This laboratory is located in the office of ITT Group in Tallinn, Estonia.

This laboratory can be used to practice displaying messages on the OLED screen.

For this laboratory, the student should understand basic MQTT concepts like topics, broker, subscribing and publishing. Also, knowledge about I2C interface is recommended but not mandatory.

This laboratory consists of an OLED display module attached to the ITT IoT controller module. Oled module contains an organic light-emitting diode, that is a light-emitting diode in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current.

=== Sensors ===Relay This laboratory does not have any sensors.

Connected to ports GPIO4 (SDA) and GPIO5 (SCL).

• ITTIoT libary - used to program the controller module.
• Adafruit GFX library - general libary for Adafruit displays
• Adafruit SSD1306 Wemos Mini OLED - libary for controlling the OLED screen.

The user can connect and program this controller using the Distancelab environment.

At the same time, only one user can program the controller. But all users connected to the Distancelab MQTT broker can subscribe and publish to topics specified.

#include <Arduino.h>
#include <ittiot.h>
#include <Ticker.h>
#include <ESP8266WiFi.h>
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
 
#define OLED_RESET 0  // GPIO0
 
Ticker timeTicker;
Adafruit_SSD1306 display(OLED_RESET);
 
// ITT splashs screen bitmap. Generator: http://javl.github.io/image2cpp/
static const unsigned char PROGMEM logo16_glcd_bmp[] =
{
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0xf0, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x10, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x07, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x07, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x10, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x1f, 0xff, 0xff, 0xc0, 0x00, 
  0x00, 0x00, 0x07, 0x00, 0x00, 0x00, 0xc0, 0x00, 0x00, 0x00, 0x07, 
  0x00, 0x00, 0x00, 0xc0, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00, 
  0xc0, 0x00, 0x00, 0x00, 0x07, 0x1f, 0xe3, 0xff, 0xc0, 0x00, 0x00, 
  0x00, 0x07, 0x1f, 0xe3, 0xff, 0xc0, 0x00, 0x00, 0x00, 0x07, 0x10, 
  0xe2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x10, 0xe2, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x07, 0x10, 0xe2, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x07, 0x10, 0xe3, 0xff, 0xff, 0xf8, 0x00, 0x00, 0x07, 0x10, 0xe0, 
  0x00, 0x00, 0x18, 0x00, 0x00, 0x07, 0x10, 0xe0, 0x00, 0x00, 0x18, 
  0x00, 0x00, 0x07, 0x10, 0xe0, 0x00, 0x00, 0x18, 0x00, 0x00, 0x07, 
  0x10, 0xe3, 0xfc, 0xff, 0xf8, 0x00, 0x00, 0x07, 0x10, 0xe3, 0xfc, 
  0xff, 0xf8, 0x00, 0x00, 0x07, 0x10, 0xe2, 0x1c, 0x80, 0x00, 0x00, 
  0x00, 0x07, 0x10, 0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x07, 0x10, 
  0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x07, 0x10, 0xe2, 0x1c, 0x80, 
  0x00, 0x00, 0x00, 0x07, 0x10, 0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 
  0x07, 0x10, 0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x07, 0x10, 0xe2, 
  0x1c, 0x80, 0x00, 0x00, 0x00, 0x07, 0xf0, 0xe2, 0x1c, 0x80, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0xe2, 0x1c, 
  0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0xe2, 0x1c, 0x80, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0xe2, 0x1c, 0x80, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0xe2, 0x1c, 0x80, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0xfe, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1c, 0x80, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x00, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1c, 
  0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1c, 0x80, 0x00, 0x00, 
  0x00, 0x00, 0x00, 0x00, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 
  0x00, 0x1c, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1f, 0x80, 
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
 
#if (SSD1306_LCDHEIGHT != 48)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif
 
bool isBootModeNormal;
bool sendDataFlag;
 
int i = 0;
 
// Ticker library callback, which will occur 0.5 second interval.
void sendData()
{
  sendDataFlag=true;
}
 
// Function started after the connection to the server is established.
void iot_connected()
{
  Serial.println("MQTT connected callback");
  iot.log("IoT OLED screen example!");
  isBootModeNormal = true;
}
 
void setup()
{
  Serial.begin(115200);
  Serial.println("Booting");
 
  // initialize with the I2C addr 0x3C (for the 64x48)
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
 
  // Since the buffer is intialized with an Adafruit splashscreen
  // internally, we should clear it
  display.clearDisplay();
 
  // Load ITT splash screen into buffer
  display.drawBitmap(0, 0,  logo16_glcd_bmp, 64, 48, 1);
  // Show image buffer on the display
  display.display();
 
  // Display splashscreen two second
  delay(2000);
 
  // print IoT json config to serial
  iot.printConfig();
 
  // Initialize IoT library
  iot.setup();
 
  // Initialize Ticker interval and callback
  timeTicker.attach(0.5, sendData);
}
 
void loop()
{
  // IoT behind the plan work, it should be periodically called
  iot.handle();
 
  // Increase counter value
  i++;
 
  // Display counter value and boot mode on the OLED screen
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0,0);
  display.println("Counter: ");
  display.println(i);
 
  display.setCursor(0,30);
 
  if(isBootModeNormal)
  {
    display.println("Mode: NORM");
  }
  else
  {
    display.println("Mode: BOOT");
  }
 
  display.display();
 
  // Send counter value to the server
  if(WiFi.isConnected() && isBootModeNormal)
  {
    if(sendDataFlag)
    {
      sendDataFlag = false;
      String msg = String(i);
      iot.publishMsg("count", msg.c_str());
      Serial.println(msg);
    }
  }
}

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