Hi Ben, the typical workflow of a “dumb reader” like many that we sell is to return an ATR once a tag is detected and then take a command to query for other pieces of data on the card. This can all be done via the reader drivers published in our public GitHub repos for iOS and Android. Most of our customers don’t want to fuss with this workflow and just want the data off the card (most commonly an id or URL). The Flomio SDK was constructed on top of the published drivers to handle the reader workflow and return more meaningful data easily. The Flomio SDK is very much like the Android native NFC stack in that regard and perhaps what you aim to achieve with your Xamarin.iOS wrapper (which I think is awesome, BTW).

That said, I don’t think it makes sense for us to surface the raw ATR in the Flomio SDK interface but rather details about it that you’re interested in like Tag Type, # of memory blocks, etc. If you tell us what you’re looking to achieve we can add it in as time allows. If you rather work directly with the published drivers, we’d be glad to provide guidance on issues we’ve encountered with integrating with them ourselves.

best,
Richard

Hi Benjamin, it took a while to sort out but it helped that you pinged ACS as they prioritized the response to us because of it. As you’re probably aware, the manufacturer of the FloBLE Plus hardware, ACS, doesn’t have the best documentation so we have to wait on their engineers to get answers sometimes. The FloBLE Plus (ACR1255U-J1) driver doesn’t have native support for accessing ISO14443-Layer 3 commands like the FAST_READ command on the NTAG21X tags (pg. 39). That said, the reader driver does support the PCSC v2.0 interface and Part 3 of that spec delineates a protocol by which you can transparently send/receive commands to the target tag without having to interact with any reader middleware in between. This in effect is synonymous to the NfcA.transceive command on Android and the T=CL command option on the SLC010 reader, however it’s a different APDU command structure and (notably) more complex.

Here is a simple example of an PCSC 2.0 Part 3 APDU command sequence that you can send through the Flomio SDK sendApduToDevice(deviceSerialNumber)(apdu) interface:

// Start Transparent Session
<< FF C2 00 00 04 81 00 84 00 
->> C0 03 00 90 00 90 00

// Switch to ISO14443-3 Type A
<< FF C2 00 02 04 8F 02 00 03 
->> C0 03 00 90 00 8F 01 00 90 00

// FAST_READ (e.g. Start Addr: 00h End Addr: 04h) (Timeout value: 00 00 80 00h)
<< FF C2 00 01 0C 5F 46 04 00 80 00 00 95 03 3A 00 04
->> C0 03 00 90 00 92 01 00 96 02 00 00 97 14 04 29 D2 77 7A 97 3C 80 51 48 00 00 E1 10 6D 00 04 00 00 04 90 00

// End Transparent Session
<< FF C2 00 00 02 82 00
->> C0 03 00 90 00 90 00

You can look through the PCSC spec to understand what settings were chosen for each of these command/response pairs. Most confusing is the fact that data objects in Manage Session, Transparent Exchange, and Switch Protocol functions can be bundled into one command. So for instance, in my “Start Transparent Session” command I’m starting the session and turning on the RF field in one command. Also, the Timer data object needs to be used along with the Transparent Exchange Transceive data object in order to allow time between transmit of the FAST_READ command and the receive of the response from the target tag. This is set to 32ms or 0x00008000 (note the endianness swapping in the command).

We will be adding the PCSC 2.0 Part 3 interface into the Flomio SDK API to match the Android stack more closely. I hope the info above helps you in the interim though.

best,
Richard

• This reply was modified 7 years, 9 months ago by  Daniel.

Hey Ben, I suspect it’s a firmware problem since I didn’t send any specific commands beyond the ones I listed in the example. Latest version we ship with is FWV 1.16.03. If you send us your unit with a return label, we can reflash it for you with latest firmware. I could downgrade one of our units to test before doing that but unfortunately we don’t have any NTAG215 tags handy. You can send it to:

Flomio, Inc.
c/o Richard Grundy
7171 Bay Dr. Ste 9
Miami Beach, FL 33141

best,
Richard

Understood. We’re under contract with ACS to not share their flashing software as it could undermine their security model so we will have to update your unit internally. It might be cheaper and faster to purchase another unit on our site. Since you’re not really using the Flomio SDK, you can just purchase the ACR1255U-J1 as is. With shipping the cost would be just under $100.

If you send us some NTAG215s we’d gladly run your APDU sequence to check if the issue is still present in the latest firmware. We have an APDU scripting engine in our Test app that makes that pretty simple to do.

best,
Richard

Yes it would! But can’t share the latest firmware build until ACS “releases” it. 🙁

Good observation, check that and let me know. If it still fails then we’ll need to test on the latest firmware before I can escalate the issue with the ACS engineering team to reproduce the problem and resolve it for you.

The firmware flashing tool only works with Windows 7 and XP. If you’re using Windows 8 or 10 you will encounter driver issues like you described. Could that be your issue?

Hey Ben, I received the NTAG215 tags today. Seems the issue you’re seeing is indeed related to outdated firmware. Below is the APDU sequences I sent to the tag along with results. I confirmed the FAST_READ results match the data found in the tags.

// Start Transparent Session
<< FF C2 00 00 04 81 00 84 00 
->> C0 03 00 90 00 90 00

// Switch to ISO14443-3 Type A
<< FF C2 00 02 04 8F 02 00 03 
->> C0 03 00 90 00 8F 01 00 90 00

// FAST_READ (e.g. Start Addr: 00h End Addr: 04h) (Timeout value: 00 00 80 00h)
FF C2 00 01 0C 5F 46 04 00 80 00 00 95 03 3A 00 04
C0 03 00 90 00 92 01 00 96 02 00 00 97 14 04 BE C2 F0 72 C2 3E 80 0E 48 00 00 E1 10 3E 00 03 00 FE 00 90 00

// FAST_READ (e.g. Start Addr: 04h End Addr: 08h) (Timeout value: 00 00 80 00h)
FF C2 00 01 0C 5F 46 04 00 80 00 00 95 03 3A 04 08
C0 03 00 90 00 92 01 00 96 02 00 00 97 14 03 00 FE 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 90 00

// End Transparent Session
FF C2 00 00 02 82 00
C0 03 00 90 00 90 00

// Get Tag UUID, verify it matches with the block 00-01 data 
FF CA 00 00 00
04 BE C2 72 C2 3E 80 90 00

The last APDU command was just to get the tag UUID and verify that the first two data blocks returned from the FAST_READ command matched the data. Let me know if you will be sending us your reader to update for you or if you want to simply order some new ones from us.

best,
Richard

We only have FWV 1.15.00 beta1 in our repo so I was only able to downgrade to that for the confirmation test. Indeed the FAST_READ results are being truncated. Here’s another APDU sequence with the reader running FWV 1.15.00 beta1:

// Start Transparent Session
FF C2 00 00 04 81 00 84 00 
C0 03 00 90 00 90 00

// Switch to ISO14443-3 Type A
FF C2 00 02 04 8F 02 00 03
C0 03 00 90 00 8F 01 00 90 00

// FAST_READ (e.g. Start Addr: 00h End Addr: 04h) - RESULT TRUNCATED
FF C2 00 01 0C 5F 46 04 00 80 00 00 95 03 3A 00 04
C0 03 00 90 00 92 01 00 96 02 00 00 97 09 04 88 BE BA 72 C2 3E 80 0E 90 00

// FAST_READ (e.g. Start Addr: 04h End Addr: 08h) - RESULT TRUNCATED
FF C2 00 01 0C 5F 46 04 00 80 00 00 95 03 3A 04 08
C0 03 00 90 00 92 01 00 96 02 00 00 97 09 03 00 FE 00 00 00 00 00 00 90 00

// End Transparent Session
FF C2 00 00 02 82 00
C0 03 00 90 00 90 00

// Get Tag UUID, *does not* match the reported block 00-01 data 
FF CA 00 00 00
04 88 BE 72 C2 3E 80 90 00

I also checked the reported firmware version on the downgraded unit and it confirms what you found, the FWV is indeed misreported as 1.14.01. Seems like a flaw in ACS’s release process. I hope that clears things up for you to move forward with confidence. We’re here to help in any case.

Thanks for the willingness to refer customers our way. We’re really pushing for broad NFC adoption and feel closer to it than ever before. Please vocalize your support of our work on Facebook and Twitter as well as post product reviews for what you’ve purchased (click Review tab). It will certainly help keep our momentum going.

best,
Richard