No Websockets Server for Arduino mkr1010?

Question

I've seen some interesting explanations on using websocket comms on mkr 1010 but it's always handling the mkr 1010 as the client and the server being always a computer or some other "non-arduino" server . I'm working on a system with several mkr 1010's in a master/slave setup and bidi comms i.e. i want to use one of the mkr's as a server (does the calculations etc.) and the other as clients (get result from calculations ans send back sensor info). I did not found any library or example of websocket server for mkr1010. I found it for ESP systems. Please help as i tried my bidi comms with webclient and webserver using http but not good enough for my applicaton (not realy bidi). thanks a lot !

Answer 1

Most websocket libraries work over a Client. Client is base class for all EthernetClient and WiFiClient classes.

But why do you want to use a Websocket for communication of two MCU in the same LAN? Websockets are intended for communication over HTTP infrastructure (firewalls, proxies) to a web server in Internet or from browser to a web server.

Use a basic TCP socket over Arduino Client.

WiFiClient object wraps a TCP socket. A normal TCP socket is connected to IP address and port. WiFiServer starts a listening socket on a port. If server on listening socket is contacted by a remote client socket, it creates a local socket connected with the remote client socket on a free port and returns a WiFiClient object wrapping the socket. Everything you write or print to a WiFiClient is send to that one remote socket.

If one of your client boards creates a WiFiClient and connects it to IP address and port of the WiFiServer on your 'server' board, then you get there a WiFiClient from server.available() and this two WiFiClient objects are connected. What you write/print on one side you read only from the WiFiClient object on the other side.

client socket

if (client.connect(serverIP, PORT)) {
  client.print("request\n");
  String response = client.readStringUntil('\n');
  Serial.println(response);
  client.stop();
}

server side

WiFiClient client = server.available();
if (client && client.connected()) {
  String request = client.readStringUntil('\n');
  Serial.println(request);
  client.print("response\n");
  client.stop();
}