esp8266_ethernet

Example of using SPI Ethernet module with esp8266.
Arduino core for ESP8266 uses lwip for TCP/IP protocol stack.
The hierarchy of programs that use WiFi is as follows:

+----------------+
|  Application   |
+----------------+
| Network Object |
+----------------+
|      lwip      |
+----------------+
|   WiFi Driver  |
+----------------+ 

Arduino Core for ESP8266 Ver3.0.2 officially supports SPI External Ethernet.
You don't need any libraries.
The hierarchy of programs that use Ethernet is as follows:

+----------------+
|  Application   |
+----------------+
| Network Object |
+----------------+
|      lwip      |
+----------------+
| Ethernet Driver|
+----------------+

Hardware requiment

SPI Ethernet module using this chip.

• ENC28J60
• W5100
• W5500

Software requiment

• Arduino core for ESP8266 V3.0.2 or later
  
  You can check the Core version using ESP.getFullVersion() or ESP.getCoreVersion().
  This is mine:

ESP.getFullVersion=SDK:2.2.2-dev(38a443e)/Core:3.0.2=30002000/lwIP:STABLE-2_1_2_RELEASE/glue:1.2-48-g7421258/BearSSL:6105635
ESP.getCoreVersion=3.0.2

Wireing

SPI PHY	---	ESP8266
SCK	---	GPIO14(D5)
MISO	---	GPIO12(D6)
MOSI	---	GPIO13(D7)
CS	---	GPIO16(D0)(*)
RST	---	RESET
3.3V	---	3.3V
GND	---	GND

(*) You can change it to any GPIO.

Selecting the Ethernet module

• Using W5500:

#include <W5500lwIP.h>
Wiznet5500lwIP eth(CSPIN);

• Using W5100:

#include <W5100lwIP.h>
Wiznet5100lwIP eth(CSPIN);

• Using ENC28J60:

#include <ENC28J60lwIP.h>
ENC28J60lwIP eth(CSPIN);

Using PlatformIO

$ git clone https://github.com/nopnop2002/esp8266_ethernet

$ cd esp8266_ethernet/connectEthernet/

$ pio init -b d1_mini

$ cp connectEthernet.ino src/

$ pio run -t upload && pio device monitor -b 115200

==================================== [SUCCESS] Took 25.50 seconds ====================================
--- Available filters and text transformations: colorize, debug, default, direct, esp8266_exception_decoder, hexlify, log2file, nocontrol, printable, send_on_enter, time
--- More details at https://bit.ly/pio-monitor-filters
--- Miniterm on /dev/ttyUSB0  115200,8,N,1 ---
--- Quit: Ctrl+C | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---

SDK:2.2.2-dev(38a443e)/Core:3.0.2=30002000/lwIP:STABLE-2_1_2_RELEASE/glue:1.2-48-g7421258/BearSSL:6105635
connecting ethernet..
ethernet ip address: 192.168.10.128
ethernet subnetMask: 255.255.255.0
ethernet gateway: 192.168.10.1

How to convert from WiFi to Ethernet

• WiFi

#include <ESP8266WiFi.h>

const char* SSID = "ssid_of_your_router";
const char* PASSWORD = "password_of_your_router";

void setup() {
  delay(1000);
  Serial.begin(115200);
  Serial.println();
  Serial.print(ESP.getFullVersion());
  Serial.println();

  Serial.print("connecting wifi");
  WiFi.mode(WIFI_STA);
  WiFi.begin(SSID, PASSWORD);
  while (1) {
    uint8_t status = WiFi.status();
    Serial.print("status=");
    Serial.println(status);
    if (status == WL_CONNECTED) break;
    Serial.print(".");
    delay(500);
  }
  Serial.println();
  Serial.print("WiFi ip address: ");
  Serial.println(WiFi.localIP());
  Serial.print("Wifi subnetMask: ");
  Serial.println(WiFi.subnetMask());
  Serial.print("WiFi.gatewayIP: ");
  Serial.println(WiFi.gatewayIP());
  Serial.print("WiFi.dnsIP: ");
  Serial.println(WiFi.dnsIP());

}

void loop() {
}

• Ethernet

#include <SPI.h>
#include <ESP8266WiFi.h>
#include <W5500lwIP.h>
//#include <W5100lwIP.h>
//#include <ENC28J60lwIP.h>

#define CSPIN 16

Wiznet5500lwIP eth(CSPIN);
//Wiznet5100lwIP eth(CSPIN);
//ENC28J60lwIP eth(CSPIN);
byte mac[] = {0x00, 0xAA, 0xBB, 0xCC, 0xDE, 0x02};

void setup() {
  delay(1000);
  Serial.begin(115200);
  Serial.println();
  Serial.print(ESP.getFullVersion());
  Serial.println();

  SPI.begin();
  SPI.setBitOrder(MSBFIRST);
  SPI.setDataMode(SPI_MODE0);
  SPI.setFrequency(4000000);

  eth.setDefault(); // use ethernet for default route
  int present = eth.begin(mac);
  if (!present) {
    Serial.println("no ethernet hardware present");
    while(1);
  }
  
  Serial.print("connecting ethernet");
  while (!eth.connected()) {
    Serial.print(".");
    delay(1000);
  }
  Serial.println();
  Serial.print("ethernet ip address: ");
  Serial.println(eth.localIP());
  Serial.print("ethernet subnetMask: ");
  Serial.println(eth.subnetMask());
  Serial.print("ethernet gateway: ");
  Serial.println(eth.gatewayIP());
}

void loop() {
}

WiFi examples

https://github.com/esp8266/Arduino/tree/master/libraries/ESP8266WiFi/examples