How to use console.log message from nodejs server, to control led pin 13?

Question

I want to use Arduino Yun as a client, that connects to my nodejs server, receives a message from nodejs and then change led pin 13 on/off according to the message send.

I have this example of a nodejs server:

  var express = require('express');
var http = require('http');
var url = require('url');                       

var app = express();

//app.set('port', 8080);

var server = http.createServer(function(request, response){             
    console.log('Connection');                                                          var path = url.parse(request.url).pathname;                                 

    switch(path){                                               
        case'/':
            response.writeHead(200, {'Content-Type': 'text/html'});     
            response.write('Hello World');                          
            response.end();
            break;
        case '/arduino/digital/13/0':
            response.writeHead(200, {'Content-Type': 'text/html'});     
            response.write('Led 13 is off');                        
            console.log('Led 13 is off');
            response.end();
            break;
        case '/arduino/digital/13/1':
            response.writeHead(200, {'Content-Type': 'text/html'});
            response.write('Led 13 is on');
            console.log('Led 13 is on');
            response.end();
            break;
        default:
            response.writeHead(404);
            response.write("Oops, this doesn't exist - 404");   
            response.end();                                                     
            break;
    }

});

//server.listen(8080);

var server_port = process.env.OPENSHIFT_NODEJS_PORT || 8080
var server_ip_address = process.env.OPENSHIFT_NODEJS_IP || '127.0.0.1'

server.listen(server_port, server_ip_address, function () {
  console.log( "Listening on " + server_ip_address + ", server_port " + server_port )
});

The server is running on an openshift nodejs server - It's not Localhost!

Here is the Arduino sketch I use:

/*
 Possible commands created in this shetch:
 * "http://yunobomber-cuebo.rhcloud.com"                         -> Serial Monitor "Hello World"
 * "http://yunobomber-cuebo.rhcloud.com/arduino/digital/13/1"    -> Serial Monitor "Led 13 is on"  &  digitalWrite(13, HIGH)
 * "http://yunobomber-cuebo.rhcloud.com//arduino/digital/13/0"   -> Serial Monitor "Led 13 is off" &  digitalWrite(13, LOW)
 */

#include <Bridge.h>   
#include <HttpClient.h>

HttpClient client;

void setup() {
  Bridge.begin();                                                          // Bridge startup

  Serial.begin(9600);
  while (!Serial);                                                         // wait for a serial connection
}

void loop() {
  // Initialize the client library
  HttpClient client;

  // Make a HTTP request:
  client.get("http://yunobomber-cuebo.rhcloud.com");       // Insert alternative url for other commands - See explanation at top

  while (client.available()) {                             // Read message from server
    char c = client.read();
    Serial.print(c);
  }
  Serial.flush();
  delay(5000);
}

void process(HttpClient client) {
  String command = client.readStringUntil('/');

  if (command == "digital") {
    digitalCommand(client);
  }
}

void digitalCommand(HttpClient client) {
  int pin, value;

  // Read pin number
  pin = client.parseInt();

  // If the next character is a '/' it means we have an URL
  // with a value like: "/digital/13/1"
  if (client.read() == '/') {
    value = client.parseInt();
    digitalWrite(pin, value);
  }
  else {
    Serial.println('Error: Could not read url!');
  }
}

The serve works as it should, which can be seen here: http://yunobomber-cuebo.rhcloud.com

I'm also get the message send from the server, when I read serial monitor, so the connection to the server from the Yun is also working. I can also console.log on the server side and see that a connection is established from the Yun.

The problem seems to be with the readStringUntil(); method, what I want to do is actually readStringAfter(arduino/), but such a method doesn't exist or at least I'm not sure how to make one?

Also I wonder if my approach is wrong, since I use REST calls to control the Yun, maybe I should solve it diffenrently, since I've already established a connection to and receiving input from the nodejs server?

Hope that someone can help my understand and solve this issue?

How to use console.log message from nodejs server, to control led pin 13?

0 Answers0