The code of this article refers to the punctual atomic routine
Article directory
Experimental features
Routine source code: (main.c)
This experiment realizes the control of LED and BEEP through key input, and the main function code is in the external interrupt service function.
#include "sys.h"
#include "usart.h"
#include "delay.h"
#include "led.h"
#include "beep.h"
#include "key.h"
#include "exti.h"
/*********************************************************************************
___ _ _____ _____ _ _ _____ _____ _ __
/ _ \ | | |_ _|| ___|| \ | ||_ _|| ___|| | / /
/ /_\ \| | | | | |__ | \| | | | | |__ | |/ /
| _ || | | | | __| | . ` | | | | __| | \
| | | || |_____| |_ | |___ | |\ | | | | |___ | |\ \
\_| |_/\_____/\___/ \____/ \_| \_/ \_/ \____/ \_| \_/
* ******************************************************************************
* 正点原子 Pandora STM32L475 IoT开发板 实验5
* 外部中断实验 HAL库版本
* 技术支持：www.openedv.com
* 淘宝店铺：http://openedv.taobao.com
* 关注微信公众平台微信号："正点原子"，免费获取STM32资料。
* 广州市星翼电子科技有限公司
* 作者：正点原子 @ALIENTEK
* ******************************************************************************/
int main(void)
{
HAL_Init();
SystemClock_Config(); //初始化系统时钟为80M
delay_init(80); //初始化延时函数 80M系统时钟
uart_init(115200); //初始化串口，波特率为115200
LED_Init(); //初始化LED
BEEP_Init(); //初始化蜂鸣器
EXTI_Init(); //初始化外部中断
while(1)
{
printf("OK\r\n"); //打印OK提示程序运行
delay_ms(1000); //每隔1s打印一次
}
}
Code Analysis
HAL_Init()
HAL_Init()The definition is as follows: (see the notes for the specific functions implemented)
HAL_StatusTypeDef HAL_Init(void)
{
HAL_StatusTypeDef status = HAL_OK;
/* 配置 Flash 预取，指令缓存，数据缓存 */
/* 默认配置为：预存取关闭 指令缓存和数据缓存开启 */
#if (INSTRUCTION_CACHE_ENABLE == 0) // Flash开启预存取配置，能加速CPU代码的执行
__HAL_FLASH_INSTRUCTION_CACHE_DISABLE();
#endif /* INSTRUCTION_CACHE_ENABLE */
#if (DATA_CACHE_ENABLE == 0)
__HAL_FLASH_DATA_CACHE_DISABLE();
#endif /* DATA_CACHE_ENABLE */
#if (PREFETCH_ENABLE != 0)
__HAL_FLASH_PREFETCH_BUFFER_ENABLE();
#endif /* PREFETCH_ENABLE */
/* Set Interrupt Group Priority */
HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_2); // 配置 NVIC 优先级分组
/* Use SysTick as time base source and configure 1ms tick (default clock after Reset is MSI) */
if (HAL_InitTick(TICK_INT_PRIORITY) != HAL_OK) //初始化滴答定时器，时钟节拍设置为 1ms
{
status = HAL_ERROR;
}
else
{
/* Init the low level hardware */
HAL_MspInit(); // 低速的外设初始化，比如 GPIO、中断等的设置（使用 STM32CubeMx 生成代码时会将低速外设初始
// 代码当这类函数里，其他情况下可以忽略这个函数
}
/* Return function status */
return status;
}
HAL_InitTick()
tick timer clock tick initialization function
__weak HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)
{
HAL_StatusTypeDef status = HAL_OK;
/*Configure the SysTick to have interrupt in 1ms time basis*/
if (HAL_SYSTICK_Config(SystemCoreClock/1000UL) != 0U) // 系统时钟/1000，中断周期为 1ms
{
status = HAL_ERROR;
}
else
{
/*Configure the SysTick IRQ priority */
HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0); // 将滴答定时器的中断优先级设置为最高
}
/* Return function status */
return status;
}
SystemClock_Config()
SystemClock_Config()The function definition is as follows: (For the specific implementation of the function, see the comments, for reference only)
void SystemClock_Config(void)
{
HAL_StatusTypeDef ret = HAL_OK;
RCC_OscInitTypeDef RCC_OscInitStruct; // 定义振荡器初始化结构体变量
RCC_ClkInitTypeDef RCC_ClkInitStruct; // 定义时钟初始化结构体变量
__HAL_RCC_PWR_CLK_ENABLE(); // 使能电源控制时钟
/*Initializes the CPU, AHB and APB busses clocks*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE; // 将 HSE（外部高速时钟）作为时钟源
RCC_OscInitStruct.HSEState = RCC_HSE_ON; // 开启 HSE
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON; // 开启 PLL（锁相环）
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE; // 将 HSE 作为 PLL 的时钟源
RCC_OscInitStruct.PLL.PLLM = 1; // PLL-VCO 输入时钟分频系数，1 表示 2 分频（8 / 2 = 4M，本开发板外部晶振频率为 8MHz）
RCC_OscInitStruct.PLL.PLLN = 20; // PLL-VCO 输出时钟倍频系数，4 * 20 = 80M，即输出时钟频率为 80MHz
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7; // SAI 时钟的分频系数
RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2; // SDMMC1, RNG 和 USB 的时钟分频系数
RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2; // 主系统时钟的分频系数
ret = HAL_RCC_OscConfig(&RCC_OscInitStruct); //初始化时钟配置
if(ret != HAL_OK) while(1);
/*Initializes the CPU, AHB and APB busses clocks*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
| RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2; // 将所有时钟同时进行配置
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; // 将 PLL 作为系统时钟源
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; // AHB 不分频
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1; // APB1 不分频
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1; // APB2 不分频
ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4); // 配置时钟初始结构体变量，
//使用 Flash 延迟4，等待状态(延迟)的数量需要根据CPU时钟(HCLK)的频率和内部电压范围来选择，具体怎么
//选需要参考芯片手册
if(ret != HAL_OK) while(1);
/*Configure the main internal regulator output voltage*/
ret = HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1); //内部寄存器输出电压配置
// 下面是 HAL_PWREx_ControlVoltageScaling() 函数说明的部分内容：
//PWR_REGULATOR_VOLTAGE_SCALE1 Regulator voltage output range 1 mode, typical output voltage
// at 1.2 V, system frequency up to 80 MHz.
if(ret != HAL_OK) while(1);
}
delay_init()
The tick timer has HAL_Init()been initialized in , and the following function actually fac_usassigns a value (currently not involving the operating system, and other codes will not be studied for the time being).
static u32 fac_us = 0; //us延时倍乘数
/**
* @brief 初始化延迟函数,SYSTICK的时钟固定为AHB时钟
*
* @param SYSCLK 系统时钟频率
*
* @return void
*/
void delay_init(u8 SYSCLK)
{
#if SYSTEM_SUPPORT_OS //如果需要支持OS.
u32 reload;
#endif
HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);//SysTick频率为HCLK
fac_us = SYSCLK; //不论是否使用OS,fac_us都需要使用
#if SYSTEM_SUPPORT_OS //如果需要支持OS.
reload = SYSCLK; //每秒钟的计数次数 单位为K
reload *= 1000000 / delay_ostickspersec; //根据delay_ostickspersec设定溢出时间
//reload为24位寄存器,最大值:16777216,在80M下，约209.7ms左右
fac_ms = 1000 / delay_ostickspersec; //代表OS可以延时的最少单位
SysTick->CTRL |= SysTick_CTRL_TICKINT_Msk; //开启SYSTICK中断
SysTick->LOAD = reload; //每1/OS_TICKS_PER_SEC秒中断一次
SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; //开启SYSTICK
#else
#endif
}
EXTI_Init()
External interrupt interrupt initialization function, configure the external interrupt function of 4 keys.
/**
* @brief 外部中断初始化函数
*
* @param void
*
* @return void
*/
void EXTI_Init(void)
{
/*
KEY0 - PD10
KEY1 - PD9
KEY2 - PD8
WK_UP - PC13
*/
GPIO_InitTypeDef GPIO_Initure;
__HAL_RCC_GPIOC_CLK_ENABLE(); //开启GPIOC时钟
__HAL_RCC_GPIOD_CLK_ENABLE(); //开启GPIOD时钟
GPIO_Initure.Pin=GPIO_PIN_8 | GPIO_PIN_9 | GPIO_PIN_10 ; //PD8.9.10
GPIO_Initure.Mode=GPIO_MODE_IT_FALLING; //下降沿触发GPIO_MODE_IT_FALLING
GPIO_Initure.Pull=GPIO_PULLUP;
HAL_GPIO_Init(GPIOD,&GPIO_Initure);
GPIO_Initure.Pin=GPIO_PIN_13; //PC13
GPIO_Initure.Mode=GPIO_MODE_IT_RISING; //上升沿触发
GPIO_Initure.Pull=GPIO_PULLDOWN;
HAL_GPIO_Init(GPIOC,&GPIO_Initure);
//中断线8,9
HAL_NVIC_SetPriority(EXTI9_5_IRQn,2,0); //抢占优先级为2，子优先级为0
HAL_NVIC_EnableIRQ(EXTI9_5_IRQn); //使能中断线0
//中断线10,13
HAL_NVIC_SetPriority(EXTI15_10_IRQn,2,1); //抢占优先级为2，子优先级为1
HAL_NVIC_EnableIRQ(EXTI15_10_IRQn); //使能中断线13
}
Interrupt service related functions
Four keys are handled in EXTI9_5_IRQHandler()and EXTI15_10_IRQHandler()two interrupt functions respectively,
/**
* @brief EXTI9_5中断服务函数
*
* @param void
*
* @return void
*/
void EXTI9_5_IRQHandler(void)
{
HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_8);//调用中断处理公用函数
HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_9);//调用中断处理公用函数
}
/**
* @brief EXTI15_10中断服务函数
*
* @param void
*
* @return void
*/
void EXTI15_10_IRQHandler(void)
{
HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_10);//调用中断处理公用函数
HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_13);//调用中断处理公用函数
}
HAL_GPIO_EXTI_IRQHandler()It is the general interrupt processing function of GPIO. This function will first obtain the interrupt line number, then clear the interrupt, and finally call the interrupt callback function HAL_GPIO_EXTI_Callback().
/**
* @brief Handle EXTI interrupt request.
* @param GPIO_Pin Specifies the port pin connected to corresponding EXTI line.
* @retval None
*/
void HAL_GPIO_EXTI_IRQHandler(uint16_t GPIO_Pin)
{
/* EXTI line interrupt detected */
if(__HAL_GPIO_EXTI_GET_IT(GPIO_Pin) != 0x00u)
{
__HAL_GPIO_EXTI_CLEAR_IT(GPIO_Pin);
HAL_GPIO_EXTI_Callback(GPIO_Pin);
}
}
HAL_GPIO_EXTI_Callback()There is a definition in the HAL library, but it is a weak definition, just like other system interrupt service functions, as long as we rewrite the function, the function we rewrite will run when the program runs, and the GPIO external interrupt callback function is defined in the routine As follows, the function is also very simple, press different keys to perform different functions.
/**
* @brief 中断服务程序中需要做的事情,在HAL库中所有的外部中断服务函数都会调用此函数
*
* @param GPIO_Pin 中断引脚号
*
* @return void
*/
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
delay_ms(50); //消抖
switch(GPIO_Pin)
{
case GPIO_PIN_13: //控制蜂鸣器状态翻转
if( WK_UP == 1)
BEEP_TogglePin;
break;
case GPIO_PIN_8: //控制LED_B灯状态翻转
if( KEY2 == 0)
LED_B_TogglePin;
break;
case GPIO_PIN_9: //控制LED_G灯状态翻转
if( KEY1 == 0)
LED_G_TogglePin;
break;
case GPIO_PIN_10: //控制LED_R灯状态翻转
if( KEY0 == 0)
LED_R_TogglePin;
break;
default:
break;
}
}
delay_ms()
delay_ms()What is running here is delay_us()that the delay is delay_us()realized through a tick timer. The above delay_init()has set fac_us to 80, and it takes 10-6 seconds for the tick timer to count 80 times (the system clock is 80MHz), which is 1us.
/**
* @brief 延时毫秒(ms)函数
*
* @param nms 需要延时多少毫秒
*
* @return void
*/
void delay_ms(u16 nms)
{
u32 i;
for(i = 0; i < nms; i++) delay_us(1000);
}
/**
* @brief 延时微秒(us)函数
*
* @remark nus:0~190887435(最大值即2^32/fac_us@fac_us=22.5)
*
* @param nus 需要延时多少微秒
*
* @return void
*/
void delay_us(u32 nus)
{
u32 ticks;
u32 told, tnow, tcnt = 0;
u32 reload = SysTick->LOAD; //LOAD的值
ticks = nus * fac_us; //需要的节拍数
told = SysTick->VAL; //刚进入时的计数器值
while(1)
{
tnow = SysTick->VAL;
if(tnow != told)
{
if(tnow < told)tcnt += told - tnow; //这里注意一下SYSTICK是一个递减的计数器就可以了.
else tcnt += reload - tnow + told;
told = tnow;
if(tcnt >= ticks)break; //时间超过/等于要延迟的时间,则退出.
}
}
}
LED BEEP operation function
The control functions of LED and buzzer are macro functions, which use HAL_GPIO_WritePin()and HAL_GPIO_TogglePin()two library functions respectively.
#define LED_R(n) (n?HAL_GPIO_WritePin(GPIOE,GPIO_PIN_7,GPIO_PIN_SET):HAL_GPIO_WritePin(GPIOE,GPIO_PIN_7,GPIO_PIN_RESET))
#define LED_R_TogglePin HAL_GPIO_TogglePin(GPIOE,GPIO_PIN_7)
#define LED_G(n) (n?HAL_GPIO_WritePin(GPIOE,GPIO_PIN_8,GPIO_PIN_SET):HAL_GPIO_WritePin(GPIOE,GPIO_PIN_8,GPIO_PIN_RESET))
#define LED_G_TogglePin HAL_GPIO_TogglePin(GPIOE,GPIO_PIN_8)
#define LED_B(n) (n?HAL_GPIO_WritePin(GPIOE,GPIO_PIN_9,GPIO_PIN_SET):HAL_GPIO_WritePin(GPIOE,GPIO_PIN_9,GPIO_PIN_RESET))
#define LED_B_TogglePin HAL_GPIO_TogglePin(GPIOE,GPIO_PIN_9)
#define BEEP(n) (n?HAL_GPIO_WritePin(GPIOB,GPIO_PIN_2,GPIO_PIN_SET):HAL_GPIO_WritePin(GPIOB,GPIO_PIN_2,GPIO_PIN_RESET))
#define BEEP_TogglePin HAL_GPIO_TogglePin(GPIOB,GPIO_PIN_2)