I am trying to get my core to call a url when it starts.
To do that I am using this code
TCPClient client;
char url[] = "http://server.com";
char initReq[] = "GET /folder/file.php";
int port = 80;
void setup()
{
//Register our Spark function here
Spark.function("SWITCH", pinSwitch);
if(client.connect(url, port))
{
String request = initReq + String("?spark=") + Spark.deviceID();
client.println(request);
client.print("HOST: ");
client.println(url);
client.println("Connection: close");
client.println();
client.flush();
}
}
void loop()
{
// Nothing to do here
}
int pinSwitch(String command)
{
int state = 0;
//find out the pin number and convert the ascii to integer
int pinNumber = command.charAt(1) - '0';
//Sanity check to see if the pin numbers are within limits
if (pinNumber < 0 || pinNumber > 7)
{
return -1;
}
// find out the state of the led
if(command.substring(3,7) == "HIGH")
{
state = 1;
}
else if(command.substring(3,6) == "LOW")
{
state = 0;
}
else
{
return -2;
}
// write to the appropriate pin
pinMode(pinNumber, OUTPUT);
digitalWrite(pinNumber, state);
return 1;
}
But it does not seem to work, the url it calls should look like
TCPClient provides you with a raw TCP connection, so a URI will not work.
You will have to implement a basic HTTP client on top of TCPClient to make a GET request.
You have part of that implemented (Host: Connection: headers) but youâre missing HTTP/1.1 after your URI. It also needs to be terminated with â\r\n\r\nâ
The request should be constructed like the following after establishing a TCP connection with the web server.
GET /folder/file.php?spark=abcd HTTP/1.1\r\n
Host: server.com\r\n
Connection: close\r\n
\r\n
@Mikey Do you mean, âbreakâ or âcontinueâ ?? Because âcontinueâ would let the loop carry on right?
And as far Iâve tried the longer it takes to read characters from the Client or from a Server, the chances of it hanging up are higher. Thanks for that
I first got back to using it today, and I canât get it to work at all.
I see the led changing, which means it goes into the function where it connects to my server and sends the data, but my server does not receive anything, and the led changes back to breathing again right away too.
The code I am using is something I have used before, but it does not seem to work any longer.
With http requests from the core, I think putting a short delay delay(100) after your client.stop() can help make things more consistent. Lemme know if that works!
unsigned long lastSync = 0;
void nodeSync()
{
if ((millis() - lastSync < 3600000 && lastSync != 0) && millis() >= lastSync) return; //Only check once every hour, unless we havent checked yet, or if time since overflow of millis is less than last time we checked
lastSync = millis();
RGB.control(true);
TCPClient client;
byte server[] = { xxx, xxx, xxx, xxx };
if (client.connect(server, 80))
{
RGB.color(255, 0, 0);
String tsData = String(Spark.deviceID());
client.println("GET /folder/file.php?spark=" + tsData + " HTTP/1.1");
client.println("Host: server.com");
client.println("Connection: close");
client.println();
while (client.available()) //Read what is returned from the server
{
char c = client.read();
if (millis() - lastSync > 500) break; //Read for maximum 500ms, then stop reading
}
client.flush();
client.stop();
delay(100);
}
RGB.control(false);
}
and I see the led change to red, then back to breathing again, but the server does not seem to get anything.
@Mikey Are you uploading the code from the Web IDE or locally? If youâre doing it locally can you try using the latest firmware.
Also maybe you could try to reduce your interval of HTTP requests from 1 hour to say 10 seconds and see if your server picks up at least a few of the many requests you are sending.
Iâm highly uncertain about this but I see a tiny problem within the code (Please correct me if Iâm wrong). You seem to be creating a new âtcpClientâ object inside every call to the function ânodeSyncâ. I wonder if this might be causing the core to run into problems with the number of sockets opened.
Tried to have a look in the apache log, and it looks like something is getting through now, however it seems to return status code 400 (Bad Request) so looks like it is trying to get hold of a wrong host maybe?
Not sure if your webserver is set to respond to âserver.comâ or if you replaced the hostname in your code, but often webservers arenât configured to do wildcard hosting. Maybe make sure to change âserver.comâ to match what your server thinks its hostname is?
Firstly, I had faced issues with client.println() the other day when I was doing non-http tcp requests to server at port 8888. When I used client.write(buff, length) it worked fine. However do this as a last resort since almost everyone is using client.println() successfully.
Secondly and more likely, I think you are closing the connection before you get a TCP Response back from the server. Usually when a browser/app/script makes a TCP request, thereâs a timeout/wait period of 2-10 seconds before the client closes the connection.
So you could probably include the following before you do your while(client.available()) :
unsigned long timeoutTimer = millis();
while(millis() - timeoutTimer < 2000){
if(client.available()){
break; // received response from server - stop waiting
}
}
while(client.available())... YOUR CODE Continues
I am using println so the \r\n seems to be inserted already.