一、接线

旋转编码器，旋钮会不断接触断开触点产生电波。 由于两个电波之间相差90°，即为正交波，一个电波处于高电平时另一个处于低电平，所以可以用来判断旋转方向。

二、代码

复制粘贴4-1的工程文件，重命名为“5-2 旋转编码器计次”，在“Hardware”文件夹右键新建“Encoder.c”及“Encoder.h”，注意文件路径。

Encoder.c：

#include "stm32f10x.h"                  // Device header

int16_t Encoder_Count;

void Encoder_Init(void)
{
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStruture;
	GPIO_InitStruture.GPIO_Mode = GPIO_Mode_IPU;
	GPIO_InitStruture.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
	GPIO_InitStruture.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOB,&GPIO_InitStruture);
	
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource0);
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource1);
	
	EXTI_InitTypeDef EXTI_InitStructure;
	EXTI_InitStructure.EXTI_Line = EXTI_Line0 | EXTI_Line1;
	EXTI_InitStructure.EXTI_LineCmd = ENABLE;
	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
	EXTI_Init(&EXTI_InitStructure);
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	
	NVIC_InitTypeDef NVIC_InitStructure;
	NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_Init(&NVIC_InitStructure);
	
	NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
	NVIC_Init(&NVIC_InitStructure);
}

int16_t Encoder_Get(void)
{
	int16_t Temp;
	Temp = Encoder_Count;
	Encoder_Count = 0;
	return Temp;
}
	
void EXTI0_IRQHandler(void)
{
	if (EXTI_GetITStatus(EXTI_Line0)  == SET)
	{
		if (GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_1) == 0)
		{
			Encoder_Count--;
		}
		EXTI_ClearITPendingBit(EXTI_Line0);
	}
}

void EXTI1_IRQHandler(void)
{
	if (EXTI_GetITStatus(EXTI_Line1)  == SET)
	{
		if (GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_0) == 0)
		{
			Encoder_Count++;
		}
		EXTI_ClearITPendingBit(EXTI_Line1);
	}   
}

 NVIC_InitStructure可以复用，所以这里只定义一个即可使用两个中断。

Encoder.h：

#ifndef __ENCODER_H
#define __ENCODER_H

void Encoder_Init(void);
int16_t Encoder_Get(void);


#endif

main.c：

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Encoder.h"

int16_t Num;

int main(void)
{
	OLED_Init();
	Encoder_Init();
	
	OLED_ShowString(1,1,"Num:");

	
	while(1)                                                                                                                                                                                                  
	{   
		Num += Encoder_Get();
		OLED_ShowSignedNum(1,5,Num,5);
	}
}