Proxmark3 community

genexis

Contributor

Registered: 2014-01-25

Posts: 78

Writing to a FOB using proxmark3

Hi all,

does anybody has any experience writing to a FOB? I bought some of these off the internet and they are supposed to be 125Khz, t55x7 fobs. However, i am not able to write to it using the same em410xwrite command, which was successful when i write to a t55x7 card.

link to fob: http://www.aliexpress.com/snapshot/6014159251.html
Features:
Weight: 47g (10pcs)
Size:40*32*4mm
Material: ABS
Operation frequency: 125khz
Detecting distance: 3-10cm
Compatible with all Door Entry system
Easy to carry
Water resistant
Each comes with Key ring included
Compatible with all RFID reader to gain access
No external power required.
Brand new key inductive card for entrance guard system.
It applies to access control, hotel locks, staff attendance and school campus access and payment control, identification and security systems, parking lot entry and payment, social security management, transportation payment, municipal and ancillary service payment.

vivat

Contributor

Registered: 2010-10-26

Posts: 332

Re: Writing to a FOB using proxmark3

Maybe it's not T5577. Can you launch lf read and then data samples 32000?

Cex

Contributor

Registered: 2009-12-14

Posts: 104

Re: Writing to a FOB using proxmark3

The fobs have a smaller antenna and work better with a smaller antenna on proxmark3.
Anyway try to program it putting the fogs at around 1cm distance from antenna and also putting the fob at an angle and not parallel to the PM3 antenna.

genexis

Contributor

Registered: 2014-01-25

Posts: 78

Re: Writing to a FOB using proxmark3

Hi all,

sorry for the late reply.
Vivat: It works well and reads like a tt55xx card which i have.
Cex: Tried that, at many different angles but still doesn't work.

What i did was use "lf em4x em410xwatch" and "data plot" to see which position has the strongest signal. With that, i tried to programme the fob at that position. However, i'm still not able to write properly into it.