Item locator

This is what was assign as our thesis, our plan was to use RFID for our project but our software advisor told us to try searching for other options such as bluetooth, IR or wifi..

i would like to ask what should i use from the three and if i still need them even with arduino, we can't use smartphone or laptop as the locator

Bluetooth, IR and wifi can be technologies for transmitting a data stream over a distance.
RFID is mainly a technology designed for identifying an object.
What are you trying to do ?

well, actually a bracelet that would blink if you're meters away from the item

That does sound a bit like RFID. If your object cannot be identified (because it is out of range of the reader in the ‘bracelet’), the ‘bracelet’ gives a signal.
Some RFID technologies have a range of 100’s of meters.

But it would work with the other technologies. The ‘item’ emits a signal (over Bluetooth, IR or wifi) and the bracelet attempts to receive that signal, giving a warning if the item is out of range.

I'm wondering if your thesis supervisor had a wicked sense of humour. :grinning:

With various technologies, you can determine whether two items are "in range" or "out of range".

What they can not in general, is to specify such a range; to reliably distinguish between 10 cm and 10 metres, as firstly, the propagation of radio waves depends on shadowing, absorption, reflection, focussing and such.

Secondly, the "flight time" of radio signals over such distances - such as 10 metres - is in the order of single-digit nanoseconds, so "radar" technologies to measure this require very specialised microwave circuitry.

To be able to do so is a frequently asked question, and such commercial systems as are available to perform this task are very sophisticated - and expensive.

We wish you luck.

I'd like to ask which one is better to use for arduino since we're still beginners in the field of arduino and would like to know what arduino should we use as we're are currently planning to create a working prototype.

If one is chosen I would like to ask if there are also some source code examples if possible.

sorry of the inconvinience

konichiwa08:
I'd like to ask which one is better to use for arduino since we're still beginners in the field of arduino and would like to know what arduino should we use as we're are currently planning to create a working prototype.

I'm going to gently suggest that your advisor is suggesting you do some sort of trade study looking at the relative merits of the various technologies. Previous posters have given you a start at that task. I'd suggest also that "better to use for arduino" isn't really a strong criteria although any of the techniques mentioned can be implemented with standard Arduino and peripherals.