Anti-theft alarm for motorbike

I came across this project on instructables on the safety system for motorbikes.

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 us 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.

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 plug is ideal)
Some electrical tools and a little electronics knowledge.

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

Then wire two very fine wires to the button contacts under the digit (3) it doesn't 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  the 2 wires are attached  reassemble the phone and check if 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 this is done short the connector again to check the alarm phone will call the mobile.

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.

http://www.kpsec.freeuk.com/555timer.htm#monostable

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.

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

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

then 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 movement is detected. They can be connected directly to the circuit with out a relay but using a relay will give more options and a more positive switch.

You can have a many switches as you want.

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  the bike is onthe phone gets charged.

fit a bike immobiliser on the bike

http://www.instructables.com/id/A_Simple_Car_Motorbike_automatic_Immobilizer/

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

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

after  everything is installed on the motorbike.
and wire everthing up.

It is 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

Courtesy:instructables,simon72post