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:
cpp
#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:
cpp
#ifndef __ENCODER_H
#define __ENCODER_H
void Encoder_Init(void);
int16_t Encoder_Get(void);
#endif
main.c:
cpp
#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);
}
}