Listening to an NFC Polling Signal from a Nexus 7 with an RTL-SDR
Over on YouTube user 2e26tenW has uploaded a video showing reception of the second harmonic of an NFC polling signal with his RTL-SDR. NFC stands for “Near Field Communication” and is a technology that enables smartphones and other devices to communicate with one another and some smart cards simply by bringing the two devices together.
In his experiment he uses a Nexus 7 tablet to poll an NFC enabled transportation card. As the RTL-SDR cannot receive the NFC frequency of 13.56 MHz directly without an upconverter or hardware or software direct sampling modified dongle, 2e26tenW instead tunes to the second harmonic at 27.12 MHz which allows him to receive the signal.
Nexus 7 NFC polling signal (2nd harmonic)
A tool that can read the commands off an NFC reader using an RTL-SDR:
the most interesting think are when there is a software who allowed me to read the transaction.