• Skip to main content
  • Skip to primary sidebar

Homemade Circuit Projects

Need circuit help? Post them in the comments! I've answered over 50,000!

Blog | Categories | About | Contact | Calculators-online
You are here: Home / Automobile Electronics / Bluetooth Car Ignition Lock Circuit – Keyless Car Protection
warning message: electricity is dangerous, proceed with caution
mainsremote

Bluetooth Car Ignition Lock Circuit – Keyless Car Protection

Last Updated on December 19, 2020 by Swagatam 25 Comments

This circuit will allow the user to lock his car ignition using his phone Bluetooth, meaning the ignition can be locked/unlocked only through a specific code from the user's cellphone Bluetooth.

Table of Contents
  • Overview
  •  How it Works
  • How to Test the Circuit

Overview

In one of my earlier posts I have already explained how to hack a Bluetooth headset and use it for any desired switching application via Bluetooth, here we apply the same concept for the proposed car ignition lock circuit using Bluetooth.In the project the cellphone becomes the Transmitter circuit, and the Bluetooth headset is used as the receiver.

If you do not wish to modify the Bluetooth headset into a receiver circuit, you an procure a readymade Bluetooth receiver unit also for the same

The idea is actually very simple, and may be understood by referring to the below given circuit:

 How it Works

As can be seen the circuit is configured around a specialized phase-locked-loop IC LM567 which is designed to generate a low logic whenever it detects a frequency at its pin#3 that may be matching exactly to the IC's internal oscillator frequency set by R1/C1.

For example, in the above diagram the internal oscillator frequency is set at 100kHz by appropriately selecting the values of the R1/C1 timing components, therefore it implies that the IC will produce a low logic whenever it detects a 100kHz across its pin#3 and ground. As long as this situation is not satisfied, pin#8 can be expected to be at a logic high level.

The C4 end and the negative wire of the circuit is supposed to be joined with the Bluetooth headset or any selected similar Bluetooth audio receiver gadget. This could be also easily done through an opto coupler for allowing a complete isolation between the two stages.

This takes care of the Bluetooth receiver stage circuit, now lets' move on and learn how your cellphone needs to be set up as the Bluetooth transmitter unit.

For this, you will need to download a frequency signal generator app in your android phone, or if your phone is not an android phone, you can record a 5 second clip of the selected frequency, let's say a 100kHz frequency clip for the above shown design.

How to Test the Circuit

Once this is done, it's time to test the proposed Bluetooth car ignition lock circuit, through the following steps:

1) Pair up the phone and the Bluetooth receiver gadget with Bluetooth.

2) Toggle the 100kHz frequency from your phone and simply send it to thee receiver gadget.

3) Wait for a few seconds, and ...."click".... you will find the relay operating, and unlocking or locking the car ignition, depending upon the initial situation of the relay.

The slight delay in operating the flip flop relay is initiated by the 100k/1000uF components at pin#14, and this is crucial in order to make the system foolproof, so that an intruder may not make an attempt to break the lock by randomly sending a Bluetooth frequency to the receiver gadget.

This delay must be confirmed with some trial and error, the indicated values of 100k and 1000uF is arbitrarily chosen, and may not be accurate.

The IC 4017 is rigged as a flip flop circuit which toggles the relay ON/OFF alternately in response to the LM567 signal.

The relay can be seen integrated in series with the ignition switch which implies that as long as this relay is switched OFF, the ignition key cannot be used for starting the vehicle, and it would work only once the relay is triggered.

If you have any further queries regarding this circuit you can ask them through your comments below

You'll also like:

  • 1.  Darkness Triggered Car Safety Park Light Circuit
  • 2.  DTMF based FM Remote Control Circuit
  • 3.  Sound Activated Remote Control Circuit
  • 4.  Multiple Appliances Remote Control Circuit
  • 5.  LED Tail Ring Light Circuit for your Car
  • 6.  How to Make a Remote Control Circuit from a Remote Bell

Filed Under: Automobile Electronics, Remote Control Circuits Tagged With: Bluetooth, Ignition, Keyless, Lock, Protection

About Swagatam

I am an electronics engineer and doing practical hands-on work from more than 15 years now. Building real circuits, testing them and also making PCB layouts by myself. I really love doing all these things like inventing something new, designing electronics and also helping other people like hobby guys who want to make their own cool circuits at home.

And that is the main reason why I started this website homemade-circuits.com, to share different types of circuit ideas..

If you are having any kind of doubt or question related to circuits then just write down your question in the comment box below, I am like always checking, so I guarantee I will reply you for sure!

Previous Post: « “WELCOME” LED Display Circuit
Next Post: Arduino based DC Voltmeter Circuit – Construction Details and Testing »
Subscribe
Notify of
guest
guest
25 Comments
Inline Feedbacks
View all comments

Primary Sidebar

circuit simulator image

Subscribe to get New Circuits in your Email

Categories

  • Arduino Projects (90)
  • Audio and Amplifier Projects (132)
  • Automation Projects (17)
  • Automobile Electronics (101)
  • Battery Charger Circuits (84)
  • Datasheets and Components (105)
  • Electronics Theory (140)
  • Free Energy (38)
  • Games and Sports Projects (11)
  • Grid and 3-Phase (19)
  • Health related Projects (25)
  • Home Electrical Circuits (12)
  • Indicator Circuits (15)
  • Inverter Circuits (89)
  • Lamps and Lights (142)
  • Meters and Testers (71)
  • Mini Projects (46)
  • Motor Controller (64)
  • Oscillator Circuits (28)
  • Pets and Pests (15)
  • Power Supply Circuits (89)
  • Remote Control Circuits (50)
  • Security and Alarm (64)
  • Sensors and Detectors (103)
  • SMPS and Converters (31)
  • Solar Controller Circuits (60)
  • Temperature Controllers (42)
  • Timer and Delay Relay (49)
  • Transmitter Circuits (29)
  • Voltage Control and Protection (38)
  • Water Controller (36)

Other Links

  • Privacy Policy
  • Cookie Policy
  • Disclaimer
  • Copyright
  • Videos
  • Sitemap

People also Search

555 Circuits | 741 Circuits | LM324 Circuits | LM338 Circuits | 4017 Circuits | Ultrasonic Projects | SMPS Projects | Christmas Projects | MOSFETs | Radio Circuits | Laser Circuits | PIR Projects |

Social Profiles

  • Twitter
  • YouTube
  • Instagram
  • Pinterest
  • My Facebook-Page
  • Quora
  • Stack Exchange
  • Linkedin
  • Recent Comments

    • Swagatam on Simple Buck Converter Circuits using Transistors
    • David on Simple Buck Converter Circuits using Transistors
    • Swagatam on Clap Switch Circuits with Relay ON/OFF: [Tested]
    • Mark on Clap Switch Circuits with Relay ON/OFF: [Tested]
    • Swagatam on Boost Converter Calculator

    © 2025 · Swagatam Innovations