CLRC663 locks I2C

dcarro — Thu, 09 May 2024 16:17:57 GMT

Hello:

I have a code implementation for reading UID and write/read data for MIFARE CLASSIC tags that works fine using CLRC663 and SPI communication.

I am trying to use it with I2C communication but i have problems with the CLRC663. It is locking the bus after readings .

I can write data to CLRC663's registers and i receive I2C AKCs ( even i can perform NFC TX transmissions), but the CLRC663 breaks the bus after reading operations. CLRC663 sends a byte of data, but then it indefinitely holds SDA Low (SCL keeps high) and the only way i have to unlock the bus is manually sending pulses through SCL (revive_I2C() function provided or with a writing call).

I am following the information about the protocol provided in the datasheet of CLRC663 (8.4.4.8 I2C-register read access part).

I have checked the data with the osciloscope and I cut off microcontroler'SDA line in order to check which system is locking the bus. I also have tested the I2C communicaton with another devices and the bus work fine.

Could you help me? What could the error be?

CODE EXAMPLE

********************************************************

void revive_I2C()

{

if (input(I2C_SCL) && !input(I2C_SDA)) //IF I2C LOCKED

{

for (int i = 0; i < 9; i++)

{

output_low(I2C_SCL);

delay_us(10);

output_float(I2C_SCL);

delay_us(10);

}

i2c_stop();

}

void main()

{

int value;

#define I2C_CLR663_DIR_R 0b01010001

#define I2C_CLR663_DIR_W 0b01010000

i2c_start();

i2c_write(I2C_CLR663_DIR_W);

i2c_write(CLRC663_REG_STATUS);

i2c_stop();

i2c_start();

i2c_write(I2C_CLR663_DIR_R);

value = i2c_read();

i2c_stop();

printf("\n Readed: %x", value);

while(1)

{;}

}

***************************************************

The hardware i am using is a PIC microcontroler (with CCS) connected to a custom PCB with a CLRC66303 IC and an antenna. The I2C pullups are 1K resistors. IFx and IFSELx pin connections configured for I2C according with the CLRC663 datasheet. I tried severeal CLRC663 from several providers.

The IF/IFSEL connections are the following:

IF0 - GND IFSEL0 - 3.3V

IF1 - SCL IFSEL1 - GND

IF2 - GND

IF3 - SDA

Re: CLRC663 locks I2C

danielchen — Mon, 27 May 2024 11:17:40 GMT

I would suggest our customer use NFC reader library to develop their application, it is easier to use.

If you use the RC663 without library, please refer to AN12657.

For CLRC663 connects to host MCU through I2C, we need to check CLRC663 pins 23 and 24 are for I2C , pins 28 to 31 can be used either by a secondary I2C, SPI, or UART. Please keep in mind that pins 26 and 27. If you are using our evaluation board and trying to communicate with an external MCU, it is required to modify some resistor configuration.

These are shown in the next community document.
https://community.nxp.com/t5/NXP-Designs-Knowledge-Base/How-to-port-the-NFC-Reader-Library-to-Kinetis-K64F-MCU/ta-p/1119073

If you can read and write CLRC663 registers through i2c then i2c interface is working. If not working well, I would suggest you check the bus frequency.

NFCのトピックCLRC663 locks I2C

CLRC663 locks I2C

Re: CLRC663 locks I2C