Hello everybody! I use WiFiClient to connect to my server by socket, but I cannot connect to the server, it seems that function WiFiClient::connected() return 0, I don't know the correct approach to connect a server by socket, which class should I use, WiFiClient or HTTPClient or other class I don't know?
Usecase: I use it to upload a String to my server to verify the user identity first, after getting the returning message from the server I would send a byte array to the server.
Here is my key code:
#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>
WiFiClient photoClient;
int uploadPhoto(){
byte tryTime=0;
String returnMsg="";
String MACAddr=WiFi.macAddress();
MACAddr.replace(":","");
writeSerial(("ACCESS:"+WEBSITE_SEND_PHOTO).c_str());
photoClient.setNoDelay(true);
photoClient.connect(WEBSITE_SEND_PHOTO,3000);
while(!photoClient.connected()){//wait for connection success
writeRawSerial(F("."),false);
if((tryTime++)>=10){//try 10 times
tryTime=0;
writeRawSerial(F(" "),true);//writeRawSerial() and writeSerial() is defined
writeSerial(F("<STATUS>FIRST_CONNECTION_FAIL</STATUS>"));
writeSerial("<INFO>"+(String(photoClient.connected()))+"</INFO>");
return -1;
}
delay(1000);
}
photoClient.write((String("<TYPE>gas</TYPE><USER_ID>"+USER_ID+"</USER_ID><MAC>"+MACAddr+"</MAC><END>")).c_str());//send verification info
writeSerial(F("photoClient.write((String(\"<TYPE>gas</TYPE><USER_ID>\"+USER_ID+\"</USER_ID><MAC>\"+MACAddr+\"</MAC><END>\")).c_str());"));
while(!photoClient.available()){//wait for returning message
writeRawSerial(F("."),false);
if((tryTime++)>=10){
tryTime=0;
writeRawSerial(F(" "),true);
writeSerial(F("<STATUS>FIRST_SEND_FAIL</STATUS>"));
return -1;
}
delay(200);
}
writeRawSerial(F(" "),true);
while(photoClient.available()){
returnMsg+=(char)photoClient.read();
}
bool returnStatus=processReturnMsg(returnMsg);
writeHttpReturnSerial(returnMsg);
if(returnStatus){//send array
returnMsg="";
writeSerial(F("<STATUS>START_SENDING</STATUS>"));
photoClient.write(Img,imgSize);
while(!photoClient.available()){
writeRawSerial(F("."),false);
if((tryTime++)>=10){
tryTime=0;
writeRawSerial(F(" "),true);
writeSerial(F("<STATUS>SECOND_SEND_FAIL</STATUS>"));
return -1;
}
delay(200);
}
writeRawSerial(F(" "),true);
while(photoClient.available()){
returnMsg+=(char)photoClient.read();
}
photoClient.stop();
returnStatus=processReturnMsg(returnMsg);
if(returnStatus){//succeed
delete(Img);
writeSerial(F("<STATUS>SEND_SUCCESS</STATUS>"));
return 1;
}
else{//failed
writeSerial(F("<STATUS>SEND_FAIL</STATUS>"));
return 0;
}
}
else{//verification error
photoClient.stop();
writeSerial(F("<STATUS>NONE_USER</STATUS>"));
return 0;
}
}
Thank you for reading my question!
Juraj
March 17, 2018, 6:41pm
2
port is 3000. is it enabled on firewall of the server?
Juraj:
I tested it with Java client and Android client I wrote, it can be accessed. So there will be no problem with the server.
Juraj:
I tried WiFiClient like what I posted and also HTTPClient, I just cannot access to the server with this port, both failed when using function connected() to judge connection status.
Juraj:
I don't know what's the limitation of the protocol that WiFiClient and HTTPClient support.
Juraj
March 18, 2018, 8:26am
6
WiFiClient is socket: connect, write, flush, read, close. HTTPClient handles HTTP protocol over WiFiClient: get, post, parse response
Juraj:
That's confusing...
Juraj
March 18, 2018, 1:05pm
8
what is the value of WEBSITE_SEND_PHOTO?
Juraj:
I translated my code to php just now, but the test client is still run on java.
Here is server code in php.
<?php
set_time_limit ( 0 );
$ip = '172.18.89.152';
$port = 3000;
if (($sock = socket_create ( AF_INET, SOCK_STREAM, SOL_TCP )) < 0)
{
echo "socket_create() failed: reason: " . socket_strerror ( $sock ) . "\n";
}
if (($ret = socket_bind ( $sock, $ip, $port )) < 0)
{
echo "socket_bind() failed: reason: " . socket_strerror ( $ret ) . "\n";
}
if (($ret = socket_listen ( $sock, 4 )) < 0)
{
echo "socket_listen() failed: reason: " . socket_strerror ( $ret ) . "\n";
}
do
{
if (($msgsock = socket_accept ( $sock )) < 0)
{
echo "socket_accept() failed: reason: " . socket_strerror ( $msgsock ) . "\n";
break;
}
else
{
$buf = socket_read ( $msgsock, 8192 );
$return_msg='<STATUS>success</STATUS><DELAY>10</DELAY>[END]';
socket_write ( $msgsock, $return_msg, strlen ( $return_msg ) );
$talkback = "Recieve buffer: $buf\n";
echo $talkback;
}
socket_close ( $msgsock );
} while ( true );
socket_close ( $sock );
?>
And here is the test client.
package socket_test;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
public class Client {
public static void main(String[] args) {
try {
Socket socket = new Socket("172.18.89.152", 3000);
Thread thread=new Thread(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
try {
PrintWriter out=new PrintWriter(socket.getOutputStream());
try {
out.println("New msg");
} catch (Exception e) {
e.printStackTrace();
};
out.flush();
InputStream inputStream = socket.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader br = new BufferedReader(inputStreamReader);
String msg;
try {
while ((msg=br.readLine())!=null) {
System.out.println(msg);
}
} catch (Exception e) {
e.printStackTrace();
}
br.close();
inputStreamReader.close();
inputStream.close();
out.close();
socket.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
});
thread.start();
}catch(Exception e){
e.printStackTrace();
System.out.println("Server is offline");
}
}
}
Juraj
March 18, 2018, 3:07pm
10
and in your Arduino sketch you connect to a WiFi network in setup()? show the complete sketch
Juraj
March 18, 2018, 6:28pm
12
ok, but the sketch doesn't answer the question if the esp is connected to WiFi network. it is some PC program sending commands to esp over Serial?
Juraj:
As I said, the android app sends wifi info to the arduino through HC05, then the arduino sends wifi info the ESP8266, then ESP8266 connects to the target wifi.
Juraj
March 18, 2018, 6:33pm
14
write a simple sketch to test the connection
Juraj:
I found that it had connected to a wifi after testing, and the HTTPClient did work while sending a HTTP request to my server, but the socket connection didn't work.
I had the same problem on same setup. HTTPClient works but WifiClient does not.
