X-NUCLEO-NFC03A1 reading STEVAL-SMARTAG2

[Mark_MT]

On both boards the demo application is installed, Oneshot on the STEVAL-SMARTAG2 and PollingTagDetect on the X-NUCLEO-NFC03A1.

When using the STEVAL-SMARTAG2 without battery it can be read however I always see the same sensor data. 

On the debug port its clear the program does not execute the function 'MEMS_Sensors_ReadData'

When energising the tag with a phone the function is executed. So the tag needs more energy.

The app does not show sensor data but the debug port of the tag shows the MEMS_Sensors_ReadData printing sensor data.

The PollingTagDetect needs to send more power to the tag, how can i increase the charging time?

[Brian TIDAL]

Hi,

the energy harvesting has been improved on the STEVAL-SMARTAG2 evaluation board second version. Make sure to have this second version. Check the silkprint on the PCB:

• STEVAL$SMARTAG2A: first version
• STEVAL$SMARTAG2B: second version with improved energy harvesting

On X-NUCLEO-NFC03A1 side, there is no easy way to increase the emitted power (except with some HW modifications on the board).

Rgds

BT

[Mark_MT]

Yes i have the B version. Its something else, when the PollingDetect prints 'Tag can be removed from the field' and i press the reset button on the nucleo401 the tag reads its sensors.

So a dirty solution for now is after this print in ' case RFAL_NFC_LISTEN_TYPE_NFCV:'

wait 5 seconds and reboot. This proves it is possible but what is blocking the tag executing its whole program?

[Brian TIDAL · Accepted solution]

Hi,

so if you have the STVAL-SMARTAG2 version B, this is not an energy harvesting issue.

I guess you use PollingTagDetectNdef application (please confirm) from X-CUBE-NFC3 (please confirm).

PollingTagDetectNdef polls for different technologies and as soon as a tag is found, the reader reads the NDEF message from the tag memory. Once the NDEF has been read, the tag presence is periodically checked until the tag is removed from the field.

The OneShot application has a 200ms delay after boot (OneShotAppStart line 90) and then initialize the I2C communication and disable the RF communication (OneShotAppStart line 107). This causes the reader presence check to consider that the tag has been removed from the field (no response) and to switch off the RF field.

PollingTagDetectNdef behaves as designed (i.e. loop on poll for tag --> read/write NDEF --> check the presence of the tag until tag is removed). In order to be able to use the OneShot application with PollingTagDetectNdef, a delay is needed after the reading of the NDEF to give additional time to OneShot for the processing of the various sensor and the update of the data inside the tag memory.

Feel free to customize the PollingTagDetectNdef to fit with your needs.

Rgds

BT