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NFC Demo-Projekt PN7150, Mifare Desfire; restarting discovery loop problem

Question asked by davidwatzinger on Apr 10, 2017
Latest reply on May 2, 2017 by Jorge_Gonzalez



I´m using the Demoproject „NXP-NCI LPCXpresso example(REV 2.0)“ with a PN7150 NFC Controller. There is a problem with restarting the discovery loop. In the demo app the return value of the function NxpNci_StartDiscovery() is not checked at the end of the infinity loop. I have added this:


// Restart discovery loop

if(NxpNci_StopDiscovery() != NFC_SUCCESS) printf("Error in StopDiscovery()");

if(NxpNci_StartDiscovery(DiscoveryTechnologies,sizeof(DiscoveryTechnologies)) != NFC_SUCCESS) printf("Error in StartDiscovery()");


If there has been a communication with a mifare desfire card before restarting the discovery loop I get the response  0x61 0x06 0x02 0x00 from the PN7150 after calling NxpNci_StartDiscovery(). With other cards I get the expected answer  0x41 0x03 0x01 0x00. Shouldn´t be that independent with which card the communication has been done before?  I have not found something about this in the datasheets in docstore.  However the discovery is restartet and it works fine. But I want to know what this unexpected answer means.



Thanks in advance