Introduction: Mobile Phone Alarm for a Motorbike, Car or Anything You Want

Picture of Mobile Phone Alarm for a Motorbike, Car or Anything You Want

I got fed up with normal alarms making a lot of noise, and no one taking any notice of them any more.

Also not knowing if anyone had messed with my bike because I was to far away to hear the alarm.

So I decided to make this alarm using an old mobile phone and a simple timer circuit.

The basic principle is if the motorbike is moved it will trigger a timer circuit,
which will send a 3 second pulse to a mobile phone, which will phone me to let me know that something has moved my bike.

This project is not just for a motorbike, It could also be altered you warn you about anything you want.
ie house, shed, car.

Step 1: Items Needed

1 old phone with speed dial.
1 mobile phone car charger.
1 555 timer chip
2 relays 12 volt
some tilt vibration switches.
some resistors and capacitors
some wire
a small plug and socket. (a phono plugs is ideal)
Some electrical tools and a little electronics knowledge.

Step 2: Modifiying the Phone

Picture of Modifiying the Phone

To start with I got hold of an old nokia mobile phone.
I removed the case and carefully removed the front panel that sits underneath the keypad. this was held in place by torx screws.

Then I wired two very fine wires to the button contacts under the digit (3) it doesnt mater to much which button you use but I used this number because its not used for my phone number and because it was close to the side of the phone so it was easier to bring the wires out.

When I had attached the 2 wires I then reassembled the phone and checked it worked ok. by shorting together the connector with a piece of wire. to make sure the phone will activate the digit 3.

Next you will have to go in to the phone menus and set up a speed dial on button 3 for your own mobile phone.

After I had done this I shorted the connector again to check the alarm phone will call my mobile.

Step 3: Timer Circuit

Picture of Timer Circuit

Next job was to make a simple 555 monostable timer circuit. You can find lots of useful information on building 555 timer circuits here.

the relay coil is wired between the 555 timer IC output and 0 volts.
you will need a diode across the relay to protect the timer chip.

The reason for the 555 timer circuit is to make sure when one of the sensors on the bike is triggered it will cause a 3 second signal that will trigger the phone.

It has to be 3 seconds other wise the phone will not dial the number.

I used a 13K resistor and a 220uF capacitor for R1 and C1 this gave me a 3.14 second pulse.
You may have to change the values slightly depending on the phone you use.

Step 4: Connecting It All Up

Picture of Connecting It All Up

I then wired 2 wires from the relay contacts to a socket, and pluged the connector from the phone in to the socket wired to the relay contacts.

I was then able to check that the timer circuit will trigger the phone correctly.

The next job was to connect up all the sensors to the timer circuit.

This was just a matter of connecting some tilt switches and vibration switches in parallel to a relay. Which will trigger the timer circuit when movment is detected. They can be connected directly to the circuit with out a relay but I found using a relay gave me more options and a more positive switch.

You can have a many switches as you want.

In the past I have also wired my garage door in to the circuit.

Step 5: Fitting to the Motorbike

Picture of Fitting to the Motorbike

Then next job was to fit the timer circuit and relays in to a plastic box. And fit the parts on to my motor bike. And connect up the phone charger to the bikes ignition so when I am riding the bike the phone gets charged.

I had already fitted a bike immobiliser on the bike

so when the ignition is switched off the alarm is armed and when I reset the immobiliser, the power to the sensor / trigger relay is switch off. which will disable the alarm circuit.

I just wired the sensor / trigger relays 12v supply, from the immobilizer relay so when the immobilizers led is lit the alarm sensor relay in powered.

Step 6: Final Testing

Picture of Final Testing

after I had installed everything on the motorbike.
and wired everthing up.

It was just a simple job of trying to move the bike with the ignition off and seeing if the phone dialed my mobile.

if not you may have to make some fine adjustments to the movment and vibration switches.

you will be able to tell if they are activating the relay because you will hear it clicking on and off.

If the relay is being activated but the phone is not dialing you will have to check your wiring on the timer circuit.

and that is about it.

Step 7: Future Upgrades

Some future plans I have are.

modifiying the phone so that if anyone sets the alarm off. I can phone the bike back and set off an audiable alarm or siren.

Also to completly disable the bike to stop them being able to start it.

or even instead of a audiable alarm / siren I could have the bike broadcast a message like " please move away from this vehicle"


pdoubled (author)2017-08-12

could you broadcast a signal on an unused part of the FM band and have your phone tuned into the frequency for the signal of movment to avoid using a cell phone with a Sim card ?

NakshN (author)2016-12-20

Nice One!

Wingnutz420 (author)2016-08-09

I'm having a lot of problems with people getting in my car so if you could send me a detailed version that I could hook into my car schematic to wire into the car wiring like when someone opens the car door I would really appreciate it thanks you can send it to

JicnorB (author)2016-06-29

Pls send me a schematic diagram

BiswajitN4 (author)2016-06-07

Dear Sir,

Wow! This is nice project. i need to make this project.but i need the circuit diagram,

Kindly put or send me the circuit diagram by email.



Mehmoodl (author)2015-08-11

how to start a motorbike with mobile

gordon.king.315 (author)2015-08-09

Why can't you use the accelerometer incorporated into Android phones as a motion detector?

OvieT (author)2015-05-20

This is a very nice project...I'm doing research on a similar one like this, only this time, it's a CCTV camera that's able to transmit video and picture field to a phone and the phone being able to request for video or picture fields...I don't really know where to start though, but would really appreciate some pointers...

logan.c.thompson (author)2015-04-20

Pretty sure you're on to something here. Try getting a patent for the idea of having an alarm connected to the cellular network to be able to communicate with your phone.

Like if the alarm goes off you can call the bike back and it's automatically on speaker. Or if you used a newer phone to could send it's geo-location to you if it senses it was being moved..

lugiae (author)2015-03-26

hi sir, can you show me your timer circuit? im not very understand.. i want to create this device too..but i dont understand how the speed dial button is trigger for 3 second..

pramodparmale (author)lugiae2015-03-31

Sir show me timer cicuit

harjit.singh.9256 (author)2015-01-24

hi sir what is your context no. I want your divice

jleo1 (author)2013-11-28

How about a upgrade.
buy the cheapest android phone you can find that has a camera.
open the phone and desolder the camera and attach it to a bit of telephone lead. mount the phone into the plastic box with the camera lead and power lead coming out. glue the power lead in place. cover any holes on the box with hot glue and the back of the camera. install the speed dial hack as above. finally install camera remote app and a good find my phone type app. cable tie the box some where and hide the camera in the dash wire the power cord to the battery.
put in a very low cost price plan like giff gaff. £5 every 3 months and its free giffgaff to giffgaff so your phone wont need credit to call you. if you get a call from your vehicle remote view the camera to get video or photos if it is being stolen to show who it is when it stops moving text the find my phone app to show you where it is then either call the police or

itminister (author)jleo12014-09-18

If the thief disconnects the battery main wires before stealing, some rechargeable cells may be attached in parallel to battery somewhere hidden.

bgoodwin12 (author)2014-09-01

dat FZR tho...

jun_n_venie (author)2014-08-07

nice bike, love the color combo!!!

whady (author)2014-05-25

can i use a laser and a photoresistor? and when the laser is interrupted the cell phone sends a message or call to the owner of the car?

carlitos (author)2014-02-03

Nice project. To avoid periodic costs associated with an active phone/prepaid phones, the solution is to not use a phone! Of course this is limiting as you need to have a receiver within range of a transmitter. I've built such devices using RF. You can have a handheld receiver with you that produces an audible alarm. You can also receive a text as well but you need a receiver (within range of the transmitter), connected to a computer with internet. With a distinct signal for movement, you receive one text (or alarm) for movement and another for out of range.

pbituin (author)2013-09-20

Hello Sir, I am just wondering. My team is planning to have this mobile alert with our motion alarm. Is it possible for it? I mean, when the PIR will detect a motion or change in temperature, will it not just trigger the buzzer to sound, will it also trigger the phone to call a certain number?

pjp72 (author)2013-09-05

Now I love the project it's awesome and very useful, the one thing that I didn't see mentioned (I apologize if I missed it) is that you'd have to have the phone on the bike/vehicle on a company plan to be able to send signal via speed dial correct? This would mean paying for 2 cell phone plan's so that you can receive the emergency on your phone you carry everyday as well as one on the phone sending the call, I'm just posting so I know if this is correct or not am I missing something here that you don't have to have the permanently mounted security phone on a plan so it can call out etc.?

rweatherall (author)2013-08-28

I think this is just brilliant! Glad to have come by such an awesome idea which I'll use in the future

mohnggohloidz (author)2012-08-28

what are the volts of 13k resistor and 220uf? pls give thanks

ninja_joey (author)2012-05-08

This is awesome! I have an alarm in my bike already but it doesn't even chirp from like 100 feet away,despite it's claim if 1/4 mile,or something like that,range.

Some of this stuff seems a little hard for me since I am beginning to understand schematics and know how to wire it all up,but I'm sure my electronics instructor and robotics club mates can lend me a hand...

I too would like to do this instructable and wire it to me already existing alarm for its siren.It has a nice screech to it.

Any further help would be nice.

salikkuraishy (author)2012-04-26

thats really nice idea :) bt i would want help !!! i am living in India and there lot of thieves !!! bt wot dey do is they steal bloody petrol nd i really want to catch a person red handed !!!! so any idea connecting this with petrol pipe ??? i even had petrol lock bt they tampered it :/ nd i cant get any evidence my bike is yamaha FZ16 please help me out and thanks :)

arifpulikoor (author)2012-04-20

pls, add this projects complete diagrum

saleelsayeed (author)2012-04-04

pls suggest any optical sensors that can sense any attempt of theft

shazaad mohamed (author)2012-03-22

can you please give full report of ur project and i need clear circuit diagram of this

silverwindro (author)2012-02-21

Hi, i`m having a noob question, how do you enable or disable the alarm?
If i put it in a car, how do i disable it when i open the door?

nfarrow (author)2012-01-19

Would be cool to use this same technology without a cell phone, maybe use a walkie talkie since they can transmit now over 6 miles.

zerdent (author)2011-12-29

man you guys stole my idea lol,, all i was gonna do is use an old i mean really old with quick dialing capabilities and use couple transistors, a mercury switch to turn on and dial your phone number (your new one) and to alert you when they try to straightened and move your bike,,,, simple but effective

simon72post (author)2009-09-09

Hi dev6862 the easiest way to add a phone would probably conect a timer circuit to the siren. so when the siren goes off it will trigger the phone the only dificalty you will have is if the alarm beeps when you arm or disarm it. it will trigger the phone unless. you make a time delay.

malkandi (author)simon72post2011-12-07

Can you please make me a devise which should connect to a alarm in my room and when ever my vehicle is moved away by a certain distance the radio connection gets disconnected and the alarm starts. My car was stolen just a few months back. Thank you

nissans (author)2011-08-07

If the bike is put in a truck, as so many are, the alarm should be silent and device hidden.
the phone should notify you so you can log in to track it via the gps function,
alert police for rapid recovery before device is discovered or bike is striped and dumped.

bumsugger (author)2011-08-05

Hi there,
I did originally see and like this Instructable some time ago and I noticed that you stated that you had a "future plan" to update the alarm by including a facility whereby you would be able to call the call the bike and trigger the alarm by remote control,for instance if you were in sight of the bike but were some way off,and it was suffering someone interference of some sort.Did you ever get to round to incorporating this feature?

tokymaru (author)2011-06-26

how would go about using the phone with/instead of the siren from the original alarm, using the original sensors?

jimmytvf (author)2011-06-11

i've thinking for a while of making a "mobile alarm" with an arduino, but this is way easier. consider the possibility of adding a switch to disconnect the alarm system when you're on the road. my idea is, instead of calling you, call directly to the police and also trigger one of those voice memos saying something line "this is a call from a motorbike. is being stolen right now, please backtrack the mobile signal to get to it. please don't hang up to track the signal. thanks" and will catch the thieves on the run.

tokymaru (author)jimmytvf2011-06-26

good idea, but more often than not (at least with cars) the alarm is set off by it moving alot; ie something hitting it, or it being broken into to steal something, not necessarily it being stolen. alot of times, especially if its a sensitive sensor, the police don't really need to be contacted unless a report needs to be filed.

amrit0003 (author)2011-04-02

i had made this project before you,but i implemented it in security system ,and used microcontrollers

ardvark (author)2011-02-13

love the project I had a similar idea a few years ago but never got round to working out how to do it why not make use of the mobile phones camera and gps sim card location that way you would have a state of the art alarm and the evidence you need to parse on to the authoritarians.

DoubleTrouble (author)2011-01-06

Good project, I'm not sure if anyone mentioned this, but couldn't you just wire the phone into the battery to keep it charged. Maybe with a trickle charger or a timed charger as not to drain the battery?

Emberblade (author)2010-05-02

i like your  ideas, however, it might be more prudent just to make the audible alarm go off as the tilt switches activate.

also, i know my bike has a lock on the forks to keep it steered in one direction, which have been fairly helpful in the past....

another thing, if you were to put a switch on the leads to the battery, after the alarm systems of  course, then you could make the immoblizer to kill the power to everything except for the alarm.

Great Instructable!  cheers ,   E

WolfTohsaka (author)Emberblade2010-12-26

Hello Emberblade,

You're lucky to have the park position sufficient to prevent steal from your region of the globe !

here motorcycle theft is more like :
- check if motorcycle is valuable
- check if it is attached to a pole/smth
- cut the rim if attached by rim (motorcycle rims are more fragile than SRA/FFMC rated anti-theft devices)
- lift the motorcycle
- drop into truck
- sell motorcycle
- GOTO 10

well, you get the drift.

So, in that case, audible alarm as you say can be useful. And for the immobilizer, never cut the battery. on recent bikes like mine, you will cut everything electronic and the bike will put itself to default and you will lose the setup (daily km, hour, ...)

the best thing on carb bikes is to cut spark ignitor. because if you only cut starter device, you can still push the bike in 2nd gear.
on injected bikes, just cut the crankshaft position sensor. it will make the bike shut down properly / prevent it from starting.



Emberblade (author)WolfTohsaka2011-01-06

If the fork locks are not you thing, a rear disc brake lock could prevent theft, then of course, the old standby for city living, chaining you bike to a pole.

That's true about the electronics bit, losing you settings and all, I never considered that, my bike is from the 80s, a kz 650, so I don't have any computers on it. And yes, I agree that cutting off the spark ignitor or the crank sensor would be the best idea for people with a computerized bike. Where I am, bikes are stolen fairly often, in fact once I saw my friends bike up for auction on eBay only a week or so after it was stolen from him! Crazy world we live in, but that's the beauty of this instructable! Now i can have a contingency plan for when someone tries to ride off on my bike. Hopefully, I won't need to use this, as my current system of chaining it to a nearby pole works brilliantly, but if I had to park it somewhere I wasn't familiar, I would feel good with this added protection



WolfTohsaka (author)Emberblade2011-01-06


Actually, crank sensor is betten than spark ignitor, because the ECU shuts down properly, whereas spark cut, it still puts gasoline.

On a 650KZ, it is the only solution, only thing electronic being the blinkers :p

Chaining to a pole is one of the best solutions IMHO.

I do use a disk lock device with embeeded alarm, and a U-type lock when travelling to protect my bike (V-Strom). alarm disk locks can be found on ebay for something like 20 bucks.

I use it not to prevent theft, but more to prevent bike-fiddling,

eschneck (author)Emberblade2010-12-26

Just a word of advice - the fork locks are worthless. My 4 day old Suzuki GSR-R 750 was stolen because I left it locked with just fork locks. All it takes is 1 or 2 people to lift the front end (or the entire bike) and it's gone. Live and learn! :)

3366carlos (author)2010-12-30


Cosmic Cat (author)2010-07-01

This is a great instructable! I have one observation though. The old phone that you use to dial your primary phone has to be currently activated right? In other words, it has to be in service or it won't be able to dial out and make calls. I didn't think you could use any old phone without it being active. Could you clear this up? Thanks

jsgraham (author)Cosmic Cat2010-12-24

@Cosmic Cat... You would definitely have to have the phone in the circuit active. Basic cell phones are a dime a dozen nowadays. In my experience, most of the "basic" cell phones released in the past couple of years, can be activated on a prepaid plan through local "mom & pop" resellers. "Basic" as in just simple texting and calling options. I had an old AllTel phone that I activated through a reseller on a simple prepaid plan. Tracfones, Net-10 or other prepaid phone will fit the bill. If you're only going to be using it for this purpose, the cheapest plan possible should do the trick.

@ simon72post... This a great instructable. I've been looking for an affordable alarm for my bike. Thanks for putting this together.

srilyk (author)jsgraham2010-12-29

Also, a lot of pay-as-you-go plans have no expiration date on the minutes, and they only charge on the days you use (at least at&t go phones).

Kasm279 (author)jsgraham2010-12-26

If you use a tracfone, make sure you look up stuff on the battery life first! My Motorola-but-not-Motorola w376g gets two days ON IDLE....

About This Instructable




More by simon72post:Arduino powered bluetooth remote relay switchHow to back up your usb stick or camera to your android phoneHow to back up memory cards without a computer
Add instructable to: