PN7642 Finalizing the Transaction

[asknxp]

Hi there,

We are implementing a reader application to communicate with google wallet. We are able to get the application data from google wallet but the phone will display "phone moved too fast".

Based on vendor's documentation

In order for the smartphone to correctly detect that a transaction has finished, the reader must perform a final command sequence above and beyond what is normally required for physical credentials. It requires to send commit transaction command is as follows:

90 AA 00 00 00

Field Length Value
CLA 1 0x90
INS 1 0xAA
P1.,P2 2 0x0000
Lc 1 0x00

We did use "phhalHw_Transmit" to send the command without responding any error but phone will display "phone moved too fast". If we use "phhalHw_Exchange", then got the error response code: 0x0201 and phone also displays "phone moved too fast".

Any suggestion?

Thank you very much.

--Kenny

[Fabian_R]

Hello, my name is Fabian, I've been assigned to support your case.

Thank you for your interest in our products

Could you please clarify if you are using our NFC Reader Library examples running in the PN7642?

It would be great for me to understand what's the starting point with the PN7642.

[asknxp]

Hi Fabian,

Yes. We did use NXP reader library. Our application is based on example pnev7642fama_NfcrdlibEx2 example and extend the functionalities.

As what I described pervasively,  pn7642 needs to send vendor specified COMMIT TRANSACTION command. The following is something we try to do. However, it seems google wallet does not receive it or somehow did not take effect. I am wonder if we need to use other API call instead of phhalHw_Transmit or phhalHw_Exchange since I have tried phhalHw_Transmit or phhalHw_Transmit but none of them works.

Any suggestion?

int SendCommitCommand(void *pHalDataParams)

{

    phStatus_t status;
    uint8_t commitCmd[5] = { 0x90, 0xAA, 0x00, 0x00, 0x00 };

    // Exchange the command with the card
    status = phhalHw_Transmit(pHalDataParams, PH_TRANSMIT_DEFAULT, commitCmd, sizeof(commitCmd));
    if(status != PH_ERR_SUCCESS) {
        DEBUG_PRINTF("Failed to send commit command, status: 0x%04X\n", status);
        return -1;
    }
    return 0;

}

Thank you very much

--Kenny

[Fabian_R]

Hello sir,

There are some things that I haven't quite understood.

Since you are using pnev7642fama_Ex2_Ctrdlib_ISO7816_Freertos this example is intended for be used with a contact transceiver. In this example's case, the TDA8035.

I must clarify that the Ex2 example doesn't have any contactless interfacing.

Regarding the use of Google Wallet, I cannot provide a lot of support since, I am not quite familiar with this implementation. Since Google Wallet works on top of ISO 14443, is possible that the implementation can be done using a Host Card Emulation example (Ex8) or, to build on top of the nfc_examples options available in the SDK.

But, I have to recommend to please request more information regarding Google Wallet from Google support.

[asknxp]

Hi Fabian,

Sorry about the confusion. The example we extended is from NfcrdlibEx1_DiscoveryLoop.

We have another reader product using other vendor's chip and google wallet can respond with proper behavior. That is the reason I am wondering if I used the wrong API call for sending 

the vendor specified command 90 AA 00 00 00

Field Length Value

CLA	1	0x90
INS	1	0xAA
P1,P2	2	0x0000
Lc	1	0x00

Do you have any suggestion for sending command like that to PICC end?

Thank you very much.

--Kenny

[Fabian_R]

Hello,

Thank you for the clarification.

The DiscoveryLoop example is in charge of detecting different technologies based on ISO14443, ISO18000 and ISO 15693. This example can detect any device that is or emulates a card based on the mentioned technologies.

Since Google Wallet is based in ISO 14443 the reader should be able to pickup the emulated PICC. But, keep in mind that this example isn't sending APDU commands, Discovery loop is sending ISO 14443-3 commands for Initialization and Anticollision. These commands aren't ISO 7816-4 commands (APDU commands). This may be the issue.

In order to do so, please try with the Nfcrdlib_EMVCo_InteropComplApp and Nfcrdlib_EMVCo_LoopBackComplApp

But please, take a closer look at the Google Wallet documentation there should be a recommended environment for a PICC <-> PCD testing.

Is possible that the use of our USB CCID example may be helpful for you to start testing.

[asknxp]

Thanks Fabian.

Let's me try your suggestion and see how it goes.

--Kenny