ESP8266连接服务器后立即断开，无法向网站传输数据求助

Hey there! Let’s troubleshoot this ESP8266 connection issue step by step— I’ve run into similar headaches with 000webhost before, so here’s what to check:

1. First, Confirm Your WiFi Connection is Solid #

Before worrying about the server, make sure the ESP8266 is actually connected to your WiFi network. Send these AT commands (via your serial monitor or code) and verify the responses:

• AT+CWJAP="YOUR_SSID","YOUR_WIFI_PASSWORD"
• You should see WIFI CONNECTED followed by WIFI GOT IP. If not, double-check your SSID/password, or try moving the ESP8266 closer to your router for better signal.

2. Fix Your AT Command Sequence & Domain Handling #

000webhost’s servers can be picky about how you initiate connections. Here’s the correct flow for a single TCP connection:

• First set single-connection mode: AT+CIPMUX=0
• Then initiate the TCP connection with your actual domain (not IP— 000webhost uses dynamic IPs):

  AT+CIPSTART="TCP","your-000webhost-domain.com",80
  

• If the connection drops immediately, test DNS resolution first with AT+CIPDOMAIN="your-domain.com". If it fails, manually set Google’s DNS on the ESP8266:

  AT+CWDNSSET=1,"8.8.8.8","8.8.4.4"
  

3. Follow 000webhost’s HTTP Request Rules #

Free 000webhost accounts block malformed HTTP requests, which is a common reason connections get closed instantly. When sending data, your request must follow strict HTTP standards:

• Include a proper Host header matching your domain
• End the request with two newline characters (\r\n\r\n)
• Example valid request (replace with your script path):

  GET /submit-data.php?sensor=123 HTTP/1.1
  Host: your-domain.com
  Connection: close
  
  

4. Fix SoftwareSerial Instability #

Your code uses SoftwareSerial for ESP8266 communication— this can be flaky at high baud rates like 115200. Try these fixes:

• First, lower the ESP8266’s AT command baud rate permanently:

  AT+UART_DEF=9600,8,1,0,0
  

  Then restart the ESP8266, and update your code to use 9600 for SoftwareSerial:

  mySerial.begin(9600);
  

• Also, make sure your Arduino’s serial monitor is set to the same baud rate as SoftwareSerial— mismatched rates cause garbage data, which breaks AT commands.

5. Test the Server Separately #

Rule out 000webhost-side issues by testing the server from your computer:

• Use curl in your terminal:

  curl http://your-domain.com/submit-data.php?test=1
  

• If this fails, log into your 000webhost dashboard to check if your site is active, hasn’t hit bandwidth limits, or if your PHP script has errors.

Optimized Code Snippet #

Here’s a cleaned-up version of your code that follows the above rules:

#include <SoftwareSerial.h>
SoftwareSerial mySerial(2, 3); // RX, TX

const char* wifiSSID = "YOUR_WIFI_NAME";
const char* wifiPass = "YOUR_WIFI_PASSWORD";
const char* serverDomain = "your-000webhost-domain.com";
const int serverPort = 80;
int LEDPIN = 13;

void setup() {
  Serial.begin(9600);
  mySerial.begin(9600);
  pinMode(LEDPIN, OUTPUT);
  digitalWrite(LEDPIN, LOW);

  // Connect to WiFi
  mySerial.println("AT+CWJAP=\"" + String(wifiSSID) + "\",\"" + String(wifiPass) + "\"");
  delay(5000);
  
  if (mySerial.find("WIFI GOT IP")) {
    Serial.println("WiFi connected successfully!");
    digitalWrite(LEDPIN, HIGH);
  } else {
    Serial.println("WiFi connection failed. Check SSID/password.");
    while(1); // Halt if no WiFi
  }
}

void loop() {
  // Initiate TCP connection
  mySerial.println("AT+CIPSTART=\"TCP\",\"" + String(serverDomain) + "\"," + String(serverPort));
  delay(2000);

  if (mySerial.find("CONNECT")) {
    Serial.println("Connected to server! Sending data...");
    
    // Build valid HTTP request (replace with your data/script path)
    String httpRequest = "GET /submit-data.php?sensor_value=42 HTTP/1.1\r\n";
    httpRequest += "Host: " + String(serverDomain) + "\r\n";
    httpRequest += "Connection: close\r\n\r\n";

    // Send data length then the request
    mySerial.println("AT+CIPSEND=" + String(httpRequest.length()));
    delay(1000);
    
    if (mySerial.find(">")) {
      mySerial.print(httpRequest);
      Serial.println("Data sent! Waiting for response...");
      delay(3000); // Give server time to respond
    }

    // Close the connection
    mySerial.println("AT+CIPCLOSE");
  } else {
    Serial.println("Failed to connect to server. Retrying in 10s...");
  }

  delay(10000); // Send data every 10 seconds
}

Start with the simplest checks first (WiFi connection, baud rate matching) and work your way up— that’s usually the fastest way to fix these issues!

内容的提问来源于stack exchange，提问作者Salihi Abdullahi