PN532 Emulate not working randomly

[mdjavedakhtar]

Hi
i have tried emulating a card with PN532 module. it works like 1 out of 20 times

i debug i get tgInitAsTarget Failed or timeout

if i keep the phone on the pn532 with 1 sec timeout in sketch after about 20 retry i get data on phone. then again it stops.

i am using SPI connection.

[mywalkb]

Try to see if my changes mywalkb/PN532 improve your experience.
nfc.emulate use timeout 0, it don't give time to read response from chip, is not infinite timeout.

[jlkalberer]

@mywalkb - Can you explain what changes you're making in your branch?
There is a lot going on there and I'd like to understand the changes before I try to use your solution as I'm sure I'd only need parts of it.

These are the changes I added. I'm using a Particle Photon (not Arduino) so there are some slight differences. I haven't tested this yet but it compiles.
The other commits on your branch looked like it was for supporting callbacks which I don't want or need.

Cheers!

[mywalkb]

@mywalkb - Can you explain what changes you're making in your branch?

it's been over a year it's hard to remember all the changes and why I made them.
With my changes I tried to implement libnfc's functions which works very well with PN532.
I report the comment in my first commit:

- change include path
- fix some functions with readresponse when it's return 0 length (is not an error). Some other todo
- add setTimeoutComm for change timeout for command inCommunicateThru
- improvement function inCommunicateThru manage buffer len 0 so we can ignore response from TAG
- improvement function startPassiveTargetIDDetection manage better paramenters for all cardbaudrate

The other commits on your branch looked like it was for supporting callbacks which I don't want or need.

you can fork and remove that commit if you don't want it. When you emulate a tag without callback, how can you know when you receive data? Polling is not a good method in my opinion.

[jlkalberer]

Thanks @mywalkb

I took a lot of what you did and put it in this branch
I'll test this out and let you know if it works for me. If it does, I'll make a smaller patch and put a PR up on this repo.

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Polling is not a good method in my opinion.

Yeah, I'd generally agree with this but my code runs in a loop/state machine so a callback doesn't help me too much :)

[Cincinnatu]

Hello！Has this issue been resolved yet? If not, I will take a look at it soon.

[mdjavedakhtar]

Still the issue is there

[ackPeng]

@mdjavedakhtar Hello, I tested it using FeliCa_card_detection. After turning on the phone, I put the card on my phone and it can be recognized.

[jlkalberer]

I haven't been able to verify this yet but it I used another iOS app that could scan the emulated tag. I reached out to the author for details.

Basically, they had two reader implementations:

• NFCTagReaderSession - this is a newer, higher level API. It is not working for the scans.
• NFCNDEFReaderSession - this works for scanning the emulated tag.

I'm not sure if he manually wrote the protocol for reading the tag with NFCNDEFReaderSession or not but I know for a fact that it is working.

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As for Android... I'm still investigating.

1. I've seen it successfully scan NfcF (Felica) when I was using reader mode but it would crash the NFC stack on Android. So after the first scan which was successful, I had to manually reset the NFC service for it to scan anything.
2. Emulating with a MiFare application identifier would not work (or doesn't seem to be working).

[ackPeng]

@jlkalberer My phone is an Android system, and every scan is successful. I haven’t tried it on IOS yet. I’ll give it a try on IOS.

[ackPeng]

@jlkalberer I also tested it on an Apple mobile phone and it can also be detected.