DHT11 Sensor With OLED & Bluetooth Part 3

In this project, we will be making a "DHT11 Sensor with OLED & Bluetooth." In part 1, we display the temperature in Celsius and Fahrenheit with a thermometer animation. In part 2 we display the temperature in Celsius and Fahrenheit but we remove the thermometer animation and add the humidity value. In this part, we will be able to see the temperature and humidity on the OLED as well as on the App. The HC-05 Bluetooth module will connect to the app and from there that app will display the data. We write some code so that the Arduino can receive the temperature and humidity from the sensor. Once we have the temperature, we convert it to Fahrenheit ((Celcius * 1.8) + 32). We then customize the OLED screen to display the temperature in Fahrenheit by default but we can change it to Celsius from the App.

This project can still be improved.

The components required to make this project are:

• Arduino IDE
• Arduino Nano
• 0.96" SSD1306 128X64 OLED
• DHT11 Temperature & Humidity Sensor
• HC-05 Bluetooth Module
• Breadboard
• Jumper Wires

Connect the DHT11 as following:

Arduino >> DHT11

GND >> GND

5V >> VCC

A0 >> Signal

Connect the HC-05 as following:

Arduino >> HC-05

GND >> GND

5V >> VCC

D3 >> TXD

D2 >> RXD

Connect the OLED as following:

Arduino >> OLED

GND >> GND

5V >> VCC

A4 >> SDA

A5 >> SCL

Open the program on Arduino IDE. Once it is open, compile the sketch to see if it is clear of error and upload it. Make sure you have all the libraries download before you upload the program. After uploading the program, you should see the screen turn on and display "AI." After 3 seconds, it will display the temperature in Fahrenheit and the humidity.

For more information about this, please visit my Patreon:

https://www.patreon.com/acedinventor

I have made the app in MIT APP INVENTOR. You don't have to make the app because I have provided the .apk file for the app. The app is called "DHT11.apk."

To test if the project is working properly, check the temperature the DHT11 is displaying on the OLED screen and check the thermometer in your house and see if they match. If they don't, there could be a possibility that the room the sensor is in is warmer or colder, which is why the temperatures are not matching. You can also test the sensor by putting a piece of ice on it and see if the temperate is dropping. You can also connect the HC-05 over Bluetooth to the app. The values on the app should be updating live. You can also change the temperature being displayed on the app from Fahrenheit to Celsius from the app. Click on the settings icon, then click on Fahrenheit or Celsius. Whichever one you choose will be displayed on the OLED.

If there is still something you don't understand, you can comment down below.