Android NFC scan delay

Not really implant-related but…

I have an odd issue with that one cellphone (a Nokia 4.2): it takes forever to react to an NFC tag. I present the tag or implant, don’t move at all, then it can take up to 5 seconds for Android to react. I tried with other cellphone models / Android versions, and it ranges from instant read to a 2 second delay on those phones.

It’s just Android though - as in, the OS itself and intent system. When I have a dedicated NFC app up, like TagInfo, it scans instantly.

Anybody noticed that?

1 Like

Have you put a diagnostic card or field detector on it and see how often it pulses?

1 Like

My doNExT flashes every half second when the phone is too far, and then the blinkies turn on solid during the entire wait. So it does see the tag immediately. I just don’t know what the hell it’s waiting for before finally going beep.

Android phones in my experience send three small pulses followed by one large pulse I’m a repeating pattern, I know that my implant at least only reads on the large pulses, so I would guess that you’re just waiting for the large pulse sometimes or catching it others


Like the other guys said :arrow_double_up: something like this.
Same on my Tablet and phone etc.

As you can see (and have likley seen before), obvious power difference on pulses as it cycles through

1 Like

So this is a thing! When I used the diagnostic card on my phone I noticed a few faint blinks and then one bright one and that would repeat.

You can sniff this with the Proxmark3 and see it’s poking around the tag quite a bit and reselecting it a few times to… inefficient and wastes time.

The implants do the same but the tiny blinks are hard to see under the skin.

1 Like

That’s not at all what my cellphone does: it sends 5 strong pulses, then stays quiet for 5 to 10 seconds: Although it probably puts out a weak field that’s not visible with the detector, because tags are still detected when it’s quiet. When a transponder is in the field, it stays on solid until the transponder is removed.

I’m thinking the field detection / polling is handled by the NFC chipset itself, not Android, and different cellphones have different chipsets.

The problem is, when I bring a tag within range, it turns on, then waits… and waits… and waits some more, until at last it beeps. While it’s doing that, the field is full on. That must be Android spinning its wheels uselessly.

It doesn’t do that all the time. Sometimes it’s a lot faster. Dunno why. But the thing is, when I want to check my mail or my appointments (which I do by scanning either two of my 3 NFC implants), the stupid delay defeats the purpose: it would be faster to hit the shortcut manually.

Yeah I probably should try and see what’s going with the PM3.

I know it does a whole bunch of things for no reason because I had to sift through a lot of useless preamble to extract the relevant traces when I was trying to figure out the Dangerous NFC app issue a few weeks ago. But… 5 seconds? It must be trying to download a porn movie or something.

1 Like