Hello everyone,
I am trying to make a simple connection between my Arduino and a local server(using express in nodejs) running on my laptop and both are connected directly, without a router or switch. However it always fails.
I catched the return value from ''client.connect(server, 8080)'' It is always "connection failed".
I've tried a different EthernetSield and cable.
Thanks so much to everyone!
My code:
#include <SPI.h>
#include <Ethernet.h>
// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(169,254,188,3); //local ip
IPAddress server(169,254,191,189); //ip where server is running
EthernetClient client;
void setup() {
Serial.begin(9600);
Serial.println("Starting...");
Ethernet.begin(mac,ip);
if (client.connect(server, 8080)) {
Serial.println("connected");
} else {
Serial.println("connection failed");
}
Serial.println(Ethernet.localIP());
}
void loop() {
if (client.available()) {
char c = client.read();
Serial.print(c);
}
}
can you ping the Ethernet board from the PC?
make sure your static IP addresses are on the same subnet
I connected an EthernetSheildV1 direct to a Windows 10 PC setting the Win10 Ethernet static IP to 192.168.1.115
ran following program on Arduino Uno with EthernetSheildV1
// TCPcharClient.ino - a simple TCP chat program
// not using DHCP so check subnet address range is correct
#include <Ethernet.h>
#include <SPI.h>
byte mac[] = { 0x90, 0xA2, 0xDA, 0x0E, 0xD0, 0x93 };
// Set the static IP address to use if the DHCP fails to assign
IPAddress ip(192, 168, 1,115);
IPAddress myDns(192, 168, 1,254); // DNS server
// Initialize the Ethernet client library
EthernetClient client;
byte server[] = { 192, 168, 1, 10 }; // server IP address
int serverPort=10000; // server TCP port (open any firewall on server)
void setup() {
Serial.begin(115200); // Open serial communications and wait for port to open:
while (!Serial) ;
// start the Ethernet connection:
Serial.println("\n\nInitialize Ethernet (not using DHCP) :");
Ethernet.begin(mac, ip);
delay(1000);
Serial.println(Ethernet.localIP());
Serial.println("connecting to server...");
// Ethernet ready, connect to server and transmit data
if (!client.connect(server, serverPort)) {
Serial.println("connection failed");
while(1);
}
Serial.println("connection OK");
}
// chat server open
// transmit text entered at keyboard to server
// display text received from server
void loop()
{
char ch;
static String receivedLine = "", transmitLine="";
if (client.available())
if((ch = client.read()) != '\n')
receivedLine+=ch; // add to currentline
else {
Serial.println("Received '" + receivedLine + "'");
receivedLine="";
}
if(Serial.available()) // if keyboard test available
if((ch=Serial.read()) != '\n') // if not new line
transmitLine+=ch; // add to currentline
else { // on \n transmit line
Serial.println("transmitting '" + transmitLine + "'");
client.print(transmitLine + "\n");
transmitLine="";
}
}
ran the Java TCPchat server from post #6 on the PC
arduino output
Initialize Ethernet (not using DHCP) :
192.168.1.115
connecting to server...
connection OK
transmitting 'cient test 1'
transmitting '22222222222222222222'
Received 'server test 1
'
Received '22222222222222222
'
Received '
'
transmitting 'client bye'
Received 'server bye
'
var express = require('express'); // include express.js
var app = express(); // a local instance of it
var bodyParser = require('body-parser'); // include body-parser
var WebSocketServer = require('ws').Server // include Web Socket server
// you need a body parser:
app.use(bodyParser.urlencoded({extended: false})); // for application/x-www-form-urlencoded
// this runs after the server successfully starts:
function serverStart() {
var port = server.address().port;
console.log(server.address());
}
// this is the POST handler:
app.all('/*', function (request, response) {
console.log('Got a ' + request.method + ' request');
// the parameters of a GET request are passed in
// request.body. Pass that to formatResponse()
// for formatting:
console.log(request.headers);
if (request.method == 'GET') {
console.log(request.query);
} else {
console.log(request.body);
}
// send the response:
response.send('OK');
response.end();
});
// start the server:
var server = app.listen(8080, serverStart);
// create a WebSocket server and attach it to the server
var wss = new WebSocketServer({server: server});
wss.on('connection', function connection(ws) {
// new connection, add message listener
ws.on('message', function incoming(message) {
// received a message
console.log('received: %s', message);
// echo it back
ws.send(message);
});
});
this will only work if you are using a subnet mask like 255.255.0.0
I assume this is uncommon.
Please post the ipconfig of your laptop (=the server) including the subnet mask.
then fit the ip of your Arduino to the IP range of your server (or in other words - only the last IP octet should differ if you have a subnet mask of 255.255.255.0).
