Powered by Blogger.

Thursday, 24 December 2015

Circuit to interface HC-05 bluetooth module to Arduino uno

by realfinetime  |  in HC-05 at  09:37

Household equipment such as bulb or fan controlled using your android device is an interesting project which most hobbyists want to do. A communication should be there between the android device and household equipment through some microcontroller boards such as Arduino uno. Bluetooth is a simple method to establish a communication between android device and household equipment. Here, I am using a HC-05 bluetooth module to communicate with android device. HC-05 is connected to Arduino uno to receive the data sent from android device. Depending on the data received from android device, we can use this Arduino uno to control our household equipment.
Connections are done as shown in the following diagram. Connections can be summarized as,
  1. 5V pin of Arduino uno is connected to the VCC terminal of HC-05 bluetooth module.
  2. Gnd pin of Arduino uno is connected to the Gnd terminal of HC-05 bluetooth module.
  3. RX pin of Arduino uno is connected to the TX terminal of HC-05 bluetooth module.
  4. TX pin of Arduino uno is connected to the RX terminal of HC-05 bluetooth module.

After completing the circuit, upload the following program to your Arduino board. Disconnect RX and TX pins connected to Arduino uno for successful uploading. Otherwise, uploading will be failed. After successful uploading, reconnect the RX and TX pins.

char junk;
String inputString="";

void setup()
  while (!Serial);

void loop()
      char inChar = (char); //read the input
      inputString += inChar;             //make a string of the characters coming on serial
    while (Serial.available() > 0)  
      junk = ; 
    inputString = "";

Now, open the serial monitor from Arduino IDE. Nothing will be displayed in the serial monitor. Still, you must keep the serial monitor open until the remaining steps also get completed.

Next steps will be in your android device. Install Bluetooth Terminal application in your android device from Google Play Store.

After installing, open Bluetooth Terminal application and connect your android device to bluetooth device HC-05.
Select your bluetooth device from a list of available devices.
If connection goes successful, your Bluetooth Terminal will be as shown below.
Now, type letters in the text box and send.
Letters sent from your android device will be displayed in the serial monitor of Arduino.


  1. But how those letters control home equipment?

  2. Winters are almost ending and spring is almost here. This painting is soo beautiful it reminds of the blossoming of spring amd its vibrant and sparkling colours

  3. I admire this article for the well-researched content and excellent wording. I got so involved in this material that I couldn’t stop reading. I am impressed with your work and skill. Thank you so much.
    android development company in chennai

  4. I am glad that I saw this post. It is informative blog for us and we need this type of blog thanks for share this blog, Keep posting such instructional blogs and I am looking forward for your future posts.
    IEEE Final Year Projects Quantum Computing Domain

    JavaScript Training in Chennai

    Project Centers in Chennai

    JavaScript Training in Chennai

  5. It's very Pleasure to Visit your Site...The Effective Information's about Corporate Training course are Posted Here...It's Really Good.Thanks for Such an wonderful works...
    Java training in chennai | Java training in annanagar | Java training in omr | Java training in porur | Java training in tambaram | Java training in velachery

  6. It's very useful article with inforamtive and insightful content and i had good experience with this information.Enroll today to get free access to our live demo session which is a great opportunity to interact with the trainer directly which is a placement based Salesforce training India with job placement and certification . I strongly recommend my friends to join this Salesforce training institutes in hyderabad practical course, great curriculum Salesforce training institutes in Bangalore with real time experienced faculty Salesforce training institutes in Chennai. Never delay to enroll for a free demo at Salesforce training institutes in Mumbai who are popular for Salesforce training institutes in Pune.

  7. Gone through this wonderful coures called Salesforce Certification Training in Dallas who are offering fully practical course, who parent is Salesforce Training in USA and they have students at Salesforce Training classes in Canada institutes.



All the circuits, published in this blog is only after testing and getting proper results in my private lab. When you try these circuits, you should check the supply voltage, polarity of components, presence of childrens nearby and shorts in the circuits. This website will not be responsible for any harm happened to you or your components caused by your carelessness.

For More Electronic Tips

Proudly Powered by Blogger.