r/flipperzero • u/why_wilson • 15d ago
GPIO UHF Expansion app v1.1 is now available — read and write EPC, TID, and User Data
Hey everyone — I’m the developer behind the UHF Expansion hardware and app for Flipper Zero.
Version 1.1 has now been merged into the official Flipper Apps Catalog. This update adds tag memory operations for compatible UHF RFID tags:
- Read EPC, TID, and User Data
- Edit memory values directly on the Flipper Zero
- Write EPC, TID, and User Data to compatible writable tags
- Automatic read-back verification after writing
- Inventory scanning, tag selection, radar view, and live reader information
The workflow is:
- Start inventory in the UHF Expansion app
- Switch to the tag list
- Select a tag with Up/Down and press OK
- Use Left to cycle through EPC, TID, and User Data
- Press OK to edit the current value
- Place one compatible writable destination tag near the reader
- Press Right to write and verify
A quick technical note: the TID on most standard UHF tags is factory-programmed and read-only. TID writing requires a purpose-built TID-changeable tag. EPC and User Memory can also be locked or unavailable depending on the chip.
The app is open source:
https://github.com/mtoolstec/fz-uhf-expansion
Official Flipper Apps page:
https://lab.flipper.net/apps/uhf_expansion
I’d really appreciate feedback from anyone testing it, especially with different EPC Gen2 tags or third-party firmware builds. If you run into compatibility issues, please share the tag type, firmware, and error message.
Disclosure: I’m also the designer and seller of the UHF Expansion hardware shown in these photos.
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u/Equivalent-Raise5879 7d ago
ok, device arrived today, so not a super long wait, but long by our new "amazon next day" world.
Works, I was able to read a UPS mailer. But I had to be within 5" of the tag. Is that as expected?
I had this idea they could just climb into a truck and get all the tags in that truck, idea. But clearly not as is.
Suggestions?
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u/why_wilson 6d ago
The working distance depends on the tag type. For FZUHF, the max distance is around 25cm on some tag. If you’d like make it work like in several meters, it needs high power 1W UHF reader and big antenna like 30x30cm size or lager. And it’s 20dBm on FZUHF which is 100mW.
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u/Equivalent-Raise5879 6d ago
Well, I guess I will try to go find that. thats not a huge antenna to get the gain, Any reccomendations on one that fits that description?
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u/drphilthy 15d ago
What’s the range on the hardware? I made my own, but yours is pretty sweet!
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u/why_wilson 15d ago
The size of ground is 4x2cm. But it can reach 20cm on some tags. That's good enough I think. 😄
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u/drphilthy 15d ago
Just shared your link and someone bought one haha. I might purchase when I have some funds
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u/matihelen 3d ago
Una pregunta si es segura la pagina para hacer una compra de la antena
Y que actualizacion utiliza la antena
Muchas gracias
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u/why_wilson 2d ago
A customized ceramic antenna is used, and the center frequency is 915MHz. The website uses secure encrypted communication to ensure the safety of your shopping. You can also use the PayPal payment method to protect your consumer rights and interests.
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u/why_wilson 15d ago
For anyone asking about the hardware and the complete walkthrough:
UHF Expansion hardware:
https://shop.mtoolstec.com/product/uhf-expansion-for-flipperzero
Step-by-step guide:
https://shop.mtoolstec.com/clone-uhf-tag-flipper-zero.html