Gemma Lee
Published © MIT

W5300 TOE Shield Tutorial: Controlling an LED

Controlling an LED via Cloud with W5300 TOE Shield and Arduino IDE.

BeginnerFull instructions provided1 hour236
W5300 TOE Shield Tutorial: Controlling an LED

Things used in this project

Hardware components

WIZnet W5300-TOE-Shield
×1
Nucleo 144 STM32F7
ST STM32L4, STM32F7 Nucleo 144 STM32F7
STM32 Nucleo-F429ZI Board
×1
LED (generic)
LED (generic)
×1

Software apps and online services

Arduino IDE
Arduino IDE
Beebotte

Story

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Code

Controlling LED in Beebotte using W5300-TOE-Shield

C/C++
#include <SPI.h>
#include <Ethernet.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>
#include "HardwareSerial.h"

#define LEDPIN 13 // Pin which is connected to LED.

//#define BBT "54.221.205.80"         // Domain name of Beebotte MQTT service
#define TOKEN "token_xxxxxxxxx"  // Set your channel token here

#define CHANNEL "NucleoF429ZI"  // Replace with your device name
#define LED_RESOURCE "led"

// Enter a MAC address of your shield
// It might be printed on a sticker on the shield
byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
byte g_target_ip[] = {54, 221, 205, 80};
IPAddress ip(000, 000, 000, 000);
IPAddress myDns(000, 000, 000, 000);
IPAddress gateway(000, 000, 000, 000);
IPAddress subnet(000, 000, 000, 000);

EthernetClient ethClient;
PubSubClient client(ethClient);

// to track delay since last reconnection
long lastReconnectAttempt = 0;

const char chars[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";

char id[17];

const char* generateID() {
  randomSeed(analogRead(0));
  int i = 0;
  for (i = 0; i < sizeof(id) - 1; i++) {
    id[i] = chars[random(sizeof(chars))];
  }
  id[sizeof(id) - 1] = '\0';

  return id;
}

// will be called every time a message is received
void onMessage(char* topic, byte* payload, unsigned int length) {

  // decode the JSON payload
  StaticJsonDocument<256> doc;

  // Test if parsing succeeded
  auto error = deserializeJson(doc, payload);
  if (error) {
    Serial.print(F("deserializeJson() failed with code "));
    Serial.println(error.c_str());
    return;
  }

  // led resource is a boolean read it accordingly
  bool data = doc["data"];

  // Print the received value to serial monitor for debugging
  Serial.print("Received message of length ");
  Serial.print(length);
  Serial.println();
  Serial.print("data ");
  Serial.print(data);
  Serial.println();

  // Set the led pin to high or low
  if (data == 0) {
    digitalWrite(LEDPIN, LOW);
  } else if (data == 1) {
    digitalWrite(LEDPIN, HIGH);
  }
  // digitalWrite(LEDPIN, data ? HIGH : LOW);
}

// reconnects to Beebotte MQTT server
boolean reconnect() {
  if (client.connect(generateID(), TOKEN, "")) {
    char topic[64];
    sprintf(topic, "%s/%s", CHANNEL, LED_RESOURCE);
    client.subscribe(topic);

    Serial.println("Connected to Beebotte MQTT");
  }
  return client.connected();
}

void setup() {
  pinMode(LEDPIN, OUTPUT);

  client.setServer(g_target_ip, 1883);
  client.setServer(BBT, 1883);
  // Set the on message callback
  // onMesage function will be called
  // every time the client received a message
  client.setCallback(onMessage);

  // Open serial communications and wait for port to open:
  Serial3.setRx(PC11);
  Serial3.setTx(PC10);  
  delay(50);
  Serial.begin(9600);
  while (!Serial) {
    ;  // wait for serial port to connect. Needed for native USB port only
  }

  // Ethernet.init(17);

  // start the Ethernet connection:
  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
    // try to congifure using static IP address instead of DHCP:
    // Feel free to change this according to your network settings
    // IPAddress ip(192, 168, 56, 177);
    Ethernet.begin(mac, ip, myDns, gateway, subnet);
  }
  // give the Ethernet shield a second to initialize:
  delay(1000);
  Serial.println("connecting...");
  lastReconnectAttempt = 0;
}

void loop() {
  if (!client.connected()) {
    // Serial.println("NOT CONNECTED");/
    long now = millis();
    if (now - lastReconnectAttempt > 5000) {
      lastReconnectAttempt = now;
      // Attempt to reconnect
      if (reconnect()) {
        lastReconnectAttempt = 0;
      }
    }
  } else {
    // Client connected
    // Serial.println("CONNECTED");/
    client.loop();
  }
}

Credits

Gemma Lee
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  • ST STM32L4, STM32F7
  • WIZnet