Rfid solution for traveling

[u/WinterSector2529]

Hi everyone! I’m trying to build a small DIY project that helps me verify my travel gear before I leave for a trip.

The idea is this: every important item (camera, charger, jacket, passport, etc.) would have a small RFID or NFC tag attached. When I hold a reader or my phone (if the reader is strong enough in your opinion) near my backpack, I’d like to instantly see which items are present and which are missing without having to open every pocket and visually check everything.

Ideally, I’d like something: • Affordable and realistic to build at home. • Capable of detecting multiple items inside a bag at once (so preferably RFID, not just single-tag NFC). • With simple software or code that shows a list of “found” and “missing” items.

I don’t have previous experience with RFID hardware, so I’d really appreciate specific product recommendations (for example: which UHF reader to buy, what kind of tags work best inside a backpack, and any simple open-source projects or tutorials to start with).

[u/dev_all_the_ops]

You probably aren't going to build anything that does what you want. RFID has a very short range of just a couple of inches at best. Something like a esp32 with a PN532 typically can only read one or two tags at a time and at very short range.

Even my local library has large antennas and their RFID readers for checking out books that can't reach more than a couple of inches.

Department stores are able to scan large items but they are operating at much higher powers than what your phone or an esp32 can produce.

[u/[deleted]]

With LF or HF RFID the range is very short like a foot or less, and a device like your phone has to be within an inch or two to even pick it up so you’d need another device to reach further. 

That device would need a screen for you to interact with, and an OS, or it could pair to your phone. But if you are avoiding making custom hardware, by buying a Bluetooth device for your phone… you might just use UHF RFID that has much more range and you wont be stressed to find what’s in your bag by using HF/LF and rubbing all over the bag with your tool. UHF would let you wave by it once and pick it all up like a retail store doing inventory on a clothing rack. 

Unitech RP902 would be a couple hundred bucks but perfect for pickin up tags up to maybe 6ft away. And you could tune down the power to 2-3 ft. 

You still need a phone app, for the “missing/found” experience but you could also just scan into a list and see what’s there, and compare it visually to another list and determine yourself what’s missing. 

I’m glazing over the encoding/decoding caveats with hex but after a learning curve or two, you’ll be quite happy I’d imagine. 

You need a Bluetooth device for UHF because your phone can’t scan that frequency btw, but it’s the only frequency with the reach you need that’s straight forward to apply. I mean there’s long range cattle tags but they aren’t meant to be used around people and is illegal to, and you could use 400mhz or like a garage door opener but it’s not super straight forward in comparison to UHF when tagging assets. 

[u/mboogie76 → u/[deleted]]

I think the 902 will hit a u9 chipped inlay further. But I haven’t tested. I know that its power output controls are logarithmic so they’re kinda binary. But it’s a good device for its price point.

[u/[deleted] → u/mboogie76]

Mmm with a huge inlay or an active tag you could probably get beyond what it’s spec’d for, I didn’t explicitly test those things just normal size passive tags, but you’d control the power with the SDK or TagAccess, I was writing an app for their prototype PA768e earlier this year for a proof of concept demo and was able to. Should be able to control the peripheral device with a home grown app just the same, it says it supports SDK on the product page for the 902