[ ST NUCLEO-U575ZI-Q Review] Key Detection - FreeRTOS

lugl4313820

[ ST NUCLEO-U575ZI-Q Review] Key Detection - FreeRTOS [Copy link]

We have achieved multi-task lighting before, and today we will use key detection to control the flashing of LED lights.

Freertos semaphores are used here for control:

/*
  程序：  Binary Semaphore 是一种信号机制
         一个任务(生产者)发出信号。另外一个任务(消费者)接受信号
  公众号：孤独的二进制

  语法：
  SemaphoreHandle_t xHandler; 创建Handler
  xHandler = xSemaphoreCreateBinary(); 创建一个二进制信号量 返回NULL，或者handler
  xSemaphoreGive(xHandler); 生产者+1
  xSemaphoreTake(xHanlder, timeout); 消费者-1 返回pdPASS, 或者pdFAIL

  二进制信号量可以想成就是一个整数 0 或者 1
  Give就是+1
  Take就是-1

  Take的时候如果这个整数是0的话，就等待一直到timeout
*/

The idea is: one is the periodic task of flashing the light, and the other task is to generate the light switch only after receiving the signal. If the button is not pressed, it will keep the original state. If the detection button is pressed, the light will flash periodically.

The procedure is as follows:

#include <Arduino.h>
#include <STM32FreeRTOS.h>

SemaphoreHandle_t xSemaLED = NULL;//创建信号量Handler
TickType_t timeOut = 1000; //用于获取信号的Timeout 

typedef struct {
  byte pin;
  int delayTime;
} LEDFLASH;

void ledFlash(void *pt){
  LEDFLASH *ptLedFlash = (LEDFLASH *)pt;
  byte pin = ptLedFlash->pin;
  int delayTime = ptLedFlash->delayTime;

  pinMode(pin,OUTPUT);
  while(1){
    //Serial.println("led1 flash");
    digitalWrite(pin,!digitalRead(pin));
    vTaskDelay(delayTime);
    
  }
}
void ledFlash2(void *pt){
  byte pin = PC7;
  int delayTime = 500;
  pinMode(pin,OUTPUT);
  while(1){
    if(xSemaphoreTake(xSemaLED,timeOut) == pdTRUE)
    {
      digitalWrite(pin,!digitalRead(pin));
      vTaskDelay(delayTime);
    }
    
  }
}

void readBtn(void *pt)
{
  byte pin = PC13;
  pinMode(pin, INPUT_PULLDOWN);
  while(1)
  {
    if(digitalRead(pin) == HIGH){
      xSemaphoreGive(xSemaLED);
      vTaskDelay(120);
    }
  }
}
LEDFLASH led1,led2;

void setup() {
  Serial.begin(115200);
  led1.pin = PB7;
  led1.delayTime = 200;
  led2.pin = PC7;
  led2.delayTime = 500;
  TaskHandle_t myTask1,butTask;
  xSemaLED = xSemaphoreCreateBinary(); //创建二进制信号量
  if(xTaskCreate(ledFlash,
                  "FLASH LED",
                  1024,
                  (void *)&led1,
                  6,
                  NULL) == pdPASS)
    Serial.println("led1,flash task Created.");
  
  if (xTaskCreate(ledFlash2,
                  "Flash LED.",
                  1024,
                  NULL,
                  6,
                  NULL) == pdPASS)
    Serial.println("led2 flash task Created.");
  
  if (xTaskCreate(readBtn,
                  "Read Button",
                  1024,
                  NULL,
                  1,
                  &butTask)== pdPASS)
    Serial.println("Create Read Button Semaphore.");
  
  vTaskStartScheduler();
}

void loop() {
  // put your main code here, to run repeatedly:
}

See the video for experimental phenomena.

2022-12-14 09.41拍摄的影片

okhxyyo

Review summary: Free application | ST NUCLEO-U575ZI-Q https://en.eeworld.com/bbs/thread-1228653-1-1.html