NRF24LE1 IIC problem

[I6believe]

hello,we want to use NRF24LE1 IIC to communicate with NFC cards.

firstly,we choose NRF24LE1 IIC(hardware),but it is failed.
then,we use simulation of IIC(software) to communicate with NFC cards successfully,
but real-time performance does not meet the requirement.
so,we should dubug NRF24LE1 IIC(hardware) again.

we have watched the wave of IIC timing(hardware) by a oscillograph,
and found the timing is not correct.

please give me some advise,thank you very much!

the code is as follows:

main program:

CLKCTRL = 0x28;//配置时钟
CLKLFCTRL = 0x01;

IIC_init();//IIC初始化

writebyte(0,0xA5);

rbuffer[0] = readbyte(0);

subprogram:

#define READY (W2CON1&0X01) //if ready ==1,not ready==0
#define ACK (W2CON1&0X02 ) //1;no ack and 0 ack
#define EN2WIRE() W2CON0|=0x01; //enable 2 wire
#define DISABLE2WIRE() W2CON0&=0xFE;
#define STOP() W2CON0|=0x20;
#define START() W2CON0|=0x10;
#define FREQSEL(x) W2CON0|=(x<<2); //1 100K 2 400K
#define MODE(x) W2CON0&=(0xff-0x02);W2CON0|=x; //master or slave

void IIC_init()
{
EN2WIRE(); //使能2-wire

FREQSEL(1);//100KHz

MODE(MASTER);//主模式

W2CON1|=0x20; //屏蔽所有的中断

}

unsigned char readbyte(unsigned int addr)
{
unsigned char byte;

START();
W2DAT=(unsigned char)(slaveaddr+0);//write from slave
while(ACK);
W2DAT=addr;
while(ACK);
START();
W2DAT=(unsigned char)(slaveaddr+1);//read from slave
while(ACK);
while(!READY);
byte=W2DAT;
STOP();
return byte;
}

void writebyte(unsigned int addr,unsigned char dat)
{
unsigned char byte=dat;
START();
W2DAT=(unsigned char)(slaveaddr+0);//write
if(!ACK) //IF ACK
W2DAT=addr;
if(!ACK)
W2DAT=byte;
STOP();
}

[Kenneth]

Hi, can you show with a screenshot what timing is problematic?

[I6believe]

after reading or writing data according IIC,the SCL level is low.

please give me some advise,thank you very much.

[I6believe]

after i use interrupt for IIC communication,SCL level sometime is correct,sometimes it is low,and then it cannot communication.

the details is as below:

when reading data from EEPROM,the first times communication is well,and then the communication is halted because it cannot trigger 2 wire transmitted/received interrupt,and SCL level is low. in other words,it cannot realize Continuous reading communication.

writing operation goes well after using delay function.

please give me some advise,thank you very much.

[Kenneth]

My suggstion is to use the 'hal_w2.c' (IIC compatible) library from nRFgo SDK v2.3. You can find example usage of the library in the 'display_joystick_example'. This library contain a workaround for a deadlock condition that may occur on the interface if there is a NACK condition. In specific check out hal_w2_soft_reset() in hal_w2_read().

[I6believe]

thank you,IIC is ok.

thank you very much!