Arduino Basic Syntax

点亮LED灯 basic01

// 初始化函数
void setup() {
    
  //将LED灯引脚(引脚值为13,被封装为了LED_BUTLIN)设置为输出模式
  pinMode(LED_BUILTIN, OUTPUT);
}

// 循环执行函数
void loop() {
    
  digitalWrite(LED_BUILTIN, HIGH);   // 打开LED灯
  delay(1000);                       // 休眠1000毫秒
  digitalWrite(LED_BUILTIN, LOW);    // 关闭LED灯
  delay(1000);                       // 休眠1000毫秒
}

通信

Communicate up and down

引脚操作

The processor writes data on the pin as an outputoutput
The processor reads data from the pins as inputsinput

时间函数

串行通信

下位机到上位机 basic02

If the lower computer sends data to the upper computer,TXThe pin will blink

/* * 需求: 向 arduino 向PC 发送数据: hello world * 实现: * 1. 设置波特率 * 2. Serial.print()或println()发送数据 * */
void setup() {
    
  Serial.begin(57600);
}

void loop() {
    
  delay(3000);
  Serial.print("hello ");
  Serial.println("world");
}

From the upper computer to the lower computer basic03

If the upper computer sends data to the lower computer,RXThe pin will blink

/* * 需求: From the host computer arduino 发送数据 * 实现: * 1. 设置波特率 * 2. 在 loop 中读数据 * */
void setup() {
    
  Serial.begin(57600);
}

void loop() {
    
  if(Serial.available() > 0){
    
    char num = Serial.read();
    // output to the host computer
    Serial.print("I accept: ");
    Serial.println(num);
  }
}

数字IO操作(已演示）

模拟IO操作 basic04

控制LED灯亮度
PWM：脉冲宽度调制技术,设置占空比为LEDIntermittent power supply,PWM的取值范围是[0,255]
0——low,255——high
假设是PWM = 50,high比例是 50/255 约等于1/5,lowThe ratio is approximately4/5
假设是PWM = 100,high比例是 100/255 约等于2/5,lowThe ratio is approximately3/5
How much brightness is passedSet numbers with255相除,Then calculate the percentage

/* * 需求: 控制LED亮度 * 使用的知识点: PWM + analogWrite * * 1. 封装变量: led 引脚,Different brightness levels * 2. 设置LED操作模式 OUTPUT * 3. loop Set a different time intervalPWM值 * */

int led = 13;
int l1 = 255;
int l2 = 127;// 半亮
int l3 = 0;
void setup() {
    
  // put your setup code here, to run once:
  pinMode(led,OUTPUT);
}

void loop() {
    
  delay(2000);
  analogWrite(led,l1);
  delay(2000);
  analogWrite(led,l2);
  delay(2000);
  analogWrite(led,l3);
}

时间函数 basic05

/* * 演示时间函数: millis()与delay() * 需求: 每休眠 2000 ms, 调用一次 millis() 获取时刻,并打印 * */
void setup() {
    
  // put your setup code here, to run once:
  // Need to print toPC端,The baud rate needs to be set
  Serial.begin(57600);
}

void loop() {
    
  // put your main code here, to run repeatedly:
  delay(2000);
  unsigned long t = millis();
  Serial.print("time = ");
  Serial.println(t);
}