Arduino返回錯誤的整數值

Question

我有一些代碼，根據網站上的值（包含一個數字的空白頁開啓/關閉LED，頁面上的數字表示LED應該閃爍的次數）

的問題是，循環繼續運行。
我可以通過手動設置整數值（int c = 3）解決問題。

不知道我的問題是什麼。
的，你是一個可以點我正確的方向

Ur L：http://b2b.as/lan.php?pid=8855

代碼：

#include <Ethernet.h> 
#include <SPI.h> 

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; 
byte ip[] = { 192, 168, 1, 104 }; 
char server[] = "b2b.as"; 

void setup() 
{ 
    Ethernet.begin(mac, ip); 
    Serial.begin(9600); 

    delay(1000); 

    Serial.println(Ethernet.localIP()); 
    Serial.println(); 

    // Set digital pin as output 
    // 5V 
    pinMode(8, OUTPUT); 
} 

void loop() 
{ 

    // 
    Serial.print("\n-----\n"); 

    // Connect to the server 
    Serial.print("connecting to URL ..."); 

    // Start LAN connection 
    EthernetClient client; 
    if (client.connect(server, 80)) { 
    Serial.println("connected"); 
    client.println("GET /lan.php?pid=8855"); 
    client.println(); 
    } else { 
    Serial.println("connection failed"); 
    } 

    // Wait a moment for data to arrive 
    // Note: This is NOT a reliable way of doing this! 
    delay(1000); 

    if (client.available() > 0) { 

    char c = atoi(client.read()); 

    Serial.print("page value (pick): "); 
    Serial.print(c, DEC); 
    Serial.print("\n"); 

    for (int x = 1; x <= int(c); x++) { 
     Serial.print("picking: #"); 
     Serial.println(x); 
     digitalWrite(8, HIGH); 
     Serial.println("8 HIGH ..."); 
     delay(5000); // Add switch 
     digitalWrite(8, LOW); 
     Serial.println("8 LOW ..."); 
     delay(1000); 
    } 

    Serial.print("end"); 

    } 

    // Disconnect the client 
    if (client.connected()) { 
    //Serial.println(); 
    Serial.print("disconnecting"); 
    client.stop(); 
    } 

    // Wait another 9s, which will give us a delay of roughly 10s 
    delay(9000); 
} 

Answer 1

我假設調用lan.php?pid=8855將只返回值沒有任何格式，例如HTML，XML，JSON。然後你的代碼基本上將ASCII字符3轉換爲一個整數，它給你的整數值33（見ASCII Table）。因此，你的循環不會停止。

解決方案

只需使用atoi函數將其轉換爲整數。

char c = atoi(client.read()); 

Answer 2

看來，toInt（）是我正在尋找的功能。它將字符串轉換爲整數並修復循環。

https://www.arduino.cc/en/Reference/StringToInt

碼已更新，它似乎工作：

#include <Ethernet.h> 
#include <SPI.h> 

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; 
byte ip[] = { 192, 168, 1, 104 }; 
char server[] = "b2b.as"; 

void setup() 
{ 
    Ethernet.begin(mac, ip); 
    Serial.begin(9600); 

    delay(1000); 

    Serial.println(Ethernet.localIP()); 
    Serial.println(); 

    // Set digital pin as output 
    // 5V 
    pinMode(8, OUTPUT); 
} 

void loop() 
{ 

    // 
    Serial.print("\n-----\n"); 

    // Connect to the server 
    Serial.print("connecting to URL ..."); 

    // Start LAN connection 
    EthernetClient client; 
    if (client.connect(server, 80)) { 
    Serial.println("connected"); 
    client.println("GET /lan.php?pid=8855"); 
    client.println(); 
    } else { 
    Serial.println("connection failed"); 
    } 

    // Wait a moment for data to arrive 
    // Note: This is NOT a reliable way of doing this! 
    delay(1000); 

    if (client.available() > 0) { 

    String pickNum; 

    while (client.available()) { 
     char c = client.read(); // gets one byte from serial buffer 
     pickNum += c; // count 
     delay(2); // delay for buffer 
    } 

    Serial.print("page value (pick): "); 
    Serial.println(pickNum); 

    for (int x = 1; x <= pickNum.toInt(); x++) { 
     Serial.print("picking: #"); 
     Serial.println(x); 
     digitalWrite(8, HIGH); 
     Serial.println("8 HIGH ..."); 
     delay(1000); // Add switch 
     digitalWrite(8, LOW); 
     Serial.println("8 LOW ..."); 
     delay(1000); 
    } 

    Serial.print("end"); 

    } 

    // Disconnect the client 
    if (client.connected()) { 
    //Serial.println(); 
    Serial.print("disconnecting"); 
    client.stop(); 
    } 

    // Wait another 9s, which will give us a delay of roughly 10s 
    delay(9000); 
}