• Skip to main content
  • Skip to primary sidebar

Homemade Circuit Projects

Get free circuit help 24/7

Circuits for Beginners | Basic Circuits | LED Driver | Hobby Circuits | Transistor Circuits

New-Projects | Privacy Policy | About us | Contact | Disclaimer | Copyright

Home » Car and Motorcycle » Bluetooth Car Ignition Lock Circuit – Keyless Car Protection

Bluetooth Car Ignition Lock Circuit – Keyless Car Protection

Last Updated on December 19, 2020 by Swagatam 21 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.

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.  Cell Phone Call Alert Security Circuit
  • 2.  Build a Homemade GSM Car Security System
  • 3.  LED “Halogen” Lamp Circuit for Motorbike Headlamp
  • 4.  Free Energy Bicycle Generator Circuit
  • 5.  Simple E-Bike Circuit [Electric Bike]
  • 6.  Car Blown Brake Light Indicator Circuit to Detect Broken Bulb Filament Tail Light

About Swagatam

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials.
If you have any circuit related query, you may interact through comments, I'll be most happy to help!

Subscribe2


 

Reader Interactions

Comments

    Your Comments are too Valuable! But please see that they are related to the above article, and are not off-topic! Cancel reply

    Your email address will not be published. Required fields are marked *

  1. Arif Aleem Shamsi says

    Sir SWAGATAM,

    YOU ARE THE BEST AND BEST TEACHER, FRIEND AND GOOD MAN. GOD BLESS YOU

    Reply
    • Swagatam says

      My pleasure Arif, God bless you too!

      Reply
    • Mdu Magubane says

      Good Day Sir can i find something which is already built and try to install in my car?

      if so where and how much approximation?

      Reply
    • Swagatam says

      sorry MDU, I do not sell readymade kits, I can only advise regarding the circuit

      Reply
  2. swixxknight says

    can this be made to work with a specific code so that only your phone can open it

    Reply
    • Swag says

      it is already designed to operate with a specific frequency set inside the owner’s mobile…

      Reply
  3. Childs says

    Wow Sir.

    I respect you.

    I am gonna build this for my high risk car in a high risk car theft country.

    @Mdu Magubane, ziya buya la e mzansi lol.

    Reply
    • Swagatam says

      Glad you liked it!

      Reply
      • Childs says

        Awesome. Ever thought of applying these circuits to cut the fuel supply instead of focusing purely on the electric side?

        Big fan.

        Reply
        • Swagatam says

          Thanks childs, glad you liked it…

          Reply
      • Childs says

        Another question that I have Sir:
        I would like to be able to operate my car windows remotely (like modern cars do). I have front electric windows but that’s about it. Worse, to open the front passenger side window I have to lean over and kind of stretch to press the button. I would like to bring that button closer to home (lol, as in, be able to operate it comfortably from my driver seat if you know what I mean).

        Big fan.

        Reply
        • Swagatam says

          Hi Childs, it can be implemented using geared motor and limit switches. The motor can be configured with a DPDT relay and a 433MHz remote control receiver.

          Once this is done, the load (window glass mechanism) could be toggled up/down as desired.

          Reply
  4. Childs says

    Hi Mr Swag. In your discussion you talk about a 100K resistor going into pin 14 but on the diagram it is 10K. Is this a mistake or it is the arbitrary choice of the 100K/1000uF? If so can you please state the range of R to achieve the desired delay.
    Also, which relay would you recommend? I’m still starting out at this DIY thing.

    Reply
    • Swagatam says

      Hi childs, yes that’s right, the values are not critical, and can be selected by trial and error for the desired delay.

      The value of the resistor can be between 10K and 1M, capacitor can be from 1uF to 100uF

      Reply
  5. Childs says

    Hi Mr Swagatam. I ordered the parts for this circuit, however I see that I received the CNY17-3 instead of the 4N35 optocoupler. Is there any significan difference between the two optocouplers? Can the CNY17-3 do the job of the 4N35?

    Thanks for your help.

    Childs.

    Reply
    • Swagatam says

      Hi Childs, both will do, but I cannot see any opto-coupler in the above design

      Reply
      • Childs says

        No. The optocoupler is needed for the “modified bluetooth” circuit which the first link on this article.

        Reply
  6. Sarwana says

    Hello Mr.Swag , If read datasheet IC LM567 is supply with max 9v dc. In this circuit is supply 12v dc. it safe to supply IC LM567 with 12v dc ?

    Reply
    • Swagatam says

      Hello Sarwana, yes LM567 works with a maximum of 9V, I have corrected the diagram accordingly, please check it now

      Reply
  7. Mohamed Salem says

    dear sir.
    This is Mohamed , Senior Eng. for RL1 , as you know when you start the engine a high value of current has to pass through the RL1 . so what is the technical specs of RL1 , what is the max current can pass
    Regards
    Mohamed

    Reply
    • Swagatam says

      Hi Mohamed, you can use a 30 amp automobile type of relay, and for this you will have to replace the BC547 transistor with a 2N2222 transistor

      30 amp automotive relay 5 pin

      Reply

Primary Sidebar

Categories

  • 3-Phase Power (15)
  • 324 IC Circuits (19)
  • 4017 IC Circuits (53)
  • 4060 IC Circuits (25)
  • 555 IC Circuits (98)
  • 741 IC Circuits (19)
  • Amplifiers (58)
  • Arduino Engineering Projects (82)
  • Audio Projects (94)
  • Battery Chargers (82)
  • Car and Motorcycle (94)
  • Datasheets (46)
  • Decorative Lighting (Diwali, Christmas) (33)
  • DIY LED Projects (89)
  • Electronic Components (97)
  • Electronic Devices and Circuit Theory (35)
  • Electronics Tutorial (109)
  • Fish Aquarium (5)
  • Free Energy (35)
  • Fun Projects (11)
  • GSM Projects (9)
  • Health Related (18)
  • Heater Controllers (28)
  • Home Electrical Circuits (101)
  • How to Articles (20)
  • Incubator Related (6)
  • Industrial Electronics (28)
  • Infrared (IR) (40)
  • Inverter Circuits (98)
  • Laser Projects (12)
  • LM317/LM338 (21)
  • LM3915 IC (25)
  • Meters and Testers (63)
  • Mini Projects (171)
  • Motor Controller (66)
  • MPPT (7)
  • Oscillator Circuits (24)
  • PIR (Passive Infrared) (8)
  • Power Electronics (33)
  • Power Supply Circuits (74)
  • Radio Circuits (9)
  • Remote Control (47)
  • Security and Alarm (61)
  • Sensors and Detectors (116)
  • SG3525 IC (5)
  • Simple Circuits (74)
  • SMPS (29)
  • Solar Controllers (61)
  • Timer and Delay Relay (54)
  • TL494 IC (5)
  • Transformerless Power Supply (8)
  • Transmitter Circuits (40)
  • Ultrasonic Projects (14)
  • Water Level Controller (45)

Circuit Calculators

  • AWG to Millimeter Converter
  • Battery Back up Time Calculator
  • Capacitance Reactance Calculator
  • IC 555 Astable Calculator
  • IC 555 Monostable Calculator
  • Inductance Calculator
  • LC Resonance Calculator
  • LM317, LM338, LM396 Calculator
  • Ohm’s Law Calculator
  • Phase Angle Phase Shift Calculator
  • Power Factor (PF) Calculator
  • Reactance Calculator
  • Small Signal Transistor(BJT) and Diode Quick Datasheet
  • Transistor Astable Calculator
  • Transistor base Resistor Calculator
  • Voltage Divider Calculator
  • Wire Current Calculator
  • Zener Diode Calculator

Facebook
Twitter
YouTube
Instagram
My Facebook-Page
Quora

© 2022 · Swagatam Innovations

We use cookies on our website to give you the best experience.
Cookie settingsAccept All
Privacy & Cookies Policy

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Please visit the Privacy Policy Page for more info.
Necessary
Always Enabled
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Non-necessary
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
SAVE & ACCEPT