基于STM32F0系列单片机的红外遥控调试
红外遥控原理分析
遥控 ：NEC 编码 960nm的波长 晶振为455KHZ，对应的发射频率(载波频率)为38KHZ，
遥控ID为0(即系统识别码)，反码为255，不同的遥控ID有可能不一样。
遥控码由三部分组成
1、leader code 9ms的高电平 + 4.5ms 的低电平
2、系统识别码 区别不同的红外遥控设备
3、操作码 8bit操作码和8bit的操作反码组成
发送方的电平跟接收方解调出来的电平是反向的。
红外接收头接收到遥控器的信号后，解码出后的数据格式如下：
写程序即根据这个信号的格式来写。
__________________ _______ _ _ _ _ _ _ _ _ ____ ____ ____ ____ ____ ____ ____ ____ ___________________________________ _______ ___________________________________________________________
|_____________| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |_| |x x x x x x x x|x x x x x x x x| |_____________| |_|
|<- 9ms ->|<4.5ms>|
|----leader code------|-----custom code 8bit----------|-----------------custom code' 8bit---------------------| key data 8bit |key data'8bit |<---------------40ms---------------><----9ms-----><2.1ms>--|--------------- 此时的高电平超过40ms,然后出现9ms的低电平，2.1ms的高电平 连发码----------------
0和1均以0.56ms的低电平开始(实际测量是500us的样子)，不同的是后面出现的高电平，
如果高电平是0.56ms(实际测量是500us的样子)，则表示0，如果高电平是1.68ms(0.56*3=1.68)则表示1
0.56ms:|_|
_ _ _
0: |_| |_| |
_ ____ ____
1: |_| |_| |_
写代码的时候只需要检测高电平的时间即可。
以下时间都是通过示波器实际测量所得。
引导码的高电平：4.5ms
0的高电平 ：0.56ms(实测0.5ms的样子)
1的高电平 ：1.68ms
连发码的高电平：2.1ms
NEC码分析
代码展示：
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* © Copyright (c) 2020 STMicroelectronics.
* All rights reserved.
*
* This software component is licensed by ST under BSD 3-Clause license,
* the "License"; You may not use this file except in compliance with the
* License. You may obtain a copy of the License at:
* opensource.org/licenses/BSD-3-Clause
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "stdio.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define IR_IN HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_0)
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
uint32_t Remote_Order = 0;
uint8_t Remote_Count = 0 ;
uint8_t Remote_Reday = 0 ;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
uint8_t Pulse_Width_Check(void);
uint8_t Remote_Process(void);
void delay_us(int32_t nus)
{
int32_t temp;
SysTick->LOAD = nus*6 ; //32MHz
SysTick->VAL=0X00;//清空计数
SysTick->CTRL=0X01;//使能，减到零是无动作，采用外部时钟源
do
{
temp=SysTick->CTRL;//读取当前倒计时
}
while((temp&0x01)&&(!(temp&(1<<16))));//等待时间到达
SysTick->CTRL=0x00; //关闭计数
SysTick->VAL =0X00; //清空计数
}
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
HAL_GPIO_TogglePin(red_GPIO_Port,red_Pin);
// printf("order-code \r\n");
if(Remote_Reday)
{
uint8_t key = Remote_Process();
printf("order-code = %08X , key-code = %02X \r\n",Remote_Order,key);
}
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
/** Initializes the CPU, AHB and APB busses clocks
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL12;
RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV1;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB busses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
{
Error_Handler();
}
PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART1;
PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK1;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
#ifdef __GNUC__
/* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
/**
* @brief Retargets the C library printf function to the USART.
* @param None
* @retval None
*/
PUTCHAR_PROTOTYPE
{
/* Place your implementation of fputc here */
/* e.g. write a character to the EVAL_COM1 and Loop until the end of transmission */
HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);
return ch;
}
// 脉冲处理
uint8_t Pulse_Width_Check(void)
{
uint8_t t=0;
while(IR_IN == GPIO_PIN_SET)
{
t ++ ;
delay_us(20);
if(t==250) return t;
}
return t;
}
// 外部中断的回调函数
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
uint8_t res = 0 ;
uint8_t OK = 0;
uint8_t temp = 0;
if(GPIO_Pin & GPIO_PIN_0)
{
while(1)
{
if(IR_IN == GPIO_PIN_SET)
{
res = Pulse_Width_Check(); // 脉宽测量
if(res == 250) break;
else if(res >= 200 && res < 250) OK = 1;
else if(res >= 85 && res < 200)
{
Remote_Reday = 1;
Remote_Count ++;
break;
}
else if(res >= 50 && res < 85) temp = 1;
else if(res >= 10 && res < 50) temp = 0;
if(OK)
{
Remote_Order <<=1;
Remote_Order += temp;
Remote_Count = 0;
}
}
}
}
}
// 解码处理
uint8_t Remote_Process(void)
{
uint8_t t1 ,t2 ;
t1 = Remote_Order >> 24 ;
t2 = (Remote_Order >> 16) & 0xFF ;
Remote_Reday = 0;
if(t1 ==(uint8_t) ~t2)
{
t1 = Remote_Order >> 8;
t2 = Remote_Order ;
if(t1 ==(uint8_t) ~ t2) return t1;
}
return 0;
}
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(char *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
串口打印：
接受端波形图：
