I2C on K70

john71 — Thu, 15 Jun 2017 07:49:20 GMT

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?

Re: I2C on K70

john71 — Sun, 18 Jun 2017 05:55:20 GMT

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.

Re: I2C on K70

Jonathan_Iglesias — Mon, 26 Jun 2017 19:52:28 GMT

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 !

Re: I2C on K70

john71 — Tue, 27 Jun 2017 05:55:21 GMT

Thank you very much!

topic Re: I2C on K70 in Kinetis Microcontrollers

I2C on K70

Re: I2C on K70

Re: I2C on K70

Re: I2C on K70