OM5578 issues in Card Mode

[olegstepanov]

Hello,

I am working with the OM5578 NFC kit using the LPC82x host board. I am running "NXP-NCI MCUXpresso example Project Rev 1.2". I am having trouble in Card Emulation Mode.

Problem 1: Reader and Card Mode

I have both RW_SUPPORT and CARDEMU_SUPPORT symbols defined. When I run the example and try to scan the reader using the TagInfo app on an iPhone 8, I get an "Error - The reader session terminated unexpectedly" message in the app. Attached is a video.

Here's a photo of the error:

I also tried using TagInfo app using Galaxy S9 and it does not read the reader at all! The phone has no problem reading passive tags.

Problem 2: Card Mode only

With the RW_SUPPORT symbol removed so that the reader only works as a card emulator, the behavior is better but still problematic. I can scan the reader using iPhone 8 without any problems. However, using Galaxy S7 and S9, the TagInfo app takes a long time to read (shows spinny icon) and eventually shows an error message regarding communication. Below is a screen shot and here's the link to the video: https://photos.app.goo.gl/1LVnufyLxMxZFu3S7

Thanks very much! 

[Kan_Li]

Hi Max S,

The problem is due to you enable RW_SUPPORT in the same time, please refer to the following for details.

You may refer to https://www.nxp.com/docs/en/application-note/AN11658.pdf for more details.

Hope that helps,

Have a great day,
Kan

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[olegstepanov]

Hello Kan,

I need the PN7150 to be both reader and card emulator. It should be able to poll for and R/W to cards, while at same time also presenting itself as an NTAG to external readers, particularly the iPhone. I thought this is main benefit of the PN7150. Also the Note talks about Android. In my video, I using an iPhone to try to read the PN7150.

How can I put the PN7150 into both R/W and NTAG emulation mode?

Thanks

[Kan_Li]

Hello Max,

There is no problem to put PN7150 into both R/W and Card emulation mode, and in the implementation, PN7150 runs in a discovery loop for part time in RW mode and part time in CE mode, but for your case, there is limitation as mentioned above.

When the counterpart phone implement both reader and card emulation, if both modes are also supported on the PN7150 side, you can't presume in which mode devices will discover each side. This depends on the time of the tap versus the discovery loop instant. so you have to do something on the mobile phone side.

- Considering iOS version 12.0.1, the iPhone set in reader mode (done within a dedicated application) will only act as readers, so no issue in this case

- Android application can be designed setting NFC service in reader only mode (only when this app is in foreground) , which workarrounding this limitation.

Hope that helps,

Have a great day,
Kan

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[olegstepanov]

Hello Kan,

I tried this with an iPhone 8 running iOS 12.0.1 using a couple of apps from the Appstore and none of them are able to read the PN7150 successfully. Both apps display the "cannot read tag" message.

I also tried this with a Galaxy S9 and S7 using several tag reading apps with the same result. The difference between Android and iOS seems to be that Android is also acting as a card because the PN7150 detects an ISODep card when phone brought near.

Have you actually successfully been able to read the PN7150 with either Android or iPhone when the PN7150 in is Reader+Card Mode? It seems they are failing due to different issues.

[Kan_Li]

Hi Max,

For your case, you have to build  a custom App to support reader mode only.

Have a great day,
Kan

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[olegstepanov]

OK, but iOS NFC API doesn't even support card mode for developers. So I imagine it's only reader mode by default. 

What specific function or API in iOS sets it to "reader only" as you suggest? https://developer.apple.com/documentation/corenfc