Arduino逻辑教程：如果，for，while和switch case语句

Arduino编程用途 控制结构 例如 如果是，while和switch case 在草图中控制决策和循环。这些结构允许 Arduino 响应条件，重复任务并根据输入执行不同的代码块。

1。if语句（有条件执行）

这 如果语句 用于执行代码块 只有满足指定条件.

句法

if (condition) {
   // Code to execute if condition is true
}

示例：根据按钮按下按钮打开LED

const int buttonPin = 2;  // Button connected to pin 2
const int ledPin = 13;    // LED connected to pin 13

void setup() {
    pinMode(buttonPin, INPUT);
    pinMode(ledPin, OUTPUT);
}

void loop() {
    int buttonState = digitalRead(buttonPin);  // Read button state

    if (buttonState == HIGH) {
        digitalWrite(ledPin, HIGH); // Turn LED on if button is pressed
    } else {
        digitalWrite(ledPin, LOW);  // Turn LED off otherwise
    }
}

if-else语句

if (temperature > 30) {
    Serial.println("It's too hot!");
} else {
    Serial.println("Temperature is normal.");
}

如果else if语句

if (temperature > 30) {
    Serial.println("It's too hot!");
} else if (temperature < 10) {
    Serial.println("It's too cold!");
} else {
    Serial.println("Temperature is comfortable.");
}

2。对于循环（重复任务固定数量）

一个 用于循环 运行一个代码 固定数量。通常用于 迭代阵列或控制重复任务.

句法

for (initialization; condition; increment) {
   // Code to execute in each iteration
}

示例：闪烁LED 5次

const int ledPin = 13;

void setup() {
    pinMode(ledPin, OUTPUT);
}

void loop() {
    for (int i = 0; i < 5; i++) { // Loop runs 5 times
        digitalWrite(ledPin, HIGH);  // Turn LED on
        delay(500);  // Wait 500 ms
        digitalWrite(ledPin, LOW);   // Turn LED off
        delay(500);
    }
    delay(2000); // Pause before repeating
}

示例：通过数组运行

int numbers[] = {1, 2, 3, 4, 5};

void setup() {
    Serial.begin(9600);
}

void loop() {
    for (int i = 0; i < 5; i++) {
        Serial.println(numbers[i]);  // Print each number in the array
    }
    delay(2000);
}

3。循环（重复直到满足条件）

一个循环运行一个代码 只要指定条件保持真实.

句法

while (condition) {
   // Code to execute while the condition is true
}

示例：等待按钮按

const int buttonPin = 2;

void setup() {
    pinMode(buttonPin, INPUT);
    Serial.begin(9600);
}

void loop() {
    Serial.println("Waiting for button press...");
    
    while (digitalRead(buttonPin) == LOW) {
        // Stay in loop until button is pressed
    }
    
    Serial.println("Button pressed!");
}

示例：倒数计时器

int count = 10;

void setup() {
    Serial.begin(9600);
}

void loop() {
    while (count > 0) {
        Serial.print("Countdown: ");
        Serial.println(count);
        count--;
        delay(1000);
    }
    Serial.println("Liftoff!");
    delay(5000); // Restart countdown after delay
    count = 10;  // Reset count
}

4。开关情况（有效处理多个条件）

一个 开关案例语句 在何时使用 需要检查多个条件，使其成为替代 如果else if-else 链。

句法

switch (variable) {
    case value1:
        // Code to execute if variable == value1
        break;
    case value2:
        // Code to execute if variable == value2
        break;
    default:
        // Code to execute if none of the cases match
}

示例：用旋转开关控制LED

const int ledPin = 13;
int mode = 1;  // Example mode variable

void setup() {
    pinMode(ledPin, OUTPUT);
    Serial.begin(9600);
}

void loop() {
    switch (mode) {
        case 1:
            Serial.println("Mode 1: LED ON");
            digitalWrite(ledPin, HIGH);
            break;
        case 2:
            Serial.println("Mode 2: LED BLINKING");
            digitalWrite(ledPin, HIGH);
            delay(500);
            digitalWrite(ledPin, LOW);
            delay(500);
            break;
        case 3:
            Serial.println("Mode 3: LED OFF");
            digitalWrite(ledPin, LOW);
            break;
        default:
            Serial.println("Invalid Mode");
            break;
    }
}

示例：使用按钮通过模式循环

const int buttonPin = 2;
int mode = 1;

void setup() {
    pinMode(buttonPin, INPUT);
    Serial.begin(9600);
}

void loop() {
    if (digitalRead(buttonPin) == HIGH) {
        mode++;
        if (mode > 3) mode = 1;  // Reset mode to 1 if it exceeds 3
        delay(500);  // Debounce delay
    }

    switch (mode) {
        case 1:
            Serial.println("Mode 1: Low Power Mode");
            break;
        case 2:
            Serial.println("Mode 2: Normal Mode");
            break;
        case 3:
            Serial.println("Mode 3: High Performance Mode");
            break;
        default:
            Serial.println("Invalid Mode");
            break;
    }
}