TRF7970A: How to connect the TRF7970A to an ESP32 to read values from the RFID antenna using SPI

Hi Brian, 

I am working on a similar project as well (using the Teensy 3.6) so while I haven't got it completely figured out, I have been able to make some headway. First of all, are you using the TRF7970A on a custom PCB or using the EVM?

Hi Aayush,

I'm using it on a  custom PCB.

What stage is this PCB at, is this fully functional or are you still trying to design this as well? Ideally, you'd want to connect the EN(able) pins (both or just the one depends on your application, the data sheet has more details on this based on use case), the SPI pins (which you have already got covered), the clock pin from the MCU (DATACLK/SCLK), IRQ, MOD and ASK/OOK if needed. Have you had a chance to look at some of the reference PCB designs?

Our PCB is fully designed and we have the pins you mentioned. I haven't looked at reference PCB designs, can you link where they may be? We're trying to figure out how the antenna and the TRF7970 would detect an RFID tag in the antenna if you can help with that?

Hi, you can find the reference designs here - https://www.ti.com/reference-designs/index.html#search?keyword=trf7970a. As for the second part of your question, being able to do that relies on several factors being right, starting with the right PCB and antenna design (this is the transmitter antenna connected to the TRF7970A). As for programming over SPI and reading the values, you might want to look at the energia sketches since that's based on an Arduino compatible platform too and helps translate the NFCLink Library - https://e2e.ti.com/support/wireless-connectivity/other-wireless-group/other-wireless/f/other-wireless-technologies-forum/547894/how-to-get-the-sensor-data-from-trf7970a-evm. This should get you started, but you would have to be more specific about what you have tried doing so far and what isn't working.