Key Finder

justminick · Nov 28, 2012

Please Advise Me Key Finder

Hello All,

I enjoy trying to make custom made, from scratch things, and I'm looking to try to make the following (Please keep in mind I'm a newbie and I'm going come off sounding really uneducated on this) :

A wireless key finder that has Bluetooth (or something better? RFID? I don't know - please advise) capabilities so that I can sync it to my iPhone. Ideally, it'll be like any other key finder out there - just made by me. I want to though, make it beep and possibly (not necessarily) flash a red light. It'll just be a key chain that will go on a ring with my keys. I can build the holding unit myself (I make models as an architectural designer all the time). This first round will probably be a test run anyways.

Basically, I'm looking for advice on which products I should check out. I was going to just get a Bluetooth sticker and then detect it's presence within my vicinity, but if I am going to do this, I want to do it right.

Thank you,
Nicki

GreenGiant · Nov 28, 2012

I would say start with some bluetooth chips/devices and work out how the detection and send/receive goes, you are going to need to make it so that when the phone syncs with the device, it receives the handshake which starts the beeping that you want.

I personally would start with one of my arduino's and a bluetooth shield, then try to work out the signal that is output through the shield when the handshake with the phone is successful then try to engineer a general circuit that will beep once that signal happens

I hope this gets you started in the right direction at least

donkey · Nov 28, 2012

ok a few things to consider on this. first and foremost is power. check the power consumption of a bluetooth device.on bluetooth 4.0 they got a new feature called BLE but I cannot find a cheap unit that uses this, so your keychain may have to be charged daily(or more often).
second PROGRAMMING. this is my biggest hurdle for my projects.and you have double the programming. you have to program the arduino to do what you need it to and then program the Iphone to do what it needs.
the rest is pretty easy.
personally though I would go 2 arduino modules (one to hook up to your iphone one for the keychain) then use NRF24L01 modules that seem to be super low on the energy requirements. the problem then is that there is 3 times the programming and an extra bit.

Key Finder

justminick

GreenGiant

donkey

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