f10x.h"
#define IR_PIN GPIO_Pin_0
#define IR_GPIO GPIOA
#define IR_EXTI EXTI_Line0
#define IR_EXTI_PORT_SOURCE GPIO_PortSourceGPIOA
#define IR_EXTI_PIN_SOURCE GPIO_PinSource0
#define IR_TIM TIM2
volatile uint16_t irValue = 0;
void IR_TIM_Config(void) {
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_TimeBaseStructure.TIM_Period = 8999; // 90us
TIM_TimeBaseStructure.TIM_Prescaler = 71; // 1MHz
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(IR_TIM, &TIM_TimeBaseStructure);
TIM_Cmd(IR_TIM, ENABLE);
}
void IR_EXTI_Config(void) {
GPIO_InitTypeDef GPIO_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
GPIO_InitStructure.GPIO_Pin = IR_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(IR_GPIO, &GPIO_InitStructure);
GPIO_EXTILineConfig(IR_EXTI_PORT_SOURCE, IR_EXTI_PIN_SOURCE);
EXTI_InitStructure.EXTI_Line = IR_EXTI;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void EXTI0_IRQHandler(void) {
static uint16_t lastValue = 0;
uint16_t duration = (uint16_t)(IR_TIM->CNT);
IR_TIM->CNT = 0;
if (duration < 10000) { // ignore noise
if (duration > 1000 && duration < 2000) { // start bit
irValue = 0;
} else if (duration > 400 && duration < 800) { // 0 bit
irValue = (irValue << 1) & 0xFF;
} else if (duration > 1200 && duration < 1600) { // 1 bit
irValue = ((irValue << 1) | 0x01) & 0xFF;
} else { // invalid bit
irValue = lastValue; // use previous value
}
lastValue = irValue;
}
EXTI_ClearITPendingBit(IR_EXTI);
}
int main(void) {
IR_TIM_Config();
IR_EXTI_Config();
while(1) {
// do something with irValue
}
}
```
此程序可以接收 NEC 协议的红外线信号,使用了 TIM2 定时器和 EXTI 外部中断来计时和捕获信号。当接收到有效的红外线信号时,会将信号值存储在 `irValue` 变量中,可以在主函数中使用该变量来执行相应的操作。
需要注意的是,此程序只是一个简单的红外线接收例程,实际使用时需要根据具体的应用场景进行修改和优化。