HC 05 Bluetooth Module not connecting to MIT app defined in ROINCO arduino multipurpose kit

Hi there, I am a beginner and I bought a kit (ROINCO arduino multipurpose kit), I got the online video tutorials here (https://roboindia.com/tutorials/arduino-multipurpose-kit/), in the 3rd tutorial (Bluetooth Car) I did everything correctly, my bluetooth module led light was blinking, i installed the app given in my phone (Galaxy A12), paired (didn't connect) with HC-05, the light still blinked, I opened the app and pressed scan, selected the HC-05 module, the app stopped responding and exited, I tried multiple times but the same response. I need your support regarding that.

Hi and welcome to the community.

I haven't yet looked at the app blocks that you are using but it would be a good idea to test the comms with the HC-05 by using a Bluetooth serial terminal app. This is a useful tool to always have on hand when working with Bluetooth.

There are a few available on the Google store. The one by Kai Morich is popular.

I think you are using this example:

In Designer - BluetoothClient1 - DelimiterByte: 10

What is your Arduino code?

Here examples of Arduino + Bluetooth classic

I have given the link of the site, in the 3rd video the links are given for arduino code and app code blocks (.aia file). And as a beginner, I am unable to understand what you are trying to explain, can you please explain me one more?

Review the connections.

the connnections are correct, as the red light in bluetooth module is blinking, and if i tried to change the circuit the light stopped, and this means that the circuit is correct.

In code Arduino change


by (38400)

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You have built a project with several components. All of them must work for the project to work. Yours is not working so the methodical approach is to test each component and find the one that is not working.

Experience tells us that the commercial off-the-shelf components are probably okay and the mistakes occur in the custom made components like the app or sketch or the physical assembly.

By using a BT serial terminal app you take the app you have built out of the equation. Let's say the app sends the characters "F" "B" "L" and "R" when the buttons are pressed for "Forward" "Back" "Left" and "Right".

With BT serial terminal app you can connect the app to the HC-05 and send the text "F" "B" "L" or "R". If the Arduino robot reacts as you want it to, then the app is where the mistake lies. If it does not, then the problem is in the HC-05 or the sketch or the assembly. You plan your next move according to what you have learned. Methodically.

Does that help or am I confusing you more?

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I changed both at same time, it doesn't work.

I understood your meaning, but can u pls tell me clear cut what I need to do, and ya sry for latency.

Well, step one is to download and install the Bluetooth Serial app from Kai Morich. Can you do that?