Hello.
I work as a hardware engineer at , a company in Korea that develops and sells kiosks and POS.
One of our international customers is using a third-party NFC terminal that uses the NXP PN7220. To verify the PN7220 specifications for our international NFC terminals, we purchased two NFC chips: the i.MX 8M MINI and the PNEV7220PB1. We have currently installed the Android 13 OS provided by NXP for the PN7220 demo and have successfully verified NFC functionality, including read/write capabilities.
I have two questions.
I have a question about the NFC tag recognition rate of the PNEV7220PB1 module and the USB-I2C connection of the PN7220 I2C interface.
First, I would like to inquire about the NFC tag recognition rate of the PNEV7220PB1 module. I have several NFC demo cards.
Only one NFC Type 1 tag (NFCA, ISO14443-3A) is not recognized properly.
Is this a known issue, or does it require additional tuning?
My next question is about USB connectivity via the PN7220 I2C interface.
I plan to connect an x86 Windows system and an Arm Android system via USB without removing the I2C port.
For x86 Windows, PnP support makes driver installation simple.
For Arm Android, do I need to compile or port a separate driver?
I plan to use the i.MX 8M MINI EV kit and the PNEV7220PB1.
The configuration involves the host side being Ardroid (Arm) or Windows (x86),
and the MCP2221A or FT4222HQ USB-to-I2C controller between the PN7220 and the host connection.
The PNEV7220PB1 has an external I2C host pin for I2C,
and I'm trying to connect USB to I2C via this pin.
First, can I use the external I2C host pin as a hardware configuration?
Also, USB-I2C only changes the physical components.
This is the NFC NCI protocol standard.
I'm wondering if the host needs to process the NCI protocol content through a separate driver or software via USB-I2C.
Or, can I just use a hardware-aware driver without any additional processing?
Also, I have a question about I2C speed. The standard I2C speed is 100kbps.
The PN7220's maximum I2C speed is 3.2Mbps. While I2C is compliant with the host speed, the problem here is that
the MCP2221A's maximum speed is 400kbps. Considering jitter through USB for EMVco payments, 400kbps seems insufficient. So, I'm worried that a bottleneck will cause operational issues. Is my guess correct?
However, the FT4222HQ supports up to 3.2 Mbps for I2C. Would using the FT4222HQ be a better choice than the MCP2221A?
Finally, if the above is correct,
I have a question about I2C pin matching and speed. Connecting the I2C SCL and SDA pins to the I2C lines of the mcp2221A or FT4222HQ communication conversion controller will also connect the PN7220 function pins: VEN (reset), mode switch, and IRQ. Fortunately, using two conversion controllers allows access to four GPIOs.
Can I connect the function pins as follows?
| PN7220 | USB to I2C | |
| I2C SCL | ↔ | I2C SCL |
| I2C SDA | ↔ | I2C SDA |
| VEN | ↔ | GPIO(Output) |
| Mode Switch | ↔ | GPIO(Output) |
| IRQ | ↔ | GPIO(Input) |
A positive answer would be appreciated.
