Lab_interaccio/2019/GIGANTES-MERCE/websocket-client/mWebSockets

μWebSockets

Simple to use implementation of WebSockets for microcontrollers.

List of supported IDEs:

• Arduino
• Visual Studio Code with Platformio

List of supported MCUs:

• ATmega328P
• ATmega2560
• ARM Cortex M0
• ESP8266

The Autobahn|Testsuite reports for server and client

Some tests will never pass just because of memory lack in ATmega family.

Table of contents

• Requirements
• Installation
  • config.h
  • Physical connection
• Usage examples
  • Server
  • Client
  • Chat
• Approx memory usage
• Ethernet "2" library modification
  • Fix for Arduino Mega
• Fix for arduino-base64 with ESP8266
• Known issues
• License

Requirements

• Development board (confirmed working, other boards may or may not work):
  • Arduino Uno (ATmega328P)
  • Arduino Pro Mini (ATmega328P)
  • Arduino Mega2560
  • Arduino Zero / SAMD21 M0 (ARM Cortex M0)
  • WeMos D1 mini (ESP8266)
  • NodeMCU v3 (ESP8266)
• Ethernet module or shield (confirmed working):
  • Arduino Ethernet Shield W5100
  • WizNet W5500 module
  • ENC28j60
• Libraries:
  • arduino-base64
  • CryptoLegacy from arduinolibs, you can grab it from here
  • Ethernet "2" for W5500
    • This library is deprecated you can use official Arduino Ethernet library.
  • UIPEthernet #1 or #2 (the choice is yours) for ENC28j60

Installation

Install this library, arduino-base64 and CryptoLegacy in Arduino libraries directory, follow this guide if you don't know how to do it.

config.h

Change below definition if you use a different controller:

...

#define NETWORK_CONTROLLER ETHERNET_CONTROLLER_W5100

ETHERNET_CONTROLLER_W5100
ETHERNET_CONTROLLER_W5500
ETHERNET_CONTROLLER_ENC28J60
NETWORK_CONTROLLER_WIFI

ETHERNET_CONTROLLER_W5100 means official Arduino Ethernet library. It is possible to use this with both W5100 and W5500. ETHERNET_CONTROLLER_W5500 stands for Ethernet "2" library.

Uncomment these if you want additional informations in serial monitor:

//#define _DEBUG
//#define _DUMP_HANDSHAKE
//#define _DUMP_FRAME_DATA
//#define _DUMP_HEADER

Increase below value if you expect big data frames (or decrease for devices with small amount of memory)

#define BUFFER_MAX_SIZE 256

Physical connection

W5100 Ethernet shield	Arduino Uno / Mega2560	Arduino Pro Mini	Arduino Zero
(ICSP) MISO	(ICSP) MISO	PIN 12	(ICSP) MISO
(ICSP) MOSI	(ICSP) MOSI	PIN 11	(ICSP) MOSI
(ICSP) SCK	(ICSP) SCK	PIN 13	(ICSP) SCK
(SS) PIN 10	PIN 10	PIN 10	PIN 10

W5500 / ENC28j60	Arduino Uno / Pro Mini	Arduino Mega2560
MISO	PIN 12	PIN 50
MOSI	PIN 11	PIN 51
SCS	PIN 10	PIN 53
SCLK	PIN 13	PIN 52

Usage examples

Server

#include <WebSocketServer.h>
using namespace net;

WebSocketServer server(3000);

void setup() {
  // Ethernet/WiFi initialization goes here ...
  // ...

  server.onConnection([](WebSocket &ws) {
    char message[] = "Hello from Arduino server!";
    ws.send(message, strlen(message));
    
    ws.onClose([](WebSocket &ws, const WebSocketCloseCode code, const char *reason, uint16_t length) {
      // ...
    });
    ws.onMessage([](WebSocket &ws, WebSocketDataType dataType, const char *message, uint16_t length) {
      // ...
    });
  });
 
  server.begin();
}

void loop() {
  server.listen();
}

Node.js server examples here

Client

#include <WebSocketClient.h>
using namespace net;

WebSocketClient client;

void setup() {
  // Ethernet/WiFi initialization goes here ...
  // ...
  
  client.onOpen([](WebSocket &ws) {
    char message[] = "Hello from Arduino client!";
    ws.send(message, strlen(message));
  });
  client.onClose([](WebSocket &ws, const WebSocketCloseCode code, const char *reason, uint16_t length) {
    // ...
  });
  client.onMessage([](WebSocket &ws, WebSocketDataType dataType, const char *message, uint16_t length) {
    // ...
  });
  
  client.open("host", 3000);
}

void loop() {
  client.listen();
}

Chat

Following screenshots shows Rasperry Pi server, browser client and Arduino client in action:

Node.js server on Raspberry Pi (/node.js/chat.js)

Browser client (/node.js/chat-client.htm)

Arduino Uno client (/examples/chat/chat.ino)

More examples here

Approx memory usage

*simple-client.ino example (without debug output)

Ethernet.h (W5100 and W5500)

Board	Program space	Dynamic memory
Arduino Uno	24538 bytes (76%)	1012 bytes (49%)
Arduino Mega2560	24836 bytes (9%)	1048 bytes (12%)
Arduino Pro Mini	24538 bytes (79%)	1012 bytes (49%)
Arduino Zero	28308 bytes (10%)

Ethernet2.h (W5500)

Board	Program space	Dynamic memory
Arduino Uno	21592 bytes (66%)	811 bytes (39%)
Arduino Mega2560	21900 bytes (8%)	811 bytes (9%)
Arduino Pro Mini	21592 bytes (70%)	811 bytes (39%)
Arduino Zero	25988 bytes (9%)

UIPEthernet.h (ENC28j60)

⚠️ This library is incompatibile with Arduino Zero! ⚠️

Board	Program space	Dynamic memory
Arduino Uno	29762 bytes (92%)	1659 bytes (81%) ⚠️
Arduino Mega2560	30172 bytes (11%)	1659 bytes (20%)
Arduino Pro Mini	29762 bytes (96%)	1659 bytes (81%) ⚠️

WiFi

Board	Program space	Dynamic memory
Generic ESP8266	265864 bytes (53%)	33644 bytes (41%)
WeMos D1 mini	265864 bytes (25%)	33644 bytes (41%)
NodeMCU	265864 bytes (25%)	33624 33644 (41%)

Ethernet "2" library modification

Fix for Arduino Mega

Ethernet2.h

#if defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168__)
  EthernetClass() { _dhcp = NULL; w5500_cspin = 10; }
  void init(uint8_t _cspin) { w5500_cspin = _cspin; }
#elif defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
  EthernetClass() { _dhcp = NULL; w5500_cspin = 53; }
  void init(uint8_t _cspin = 53) { w5500_cspin = _cspin; }
#endif

Fix for arduino-base64 with ESP8266

Move files: Base64.h and Base64.cpp to src directory of ArduinoWebSockets library. In Base64.cpp change:

#include <avr/pgmspace.h>

to this:

#include "platform.h"
#include "Base64.h"
#if PLATFORM_ARCH == PLATFORM_ARCHITECTURE_ESP8266
#include <pgmspace.h>
#else
#include <avr/pgmspace.h>
#endif

Known issues

1. ENC28j60 is slow, eats much more memory than W5100/W5500 and hangs on available() function

License

This project is licensed under the MIT License - see the LICENSE file for details