Jose Vicente Campos

@FelipeC31024269 Hola Felipe, acabo de darme cuenta que tu mensaje es de hace 1 año! lo siento mucho no se porque no lo vi

Si te gusta el mundo del NFC, o simplemente tienes curiosidad por aprender, prueba la nueva versión del nfc-laboratory github.com/josevcm/nfc-la…

@gentilkiwi Hello Benjamin! I am surprised by the good capture you have obtained with a simple NESDR! Thanks!

Failed (non tuned)🥝antennas are good for cheap NFC spying Always amazing times when playing with @Jose4Vi's NFC laboratory... trust me and give it a try!

@gentilkiwi @airspy_com @bvernoux Thank you very much for your work to improve nfc-laboratory Benjamin!

Pushed a PR to @Jose4Vi amazing NFC laboratory to be able to use @airspy_com / @bvernoux 's Spyverter with Bias Tee (power from antenna cable, no need additionnal USB) No need to rely on harmonics ⚡️ > github.com/josevcm/nfc-la… > airspy.com/airspy-r2/ & airspy.com/spyverter-r2/

@5ch4um1 @jilles_com Have you tried to decode the bytes of the signal to get valid messages from the reader and card in all possible speeds and modulations? If there is any way to improve the decoding I am interested.

@Jose4Vi @jilles_com idk, worked just fine for me with gnuradio. Even at 2.12 msps iirc. You might want to play a bit with the placement of the components, like tag, reader and antenna? If you find a sweet spot, even the responses come in loud and clear. ;)

@5ch4um1 @jilles_com the signal simply does not have enough dynamic range to properly detect the symbols, the card responses are very weak compared to the signal level due to the 8 bit resolution, this means that good results are not obtained using RTL-SDR , that's why I recommend using Airspy.

@Jose4Vi @jilles_com "Only [...] some responses " still sounds supersticious to me, you either can get the responses, or you can not, because something is wrong with your setup. There is no voodoo involved that makes some responses disappear due to sample rate or bit depth imho?

@5ch4um1 @jilles_com There is nothing wrong with a classic RTL-SDR receiver, simply to decode NFC signals it is not the best option due to its bandwidth and the resolution of 8 bits per sample. Especially for the load modulation generated by the card.

@Jose4Vi @jilles_com "only some responses in very clean signals", because sample rate and only 8 bits ? Still sounds strange to me...I mean, sure, if you're half a meter away you probably won't get a clean signal, but why blame the receiver when it has nothing to do with it?

@5ch4um1 @jilles_com The main reason to need 10Msps (or more) is the complexity of decoding the card responses at high speeds like 424kbps, it is necessary to determine the shape of each symbol, the niquist frequency is not enough for it.

@jilles_com Wow, that looks like a lot of work. Why the concerns about the rtlsdr though? With 3 mbps, you are almost at 30 times the symbol rate of nfcA, plenty to make Mr. Nyquist happy?

@giammaiot2 @hydrabus @CyberAntani Hello, I am the author of nfc-laboratory, I think we are a great community in which we all contribute, once the misunderstanding has been clarified, let's continue working to help each other.

@hydrabus @CyberAntani I repeat that nowhere has it ever been indicated that the work belonged to anyone other than his, do not stir up and collect grudges with people who study and do not seek money.

GiamMa-based researchers SDR R&D IoT: UpDate: SDR nfc-laboratory v2.0: NFC signal and protocol analyzer using SDR receiver by josevcm giammaiot.blogspot.com/2021/09/update… #SoftwareDefinedRadio #NFC #signal #protocol #analyzer #SDR #receiver #RTLSDR #airSpy #RFID #HF #SmartCard #TAG

@giammaiot2 @cemaxecuter Hello, I am the author of nfc-laboratory if you need help let me know

@cemaxecuter The code is not mine, but on github they opened an issue to understand how to install and / or compile. I received an .exe but I don't think I can share it.

and let's see what can be done...