I2C on K70

[john71]

I have a problem connecting to I2C device.
This is how I read a register from the device

void INA226_ReadReg(uint32_t slave_adr, uint8_t reg_addr, uint16_t *value)
{
    uint8_t val[2];
    
    //first - write register address
    
    //for a write operation R/Wn bit should be low
    uint8_t slave_address = slave_adr  & 0xFE;  
    
    //start
    I2C0_C1 |= I2C_C1_TX_MASK;
    I2C0_C1 |= I2C_C1_MST_MASK
    
    /* send slave address with W/R bit */
    I2C0_D = slave_address;
    //wait for ack
    while((I2C0_S & I2C_S_IICIF_MASK)==0) {}
    I2C0_S |= I2C_S_IICIF_MASK;
    
    /* set register address */
    I2C0_D = reg_addr;
    //wait for ack
    while((I2C0_S & I2C_S_IICIF_MASK)==0) {}
    I2C0_S |= I2C_S_IICIF_MASK;
    
    //stop
    I2C0_C1 &= ~I2C_C1_MST_MASK;
    I2C0_C1 &= ~I2C_C1_TX_MASK
    

    //second - read from written register address
    
    //slave address for read
    slave_address = slave_adr | 0x01;
    
    //repeated start
    I2C0_C1 |= I2C_C1_RSTA_MASK;
    
    I2C0_D = slave_address;
    //wait for ack
    while((I2C0_S & I2C_S_IICIF_MASK)==0) {}
    I2C0_S |= I2C_S_IICIF_MASK;
    
    
    // Put in Rx Mode
    I2C0_C1 &= (~I2C_C1_TX_MASK);

    // Turn off ACK since this is second to last byte being read
    I2C0_C1 |= I2C_C1_TXAK_MASK;
   
    val[0] = I2C0_D;
     //wait for ack
    while((I2C0_S & I2C_S_IICIF_MASK)==0) {}
    I2C0_S |= I2C_S_IICIF_MASK;
    val[1] = I2C0_D;
     //wait for ack
    while((I2C0_S & I2C_S_IICIF_MASK)==0) {}
    I2C0_S |= I2C_S_IICIF_MASK;
    
    *value = (val[0] << 8) | val[1];
    
    //stop
    I2C0_C1 &= ~I2C_C1_MST_MASK;
    I2C0_C1 &= ~I2C_C1_TX_MASK
}

It stucks on wait for acknowledge.
while((I2C0_S & I2C_S_IICIF_MASK)==0) {}
I2C0_S |= I2C_S_IICIF_MASK;

May be I do something wrong?

[john71]

I replaced

while((I2C0_S & I2C_S_IICIF_MASK)==0) {}
I2C0_S |= I2C_S_IICIF_MASK;

with

while((I2C0_S & I2C_S_IICIF_MASK)==0)
 {
          timeout++;
          if(timeout > I2C_TIMEOUT)
            return I2C_ERROR;
  }

And now I see the first part - slave address and register address. But no repeated start.

[Jonathan_Iglesias]

Dear Evgeny Erenburg,

I will attach some generic examples used in other devices please check the process that it follows to communicate using I2C.

have a great day !

[john71 · Accepted solution]

Thank you very much!