Introduction: Bluetooth Door Opener/ Monitor

About: I am a Mechanical Engineer with lots of hobbies. I love electronics and have been working with electronics for decades. I love astronomy too, specially deep space.

OK! I have seen so many bluetooth open close videos, none of them allows you to check from inside of your house to see if your door is open or closed!

With this instructable, we will build one together using a free (or paid) app, a very nice and easy to

customize app called roboremo.,

I have been using it on my garage and have installed the app on more than one phone ( other family members) it works great!

I found it very useful and wanted to share with you. Hopefully, some of you can build it and make use of it.

If you have any question, please do not hesitate, ask, the community here is very helpful and I will be more than happy to help.

Step 1: The Components

Atmega 328: The MCU you use to build your Arduino compatible if you choose so!/ optional

Usbasp: An easy and fast to use programmer, also very cheap!/ optional

Arduino: Arduino board if you choose to buy one rather than building it.

Bluetooth: I used HC06

Headers: necessary if you choose to build your own Arduino./ optional

More headers:/ optional

Even more:/ optional

Crystal: for the oscillator circuit if you want to build your own Arduino./ optional

Capacitors: for the oscillator circuit if you want to build your own Arduino./ optional

Vero board: to put everything on!

Relay: To switch door on/off

Reed relay: To give feedback, is door open or closed!/ if you need feed back

Transistor: to drive the relay.

resistors 1 K ohm each



A small magnate. if you need feedback

The amazing roboremo app

And of course, solder, wires and other necessary tools.

The optional items needed if you want to build arduino compatible circuit from scratch.

Let’s get started!

Step 2: The Easy Way

The easy way is to buy an arduino or arduinocompatible device and load it with the code.

The picture shows an arduino compatible connected to the circuit with bluetooth and the rest of the circuit.

We connect the bluetooth as follows:

Vcc to Vcc


RX to TX

TX to RX

Make sure you upload the sketch before you connect the bluetooth.

Step 3: The Sketch

I have attached two files here, one is the arduino sketch and the other one is the app interface.

You upload the sketch to your arduino the way you want.

For the app, install the roboremoapp on your phone, then look for a folder called roboremo on your phone and copy the other file, (garage opener with led indicator) to that folder. once you open the app, you should see the required interface with the necessary code. You can modify it later the way you like.

Step 4: Wiring

If you elect to buy an arduino or arduino compatible, then you can follow the attached wiring diagram in the picture.

The black relay is a 5 volt relay driven by the transistor. It opens and closes the garage door.

The blue relay, is a reed relay which will be activated when the magnate approaches it. It does not need power source. There is a small but strong magnate attached to a screw, which I attached to the chain, added two nuts and then some super glue to keep it in place and to make sure it does not damage the chain. I got the magnate from an old tablet cover.

The reed relay and the magnate are optional, they allow you to check and see whether the door is open or close.

Once the magnate gets close to the reed relay, it will turn it on, the reed relay will bring d11 of the arduino to ground( zero). The arduino will send via blue tooth a code to the phone which will turn an led like picture on the app on and off.

Step 5: Ways to Build an Arduino Compatible

In the attached picture, (also found all over the internet), you see a diagram showing the connections required to build an arduino compatible . You then need to move everything to a vero board or just keep it this way!

You can program your new arduino, either by another arduino, or using USBaspprogrammer, which is faster and easier. The header(6 pins) you use to program your arduino has all the needed pins. This means, once your arduino is programmed, unplug the USBasp and plug your wires from the two relay circuits, which connect to D11, D13. And also Vcc and ground.

Step 6: Connect Your Bluetooth

Now, after programming your device, hook the bluetooth. make sure you change the pairing code to one of yours for security and also change the name if you like.

I have also changed the baud rate, you can keep the default one or change it, you, however, need to match what you have with the sketch.

If anyone needs more info about this, please ask, I will be more than happy to answer all your questions as soon as I can..

Step 7: In Action

The video here shows the app and the device in action.

I have been using it for a while now. I found it very useful and wanted to share with you. I installed the app on more than one phone ( family members) and they all able to open/close the garage from their phones. There is no need for expensive remotes.

I also, check from inside the house to see whether my garage is open or closed.

Thank you very much and hopefully, you will find it useful too.

If you have any questions, please let me know.