I tried to connect STM32F103VET6 to NFC reader (PN532). As I read in pdf documentation of PN532 User Manual, i choose to use I2C. I didn't use the library of I2C, just use two GPIOs to analog the I2C communication protocol. The question is i didn't find the precise sequence diagram in the pdf.
In the pdf ,the following figure depicts the mechanism:
1. command sent by the host controller
2. the host controller polling the status byte
3. ACK frame sent by PN532
4.the host controller polling the status byte
5. RESPONSE frame sent by PN532
since i use the analog I2C communication protocol, the precise seqence diagram is very important to programming. I tried so many times and It doesn't work . May be there is something wrong..
Thank-you, see you on community.