FreeRTOS之消息队列
声明:本人按照正点原子的FreeRTOS例程进行学习的,欢迎各位大佬指责和批评,谢谢!
消息队列的定义
- 消息队列其实是两个任务之间的数据传递的过程,在没有操作系统之前,使用的是全局变量;使用了FreeRTOS操作系统,就要使用“队列”的机制来完成任务与任务之间、任务与中断之间的数据传递。
- 下面是实验举例:Task1任务获取到键值,使用消息队列发送函数;KeyProcess任务中接收到消息队列,使用消息队列接收函数:
- 创建消息队列
#define KEYMSG_Q_NUM 1
#define MESSAGE_Q_NUM 4
QueueHandle_t Key_Queue;
QueueHandle_t Message_Queue;
void start_task(void *pvParameters)
{
taskENTER_CRITICAL();
Key_Queue=xQueueCreate(KEYMSG_Q_NUM,sizeof(u8));
Message_Queue=xQueueCreate(MESSAGE_Q_NUM,USART_REC_LEN);
xTaskCreate((TaskFunction_t )task1_task, my_mem_init(SRAMIN) 此函数在#include"malloc.h"
(const char* )"task1_task", 队列中需要申请内存
(uint16_t )TASK1_STK_SIZE,
(void* )NULL,
(UBaseType_t )TASK1_TASK_PRIO,
(TaskHandle_t* )&Task1Task_Handler);
xTaskCreate((TaskFunction_t )Keyprocess_task,
(const char* )"keyprocess_task",
(uint16_t )KEYPROCESS_STK_SIZE,
(void* )NULL,
(UBaseType_t )KEYPROCESS_TASK_PRIO,
(TaskHandle_t* )&Keyprocess_Handler);
vTaskDelete(StartTask_Handler);
taskEXIT_CRITICAL();
}
- 发送消息----队列
void task1_task(void *pvParameters)
{
u8 key,i;
BaseType_t err;
while(1)
{
key = KEY_Scan(0);
if((Key_Queue != NULL)&&(key))
{
err=xQueueSend(Key_Queue,&key,10);
if(err==errQUEUE_FULL)
{
printf("队列Key_Queue已满,数据发送失败!\r\n");
}
}
i++;
if(i==100)
{
i=0;
LED1=!LED1;
}
vTaskDelay(10);
}
}
- 接收消息----队列
void keyprocess_task(void *pvParameters)
{
u8 key;
while(1)
{
if(Key_Queue != NULL)
{
if(xQueueReceive(Key_Queue,&key,portMAX_DELAY))
{
switch(key)
{
case WKUP_PRES:LED0=!LED0;break;
case KEY2_PRES:BEEP=!BEEP;break;
case KEY0_PRES:printf("已经接收到\r\n");break;
}
}
}
vTaskDelay(10);
}
}
- 下面是主函数
#include "sys.h"
#include "delay.h"
#include "usart.h"
#include "led.h"
#include "timer.h"
#include "lcd.h"
#include "FreeRTOS.h"
#include "task.h"
#include "key.h"
#include "beep.h"
#include "queue.h"
#include "malloc.h"
#define START_TASK_PRIO 1
#define START_STK_SIZE 256
TaskHandle_t StartTask_Handler;
void start_task(void *pvParameters);
#define LED_TASK_PRIO 2
#define LED_STK_SIZE 128
TaskHandle_t LedTask_Handler;
void led_task(void *pvParameters);
#define TASK1_TASK_PRIO 3
#define TASK1_STK_SIZE 256
TaskHandle_t Task1Task_Handler;
void task1_task(void *pvParameters);
#define TASK2_TASK_PRIO 4
#define TASK2_STK_SIZE 128
TaskHandle_t Task2Task_Handler;
void task2_task(void *pvParameters);
void LowerToCap(u8 *str,u8 len)
{
u8 i;
for(i=0;i<len;i++)
{
if((96<str[i]) && (str[i]<123))
{
str[i] = str[i] - 32;
}
}
}
void disp_str(u8* str)
{
LCD_Fill(5,230,110,245,WHITE);
LCD_ShowString(5,230,100,16,16,str);
}
#define KEYMSG_Q_NUM 1
#define MESSAGE_Q_NUM 4
QueueHandle_t Key_Queue;
QueueHandle_t Message_Queue;
u8 test;
int lcd_discolor[14]={ WHITE, BLACK, BLUE, BRED,
GRED, GBLUE, RED, MAGENTA,
GREEN, CYAN, YELLOW,BROWN,
BRRED, GRAY };
char InfoBuffer[1000];
int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
delay_init(168);
uart_init(115200);
LED_Init();
KEY_Init();
BEEP_Init();
LCD_Init();
my_mem_init(SRAMIN);
POINT_COLOR = RED;
LCD_ShowString(30,10,200,16,16,"ATK STM32F407");
LCD_ShowString(30,30,200,16,16,"FreeRTOS 测试");
LCD_ShowString(30,50,200,16,16,"任务状态查询");
xTaskCreate((TaskFunction_t )start_task,
(const char* )"start_task",
(uint16_t )START_STK_SIZE,
(void* )NULL,
(UBaseType_t )START_TASK_PRIO,
(TaskHandle_t* )&StartTask_Handler);
vTaskStartScheduler();
}
void start_task(void *pvParameters)
{
taskENTER_CRITICAL();
Key_Queue=xQueueCreate(KEYMSG_Q_NUM,sizeof(u8));
Message_Queue=xQueueCreate(MESSAGE_Q_NUM,USART_REC_LEN);
xTaskCreate((TaskFunction_t )led_task,
(const char* )"keyprocess_task",
(uint16_t )LED_STK_SIZE,
(void* )NULL,
(UBaseType_t )LED_TASK_PRIO,
(TaskHandle_t* )&LedTask_Handler);
xTaskCreate((TaskFunction_t )task1_task,
(const char* )"task1_task",
(uint16_t )TASK1_STK_SIZE,
(void* )NULL,
(UBaseType_t )TASK1_TASK_PRIO,
(TaskHandle_t* )&Task1Task_Handler);
xTaskCreate((TaskFunction_t )task2_task,
(const char* )"task2_task",
(uint16_t )TASK2_STK_SIZE,
(void* )NULL,
(UBaseType_t )TASK2_TASK_PRIO,
(TaskHandle_t* )&Task2Task_Handler);
vTaskDelete(StartTask_Handler);
taskEXIT_CRITICAL();
}
void task1_task(void *pvParameters)
{
u8 key,i;
BaseType_t err;
while(1)
{
key = KEY_Scan(1);
if((Key_Queue != NULL)&&(key))
{
vTaskDelay(100);
if(key == KEY0_PRES)
{
test ++;
}
err=xQueueSend(Key_Queue,&test,10);
if(err==errQUEUE_FULL)
{
printf("队列Key_Queue已满,数据发送失败!\r\n");
}
}
i++;
if(i==100)
{
i=0;
LED1=!LED1;
}
vTaskDelay(10);
}
}
void led_task(void *pvParameters)
{
while(1)
{
if(Key_Queue != NULL)
{
if(xQueueReceive(Key_Queue,&test,portMAX_DELAY))
{
printf("key0 : %d\r\n",test);
}
}
vTaskDelay(10);
}
}
void task2_task(void *pvParameters)
{
u8 i;
while(1)
{
i++;
if(i==100)
{
i=0;
LED0=!LED0;
}
vTaskDelay(10);
}
}
结束
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