c - Arduino 以太网网络服务器问题

Question

我的 Arduino 代码遇到了一些问题，我制作了一个 Arduino 以太网 SD Web 服务器，它的任务是获取命令并点亮电源开关并显示开关是打开还是关闭，一切都很完美。但问题是我可以连接到 arduino Web 服务器几次，然后发生了一些事情，我无法连接到它，然后我必须重新启动它才能再次连接到它。有人可以帮助我吗？

#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
#include <RemoteTransmitter.h>
// size of buffer used to capture HTTP requests
#define REQ_BUF_SZ   60

// MAC address from Ethernet shield sticker under board
byte mac[] = { 0x90, 0xA2, 0xDA, 0x0E, 0x95, 0x2F };
IPAddress ip(192, 168, 1, 200); // IP address, may need to change depending on network
EthernetServer server(80);  // create a server at port 80
File webFile;               // the web page file on the SD card
char HTTP_req[REQ_BUF_SZ] = {0}; // buffered HTTP request stored as null terminated string
char req_index = 0;              // index into HTTP_req buffer
boolean LED_state[3] = {0}; // stores the states of the LEDs
ActionTransmitter actionTransmitter(9);

void setup()
{
  // Everything resets to Off if arduino is reseted
  actionTransmitter.sendSignal(1,'A',false);
  actionTransmitter.sendSignal(1,'B',false);
  actionTransmitter.sendSignal(1,'C',false);

    // disable Ethernet chip
    pinMode(10, OUTPUT);
    digitalWrite(10, HIGH);

    Serial.begin(9600);       // for debugging

    // initialize SD card
    Serial.println("Initializing SD card...");
    if (!SD.begin(4)) {
        Serial.println("ERROR - SD card initialization failed!");
        return;    // init failed
    }
    Serial.println("SUCCESS - SD card initialized.");
    // check for index.htm file
    if (!SD.exists("index.htm")) {
        Serial.println("ERROR - Can't find index.htm file!");
        return;  // can't find index file
    }
    Serial.println("SUCCESS - Found index.htm file.");


    Ethernet.begin(mac, ip);  // initialize Ethernet device
    server.begin();           // start to listen for clients
}

void loop()
{
    EthernetClient client = server.available();  // try to get client

    if (client) {  // got client?
        boolean currentLineIsBlank = true;
        while (client.connected()) {
            if (client.available()) {   // client data available to read
                char c = client.read(); // read 1 byte (character) from client
                // limit the size of the stored received HTTP request
                // buffer first part of HTTP request in HTTP_req array (string)
                // leave last element in array as 0 to null terminate string (REQ_BUF_SZ - 1)
                if (req_index < (REQ_BUF_SZ - 1)) {
                    HTTP_req[req_index] = c;          // save HTTP request character
                    req_index++;
                }
                // last line of client request is blank and ends with \n
                // respond to client only after last line received
                if (c == '\n' && currentLineIsBlank) {
                    // send a standard http response header
                    client.println("HTTP/1.1 200 OK");
                    // remainder of header follows below, depending on if
                    // web page or XML page is requested
                    // Ajax request - send XML file
                    if (StrContains(HTTP_req, "ajax_inputs")) {
                        // send rest of HTTP header
                        client.println("Content-Type: text/xml");
                        client.println("Connection: keep-alive");
                        client.println();
                        SetLEDs();
                        // send XML file containing input states
                        XML_response(client);
                    }
                    else {  // web page request
                        // send rest of HTTP header
                        client.println("Content-Type: text/html");
                        client.println("Connection: keep-alive");
                        client.println();
                        // send web page
                        webFile = SD.open("index.htm");        // open web page file
                        if (webFile) {
                            while(webFile.available()) {
                                client.write(webFile.read()); // send web page to client
                            }
                            webFile.close();
                        }
                    }
                    // display received HTTP request on serial port
                    Serial.print(HTTP_req);
                    // reset buffer index and all buffer elements to 0
                    req_index = 0;
                    StrClear(HTTP_req, REQ_BUF_SZ);
                    break;
                }
                // every line of text received from the client ends with \r\n
                if (c == '\n') {
                    // last character on line of received text
                    // starting new line with next character read
                    currentLineIsBlank = true;
                } 
                else if (c != '\r') {
                    // a text character was received from client
                    currentLineIsBlank = false;
                }
            } // end if (client.available())
        } // end while (client.connected())
        delay(1);      // give the web browser time to receive the data
        client.stop(); // close the connection
    } // end if (client)
}

// checks if received HTTP request is switching on/off LEDs
// also saves the state of the LEDs
void SetLEDs(void)
{

    // LED 3 (pin 8)
    if (StrContains(HTTP_req, "LED1=1")) {
        LED_state[0] = 1;  // save LED state
        actionTransmitter.sendSignal(1,'A',true);
        Serial.print("button 1 on ");
    }
    else if (StrContains(HTTP_req, "LED1=0")) {
        LED_state[0] = 0;  // save LED state
        actionTransmitter.sendSignal(1,'A',false);
        Serial.print("button 1 off");
    }
    // LED 4 (pin 9)
    if (StrContains(HTTP_req, "LED2=1")) {
        LED_state[1] = 1;  // save LED state
        actionTransmitter.sendSignal(1,'B',true);
    }
    else if (StrContains(HTTP_req, "LED2=0")) {
        LED_state[1] = 0;  // save LED state
        actionTransmitter.sendSignal(1,'B',false);
    }
     if (StrContains(HTTP_req, "LED3=1")) {
        LED_state[2] = 1;  // save LED state
        actionTransmitter.sendSignal(1,'C',true);
    }
    else if (StrContains(HTTP_req, "LED3=0")) {
        LED_state[2] = 0;  // save LED state
        actionTransmitter.sendSignal(1,'C',false);
    }
}

// send the XML file with analog values, switch status
//  and LED status
void XML_response(EthernetClient cl)
{
    int analog_val;            // stores value read from analog inputs
    int count;                 // used by 'for' loops


    cl.print("<?xml version = \"1.0\" ?>");
    cl.print("<inputs>");


    // button LED states
    // LED3
    cl.print("<LED>");
    if (LED_state[0]) {
        cl.print("on");

    }
    else {
        cl.print("off");

    }
    cl.println("</LED>");
    // LED4
    cl.print("<LED>");
    if (LED_state[1]) {
        cl.print("on");
    }
    else {
        cl.print("off");
    }
    cl.println("</LED>");

    // new led
    cl.print("<LED>");
    if (LED_state[2]) {
        cl.print("on");

    }
    else {
        cl.print("off");

    }
    cl.println("</LED>");

    cl.print("</inputs>");
}


// sets every element of str to 0 (clears array)
void StrClear(char *str, char length)
{
    for (int i = 0; i < length; i++) 
    {
        str[i] = 0;
    }
}

// searches for the string sfind in the string str
// returns 1 if string found
// returns 0 if string not found
char StrContains(char *str, char *sfind)
{
    char found = 0;
    char index = 0;
    char len;

    len = strlen(str);

    if (strlen(sfind) > len) {
        return 0;
    }
    while (index < len) {
        if (str[index] == sfind[found]) {
            found++;
            if (strlen(sfind) == found) {
                return 1;
            }
        }
        else {
            found = 0;
        }
        index++;
    }

    return 0;
}

Answer 1

根据您的问题描述...您可能会耗尽内存。当然，这只是一种可能。尝试使用 FreeMemory 库来监控内存利用率。如果每次发送命令时内存量都会下降，那么您就有了答案。

请注意，Arduino 草图在耗尽最后一 block 内存时(通常情况下)就会失败。堆栈覆盖了一些数据区域，草图在某种程度上变得疯狂。

当然，您需要使用串行监视器运行草图来查看 FreeMemory 输出。放入一些 Serial.print 语句也可能有助于确定草图的确切悬挂位置

顺便说一句，好主意。