Smart Lock Using Bolt-IoT

Device Image

In this world where technology is taking over the mankind and we are getting smart and easy solutions for each of our daily faced problems, starting from the electric brush ending with voice controlled room lights. Then why not to make something COOL and CHEAP to help us deal with opening and closing our house door more securely and conveniently.
Excited? Lets get into it….


The main problem that I am trying to solve is to make a cheap and secure way to open our house door by just tapping in our smart phone that can run 24*7.

Things used in this project

Hardware components:-

  1. Bolt-IoT
  2. Arduino pro mini
  3. Servo
  4. 5V Adapter
  5. Nylon thread

Software, Apps and online services:-

  1. Bolt-Cloud
  2. IBM-Cloud
  3. Node-Red
  4. Google-Sheet
  5. Mit-APP- Inventor
  6. Arduino IDE

Hardware setup

While making this project I had tried to keep the hardware as simple and as cheap as possible so that the parts if gets damaged can easily be replaced without any hassle.

The Schematic diagram is as follow:-

Just do this easy connection with the bolt module and fix this beside the door lock just as the image shown along with the adapter and we are good to go with the software part. We can make the system look more good and compact by hot-gluing the parts together and cutting the extra wires.


Software Programming & Cloud Setup


Setting up the IBM Cloud to host Node-Red so that the backend and logical operation can be done over the cloud without any interruption.

Step 1:- First create an IBM Cloud account from

Step 2:- Search for NODE-RED in the search bar. Then select the NODE-RED App.

Step 3:- Follow the steps necessary to deploy the service as mentioned.

Step 4:- This screen will open after the service is successfully installed. Then click on “Your app link”.

Step 5:- This screen of Node-Red will appear, then click on the “Go to your Node-Red flow editor”

Step 6:- This Node-Red Flow editor will appear then click on the IMPORT and select the noderedflow.json from the Github repo.

Step 7:- Your flow will look like this, then click on DEPLOY in the upper right corner of the editor.

Step 8:- Copy the link of this node-red flow (This will trigger the system) to put in the MIT-APP-INVENTOR.

NOTE:- Change the BOLT API request URL and also the user phone number.


Setting up the Bolt Cloud so that it can receive the user input through IBM Cloud and operate the Servo/Actuator to open the door using Arduino.

Step 1:- Add your Bolt-Module in the After that Enable the API Key in the API section.

Step 2:- Select the right port and device and then click on the “build api request” and add the urls to the Node-red Flow editor.

Step 3:- If by any chance we hit the maximum API request threshold then we can follow the below steps.

Step 4:- Click on the device section, then beside the correct device choose the “View this device” option.

Step 5:- This pre made page will appear integrated with the API request of the DIGITAL PIN 0. We can manually operate the lock by clicking the buttons.

Google Sheet

Step 1:- First Create a google form and copy the pre-filled link of the two parameters.

Step 2:- Paste the link in the Node-Red Flow editor in the “google sheet link”.

This type of entry will be stored inside the google sheet after triggering the system to open the door.


Step 1:- Go to then click on the create app option in upper left position. Then create/login with your account.

Step 2:- This type of interface will open, click on the Import project .aia from computer. Then choose Door.aia from the Github Repo.

Step 3:- Now all the Design will appear, put the Node-Red links in the mentioned Block and click on the build apk.

Step 4:- Now install that apk in your ANDROID smartphone and you will be good to go.


Step 1:- Copy or download door.ino from the Github Repo.

if (buttonState == 1) {
servo.write(0);//CLOSE lock
servo.write(180);//OPEN lock

Step 2:- Change the CLOSE and OPEN lock position as your own lock.

Step 3:- Upload it to the Arduino Pro mini.

Coding,APK, .aia, Flow

Each and every coding of the project along with the apk file that i had made using mit app inventory, is given in the github link bellow download the project and give it a try to make it by your own, it is super adventurous and fun.


After completing with the project i had gain more confidence about the IoT and app making field and knowledge about those part want to thank bolt IoT for giving me the opportunity to learn and discover the projects by my own, it’s been a great journey.

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