esp via mqtt with an oled node-red

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// not available on ESP-01, but needed in the code
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

const char* ssid = "SSID";      // ssid
const char* password = "password";  // password
const char* mqtt_server = "10.0.0.10";    // mqqt server
const char* inTopic = "inTopic";                // topic esp will subscribe to
const char* clientId = "esp-testing";                // id of the esp

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;


void setup()
{
  // set gpio0 and gpio2 as sda, scl
  Wire.begin(0,2);
  // initialize with the I2C addr 0x3C (for the 128x32)(initializing the display)
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  Serial.begin(9600);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}


void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}


void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  String message = (char*)payload;

  // if payload = X
//  if ((char)payload[0] == '1') {
  // on any payload
  if ((char)payload[0]) {
    // do stuff
    display.clearDisplay();
  // oled will wrap lines, single line stops at U, lol, at you get it...
//  display.print("abcdefghijklmnopqrstuvwxyz");
    display.setTextColor(WHITE);
    display.setTextSize(1);
    display.setCursor(0,0);
    // print the message we get from mqtt
    display.print(message);
  // if payload = 0, using this to clear the line
  } else if ((char)payload[0] == '0') {
    // do stuff
    display.clearDisplay();
    display.setTextColor(BLACK);
    display.setTextSize(1);
    display.setCursor(0,0); 
    display.print("....................."); 
  }
}


void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect(clientId)) {
      Serial.println("connected");
      // Once connected, publish an announcement...
//      client.publish("outTopic", "hello world");
      // ... and resubscribe
      client.subscribe(inTopic);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}


void displayTempHumid(){
  delay(2000);

  display.clearDisplay();
  display.setTextColor(WHITE);
  display.setTextSize(1);
  display.setCursor(0,0);
  display.print("Humidity: "); 
  display.print("10");
  display.print(" %\t");
  display.setCursor(0,10);
  display.print("Temperature: "); 
  display.print("71");
  display.print(" F"); 
  display.setCursor(0,20);
  display.print("Temperature: "); 
  display.print("53");
  display.print(" F"); 
}


void loop()
{
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  
//  displayTempHumid();
  display.display();
}