icm20948 i2c

[Mohsin733]

Hello again ,
I make read write function separately reading all register giving me just right value except b0_control reg of bank 0 and B0_EXT_SLV_SENS_DATA_00 , B0_EXT_SLV_SENS_DATA_00 giving me zero value again and again , I am just verifying whoiam of magnetometer . I am adding all codes here please give a small review on that .

static void magnetometer()
{
select_bank(0);
read_data(0,B0_USER_CTRL);
write_data(0,B0_USER_CTRL,0x22,2);
read_data(0,B0_USER_CTRL);
write_data(0,B0_USER_CTRL,0x22,2);
read_data(3,B3_I2C_MST_CTRL);
write_data(3,B3_I2C_MST_CTRL,0x07,2);
read_data(3,B3_I2C_MST_CTRL);
write_data(3,B3_I2C_SLV0_ADDR,0x8C,2);
read_data(3,B3_I2C_SLV0_ADDR);
write_data(3,B3_I2C_SLV0_REG,0x01,2);
read_data(3,B3_I2C_SLV0_REG);
write_data(3,B3_I2C_MST_CTRL,0x81,2);
read_data(3,B3_I2C_MST_CTRL);
nrf_delay_ms(10);
select_bank(0);
read_data(0,B0_EXT_SLV_SENS_DATA_00);
}
void write_data(uint8_t ub , uint8_t regaddress , uint8_t regdata , uint8_t size)
{
writeregaddress=regaddress;
writeregdata=regdata;
len = size;
writeub=ub;
nrf_delay_ms(10);
select_bank(writeub);
nrf_delay_ms(10);
uint8_t writedata[2] = {writeregaddress , writeregdata};
err_code = nrf_drv_twi_tx(&m_twi, ICM20948addr ,writedata,len, true);
APP_ERROR_CHECK(err_code);
}

void read_data(uint8_t ub , uint8_t regaddress)
{
writeub=ub;
readregaddress=regaddress;
nrf_delay_ms(10);
select_bank(writeub);
nrf_delay_ms(10);
err_code = nrf_drv_twi_tx(&m_twi, ICM20948addr ,&readregaddress,1, true);
APP_ERROR_CHECK(err_code);
nrf_delay_ms(10);
read_sensor_data();
}

void select_bank(uint8_t bankselectvalue)
{
funbankselect=bankselectvalue;
shifted_value=funbankselect<<4;
bank[0]=bankselect;
bank[1]=shifted_value;
err_code = nrf_drv_twi_tx(&m_twi, ICM20948addr,bank,2, false);
APP_ERROR_CHECK(err_code);
}

void read_sensor_data()
{
m_xfer_done = false;
//NRF_LOG_INFO("1");
//NRF_LOG_FLUSH();

/* Read 1 byte from the specified address - skip 3 bits dedicated for fractional part of temperature. */
ret_code_t err_code = nrf_drv_twi_rx(&m_twi,ICM20948addr ,& m_sample, 1);
APP_ERROR_CHECK(err_code);
NRF_LOG_INFO("%x",m_sample);
NRF_LOG_FLUSH();
}

int main()
{
APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
NRF_LOG_DEFAULT_BACKENDS_INIT();
NRF_LOG_INFO("\r\nTWI sensor example started.");
NRF_LOG_FLUSH();
twi_init();
NRF_LOG_INFO("1");
NRF_LOG_FLUSH();
//ICM();
magnetometer();
NRF_LOG_INFO("end icm");

NRF_LOG_FLUSH();
}
and these are logs

app:
TWI sensor example started.
app: 1
app: 0
app: Register value = 32
app: 20
app: Register value = 32
app: 20
app: Register value = 129
app: 81
app: Register value = 7
app: 7
app: Register value = 140
app: 8C
app: Register value = 1
app: 1
app: Register value = 129
app: 81
app: Register value = 0
app: end icm

please reply , Thanks in advance.