plz help me build bike finder

[ravimenon]

please help to build a circuit which i'll explain below

In cars when we have automated locking system which buzzes and makes the light glow with a very small circuit in the key chain

i actually want something similar to my bike, i tried using IR emitter but the range is very small.

can u suggest me some component other than IR emitter so that it actually works in bigger situations like parking lots

thanq in advance

 

[Reloadron]

Circuits like what you want are easier bought as kits than built due to the RF requirments. I believe something like this is what you want. That is just an example as you would not need a four channel key fob relay card. I have seen one and two channel versions for less money. I have used that particular version at work in a few safety applications and they work quite well at ranges of 100 meters.

Ron

 

[ravimenon]

Yeah but I actually want to build them...

Yeah but I actually want to build them...

do u know what type of transmitter and receivers are used in the car locking system..?

 

[Reloadron]

Yeah but I actually want to build them...

do u know what type of transmitter and receivers are used in the car locking system..?

Well if you want to physically build one then I suggest you start reading here. That should give you an overview of how systems like this work. You may want to pay close attention to this part:

An RKE system consists of an RF transmitter in the keyfob (or key) that sends a short burst of digital data to a
receiver in the vehicle, where it is decoded and made to open or close the vehicle doors or the trunk via receivercontrolled
actuators. The wireless carrier frequency, is currently 315MHz in the US/Japan and 433.92MHz (ISM
band) in Europe. In Japan the modulation is frequency-shift keying (FSK), but in most other parts of the world,
amplitude-shift keying, or ASK is used. The carrier is amplitude modulated between two levels: To save power,
the lower level is usually near zero, producing complete on-off keying (OOK).

Especially the frequencies based on your location. Good luck designing board layout for the frequencies involved. The link will give you an overview of how things work.

Ron

 

[crutschow]

If you have to ask how to build RF circuits, then likely they are beyond your expertise and available test equipment.

 

[ThermalRunaway]

If you have to ask how to build RF circuits, then likely they are beyond your expertise and available test equipment.

Ummmm.... yeah I can see where you're going with that statement, but to be honest you could almost apply that same attitude to anything. For example, if I came on to the board and started asking for help in how to calculate Ohm's law you could just as well reply "if you have to ask then it's beyong your expertise". And you would be correct of course, but then that would be the whole point of my asking.

It's not quite as simple as that with RF design of course because there's no easy answer to the question "how do I design RF circuits". But there's only one way to learn, and that's to start having a go and learning by failed attempts. A good grounding in general electronics is a pre-requisite though.

The test equipment issue is totally valid -100% agree with you there.

Brian

 

[crutschow]

Well, I was guessing I know, but I assumed from the nature of the inquiry that the op had little experience in building circuits, and if so, RF is not the place to start.

 

[ThermalRunaway]

Well, I was guessing I know, but I assumed from the nature of the inquiry that the op had little experience in building circuits, and if so, RF is not the place to start.

Yep agreed. I do see where you were going with your statement.

 

[ThermalRunaway]

With regard to the original post, here are my suggestions:

Take a look at the HT12 series of encoders/decoders from Holtek. These are ideally suited for your particular application and all you need to do is add a suitable RF transmitter module (or IR if you want but you already said IR had insufficient range) and receiver module at the other end.

Here's some links:

https://www.electro-tech-online.com/custompdfs/2011/06/57851.pdf
https://www.electro-tech-online.com/custompdfs/2011/06/57850.pdf

Have a read of those and then you should have a better idea of how to go about designing your circuit. If you have any further questions post them here.

Brian.