STM32之红外接收
摘自:http://blog.****.net/feilusia/article/details/53319896
一、简介
本文介绍如何在STM32上使用红外接收头接收红外信号。
其中,红外协议采用为最常见的NEC协议。
二、实验平台
库版本:STM32F10x_StdPeriph_Lib_V3.5.0
编译软件:MDK4.53
硬件平台:STM32开发板(主芯片stm32f103c8t6)
仿真器:JLINK
三、版权声明
博主:甜甜的大香瓜
声明:喝水不忘挖井人,转载请注明出处。
原文地址:http://blog.****.NET/feilusia
联系方式:[email protected]
香瓜BLE之CC2541群:127442605
香瓜BLE之CC2640群:557278427
1、硬件原理
答:
1)接收管元器件
上图的引脚从左到右依次为:OUT(空闲时为高电平,接收到载波时为低电平)、GND、VCC。
电压范围为2.7V~5.5V。
附淘宝链接:
https://detail.tmall.com/item.htm?spm=a1z10.3-b.w4011-3079905380.37.ZS9LXo&id=14265901312&rn=9fa50b1d19ad40efa6f149c454e32cfa&abbucket=14
2)硬件原理图
如上图,红外接收引脚接到PB3,PB3为JTAG使用引脚,因此在代码中要注意将引脚功能切换回普通IO口。
2、本文中红外接收的流程是如何的?
答:
1)配置红外接收引脚PB3为IO上拉中断方式。
2)当红外接收头接收到红外遥控器发出的载波信号时,PB3被拉低,代码进入中断服务函数,并依次判断时序是否满足:引导码、用户码、用户反码、键码、键码反码、停止位。
如果时序正确,则获得键值。如果时序不正确,则将此数据过滤。
六、实验步骤
注:下面的步骤为主要步骤,并不是所有步骤,编译有错误的地方请自行修改。
1、编写并添加红外接收的驱动
1)编写驱动GUA_Infrared_Receiver.c(存放在“……\HARDWARE”)
- //******************************************************************************
- //name: GUA_Infrared_Receiver.c
- //introduce: 红外传感器接收驱动
- //author: 甜甜的大香瓜
- //email: [email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.12.29
- //******************************************************************************
- #include "stm32f10x.h"
- #include "GUA_Infrared_Receiver.h"
- #include "GUA_SysTick.h"
- /*********************宏定义************************/
- #define TRUE 0
- #define FALSE 1
- //红外接收引脚
- //IO
- #define GUA_INFRARED_RECEIVER_PORT GPIOB
- #define GUA_INFRARED_RECEIVER_PIN GPIO_Pin_3
- #define GUA_INFRARED_RECEIVER_RCC RCC_APB2Periph_GPIOB
- //中断
- #define GUA_INFRARED_RECEIVER_EXTI_LINE EXTI_Line3
- #define GUA_INFRARED_RECEIVER_PORTSOURCE GPIO_PortSourceGPIOB
- #define GUA_INFRARED_RECEIVER_PINSOURCE GPIO_PinSource3
- /*********************外部变量************************/
- GUA_U32 gGUA_InfraredReceiver_Data = 0;
- /*********************内部函数************************/
- static void GUA_Infrared_Receiver_IO_Init(void);
- static GUA_U16 GUA_Infrared_Receiver_GetHighLevelTime(void);
- static GUA_U16 GUA_Infrared_Receiver_GetLowLevelTime(void);
- //******************************************************************************
- //name: GUA_Infrared_Receiver_IO_Init
- //introduce: 红外接收的IO初始化
- //parameter: none
- //return: none
- //author: 甜甜的大香瓜
- //email: [email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.12.29
- //******************************************************************************
- static void GUA_Infrared_Receiver_IO_Init(void)
- {
- //IO结构体
- GPIO_InitTypeDef GPIO_InitStructure;
- //失能JTAG和SWD在PB3上的功能使用
- GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);
- GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);
- //时钟使能
- RCC_APB2PeriphClockCmd(GUA_INFRARED_RECEIVER_RCC | RCC_APB2Periph_AFIO, ENABLE);
- //红外接收IO配置
- GPIO_InitStructure.GPIO_Pin = GUA_INFRARED_RECEIVER_PIN;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
- GPIO_Init(GUA_INFRARED_RECEIVER_PORT, &GPIO_InitStructure);
- }
- //******************************************************************************
- //name: GUA_Infrared_Receiver_Exti_Init
- //introduce: 红外接收的IO中断初始化
- //parameter: none
- //return: none
- //author: 甜甜的大香瓜
- //email: [email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.12.29
- //******************************************************************************
- static void GUA_Infrared_Receiver_Exti_Init(void)
- {
- EXTI_InitTypeDef EXTI_InitStructure;
- //中断配置
- EXTI_ClearITPendingBit(GUA_INFRARED_RECEIVER_EXTI_LINE);
- GPIO_EXTILineConfig(GUA_INFRARED_RECEIVER_PORTSOURCE, GUA_INFRARED_RECEIVER_PINSOURCE);
- EXTI_InitStructure.EXTI_Line = GUA_INFRARED_RECEIVER_EXTI_LINE;
- EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
- EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
- EXTI_InitStructure.EXTI_LineCmd = ENABLE;
- EXTI_Init(&EXTI_InitStructure);
- }
- //******************************************************************************
- //name: GUA_Infrared_Receiver_Init
- //introduce: 红外接收初始化
- //parameter: none
- //return: none
- //author: 甜甜的大香瓜
- //email: [email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.12.29
- //******************************************************************************
- void GUA_Infrared_Receiver_Init(void)
- {
- //初始化IO
- GUA_Infrared_Receiver_IO_Init();
- //初始化中断配置
- GUA_Infrared_Receiver_Exti_Init();
- }
- //******************************************************************************
- //name: GUA_Infrared_Receiver_GetHighLevelTime
- //introduce: 红外接收获取高电平维持时间
- //parameter: none
- //return: nNum:返回20us的个数
- //author: 甜甜的大香瓜
- //email: 897503845[email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.12.29
- //******************************************************************************
- static GUA_U16 GUA_Infrared_Receiver_GetHighLevelTime(void)
- {
- GUA_U16 nGUA_Num = 0;
- //判断是否一直为高电平
- while(GPIO_ReadInputDataBit(GUA_INFRARED_RECEIVER_PORT, GUA_INFRARED_RECEIVER_PIN) == Bit_SET)
- {
- //超时超时溢出
- if(nGUA_Num >= 250)
- {
- return nGUA_Num;
- }
- //计延时20us的次数
- nGUA_Num++;
- //延时
- GUA_Delay_Us(17);
- }
- return nGUA_Num;
- }
- //******************************************************************************
- //name: GUA_Infrared_Receiver_GetLowLevelTime
- //introduce: 红外接收获取低电平维持时间
- //parameter: none
- //return: nNum:返回20us的个数
- //author: 甜甜的大香瓜
- //email: [email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.12.29
- //******************************************************************************
- static GUA_U16 GUA_Infrared_Receiver_GetLowLevelTime(void)
- {
- GUA_U16 nGUA_Num = 0;
- //判断是否一直为低电平
- while(GPIO_ReadInputDataBit(GUA_INFRARED_RECEIVER_PORT, GUA_INFRARED_RECEIVER_PIN) == Bit_RESET)
- {
- //超时超时溢出
- if(nGUA_Num >= 500)
- {
- return nGUA_Num;
- }
- //计延时20us的次数
- nGUA_Num++;
- //延时
- GUA_Delay_Us(17);
- }
- return nGUA_Num;
- }
- //******************************************************************************
- //name: GUA_Infrared_Receiver_Process
- //introduce: 红外接收的处理函数
- //parameter: none
- //return: GUA_INFRARED_RECEIVER_OK or GUA_INFRARED_RECEIVER_ERROR
- //author: 甜甜的大香瓜
- //email: [email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.12.29
- //******************************************************************************
- GUA_U8 GUA_Infrared_Receiver_Process(void)
- {
- GUA_U16 nGUA_Time_Num = 0;
- GUA_U8 nGUA_Data = 0;
- GUA_U8 nGUA_Byte_Num = 0;
- GUA_U8 nGUA_Bit_Num = 0;
- //接收引导码9ms的低电平,过滤无用信号>10ms或<8ms
- nGUA_Time_Num = GUA_Infrared_Receiver_GetLowLevelTime();
- if((nGUA_Time_Num >= 500) || (nGUA_Time_Num <= 400))
- {
- return GUA_INFRARED_RECEIVER_ERROR;
- }
- //接收引导码4.5ms的高电平,过滤无用信号>5ms或<4ms
- nGUA_Time_Num = GUA_Infrared_Receiver_GetHighLevelTime();
- if((nGUA_Time_Num >= 250) || (nGUA_Time_Num <= 200))
- {
- return GUA_INFRARED_RECEIVER_ERROR;
- }
- //接收后4字节数据
- for(nGUA_Byte_Num = 0; nGUA_Byte_Num < 4; nGUA_Byte_Num++)
- {
- //接收每字节8位数据
- for(nGUA_Bit_Num = 0; nGUA_Bit_Num < 8; nGUA_Bit_Num++)
- {
- //接收每bit的前0.56ms的低电平,过滤无用信号>1.2ms或<0.40ms
- nGUA_Time_Num = GUA_Infrared_Receiver_GetLowLevelTime();
- if((nGUA_Time_Num >= 60) || (nGUA_Time_Num <= 20))
- {
- return GUA_INFRARED_RECEIVER_ERROR;
- }
- //接收每bit的后高电平时长:高电平数据,1.68ms(1.2ms~2.0ms),低电平数据,0.56ms(0.2ms~1ms),过滤其他无用信号
- nGUA_Time_Num = GUA_Infrared_Receiver_GetHighLevelTime();
- if((nGUA_Time_Num >=60) && (nGUA_Time_Num < 100))
- {
- nGUA_Data = 1;
- }
- else if((nGUA_Time_Num >=10) && (nGUA_Time_Num < 50))
- {
- nGUA_Data = 0;
- }
- else
- {
- return GUA_INFRARED_RECEIVER_ERROR;
- }
- //保存数据
- gGUA_InfraredReceiver_Data <<= 1;
- gGUA_InfraredReceiver_Data |= nGUA_Data;
- }
- }
- return GUA_INFRARED_RECEIVER_OK;
- }
2)编写驱动头文件GUA_Infrared_Receiver.h(存放在“……\HARDWARE”)
- //******************************************************************************
- //name: GUA_Infrared_Receiver.h
- //introduce: 红外传感器接收驱动的头文件
- //author: 甜甜的大香瓜
- //email: [email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.12.29
- //******************************************************************************
- #ifndef _GUA_INFRARED_RECEIVER_H_
- #define _GUA_INFRARED_RECEIVER_H_
- /*********************宏定义************************/
- #ifndef GUA_U8
- typedef unsigned char GUA_U8;
- #endif
- #ifndef GUA_8
- typedef signed char GUA_8;
- #endif
- #ifndef GUA_U16
- typedef unsigned short GUA_U16;
- #endif
- #ifndef GUA_16
- typedef signed short GUA_16;
- #endif
- #ifndef GUA_U32
- typedef unsigned long GUA_U32;
- #endif
- #ifndef GUA_32
- typedef signed long GUA_32;
- #endif
- #ifndef GUA_U64
- typedef unsigned long long GUA_U64;
- #endif
- #ifndef GUA_64
- typedef signed long long GUA_64;
- #endif
- #define GUA_INFRARED_RECEIVER_OK 0
- #define GUA_INFRARED_RECEIVER_ERROR 1
- #define GUA_INFRARED_RECEIVER_KEY1 0x00FF00FF
- #define GUA_INFRARED_RECEIVER_KEY2 0x00FF01FE
- #define GUA_INFRARED_RECEIVER_KEY3 0x00FF02FD
- #define GUA_INFRARED_RECEIVER_KEY4 0x00FF03FC
- /*********************外部变量************************/
- extern GUA_U32 gGUA_InfraredReceiver_Data;
- /*********************外部函数声明************************/
- extern void GUA_Infrared_Receiver_Init(void);
- extern GUA_U8 GUA_Infrared_Receiver_Process(void);
- #endif
3)工程中添加GUA_Infrared_Receiver.c
4)在MDK设置中添加驱动源文件路径
2、设置NVIC中断优先级(GUA_NVIC.c的GUA_NVIC_Init中)
- //红外接收
- GUA_NVIC_Config(NVIC_PriorityGroup_2, EXTI3_IRQn, 2, 2, ENABLE);
- #include "GUA_Infrared_Receiver.h"
2)编写中断服务函数
- //******************************************************************************
- //name: EXTI3_IRQHandler
- //introduce: 红外接收的处理函数
- //parameter: none
- //return: none
- //author: 甜甜的大香瓜
- //email: [email protected]
- //QQ group 香瓜单片机之STM8/STM32(164311667)
- //changetime: 2016.11.21
- //******************************************************************************
- void EXTI3_IRQHandler(void)
- {
- //红外
- if(EXTI_GetITStatus(EXTI_Line3) != RESET)
- {
- //接收红外数据正确
- if(GUA_Infrared_Receiver_Process() == GUA_INFRARED_RECEIVER_OK)
- {
- function = FUNC_INFRARED_RECEIVER_EVENT;
- }
- //清除标志位
- EXTI_ClearITPendingBit(EXTI_Line3);
- }
- }
4、在应用层中调用
1)添加头文件(main.c中)
- #include "GUA_Infrared_Receiver.h"
2)添加驱动初始化代码(main.c的main函数中)
- //红外接收初始化
- GUA_Infrared_Receiver_Init();
3)添加测试代码
①写红外接收处理事件(main.c的main函数中)
- //红外接收处理
- case FUNC_INFRARED_RECEIVER_EVENT:
- {
- //键值处理
- switch(gGUA_InfraredReceiver_Data)
- {
- //红外按键1
- case GUA_INFRARED_RECEIVER_KEY1:
- {
- break;
- }
- //红外按键2
- case GUA_INFRARED_RECEIVER_KEY2:
- {
- break;
- }
- //红外按键3
- case GUA_INFRARED_RECEIVER_KEY3:
- {
- break;
- }
- //红外按键4
- case GUA_INFRARED_RECEIVER_KEY4:
- {
- break;
- }
- //其他
- default:
- {
- break;
- }
- }
- //返回空闲状态
- function = FUNC_IDLE_EVENT;
- break;
- }
②写红外处理事件宏(main.h中)
- //主轮询的宏
- #define FUNC_IDLE_EVENT 0x00 //空闲
- #define FUNC_INFRARED_RECEIVER_EVENT 0x16 //红外接收处理
七、注意事项
暂无。
八、实验结果
仿真并设置断点在红外接收处理事件中,全速运行。
当遥控器发送0x00FF00FF的键值时,代码会停止在断点处,并且gGUA_InfraredReceiver_Data的值为0x00FF00FF。