How to set bitrate on the ST25R3916 GUI app and read 14443 tags and general performance questions

[PCzym.1]

Hello,

we have developed a custom antenna and modified the reader circuit a bit to our needs, but are heavily struggling with reading performance. While we were able to read up 17cm above the MB1441-C Discovery Board using ISO15693 tags, our own circuit struggles to get even close to 5cm when using the MB1396-B, when using our own MCU it gets even worse (below 1cm). The layout and design is close to the reference one.

So we found an antenna expert doing some simulations for us, while we try to find the root cause as well. In order to do a model simulation we would like to test the reading range with 14443 tags at a set bitrate of 848kbit/s inside the GUI. How can I set the bitrate to a specific value and run a continuous scan on the RF Field?

What is the best place to start to measure and improve the design to find the root cause? What should we measure and what are the expected values in order to tune the antenna properly?

Cheers,

Philip

[Ulysses HERNIOSUS · Accepted solution]

Hi Philip,

ISO14443A always starts at 106kbps. For talking at 848kbps the reader needs to send a PPS command. For this you need to activate the card in ISO14443A tab to 848 and then switch to debug tab to send some APDU with alternating 0x02 and 0x03 byte (use the "alternate LSB" checkbox). Please beware that once the tag moved out of the field the communication stops and tag needs to re-activated.

Did you check AN5276? It should have quite some details on antenna matching/measuring/etc.

Best Regards, Ulysses