nRF52840 SDK16 - TWI Driver

[Nikosant03]

Hi everyone, I am using TWI driver to communicate with I2C. I have write the following I2C read function. 

/* TWI instance. */
static const nrf_drv_twi_t m_twi = NRF_DRV_TWI_INSTANCE(TWI_INSTANCE_ID);

int8_t Acc_i2c_Read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len) {
  int8_t rslt = 0;
  
  rslt = nrf_drv_twi_tx(&m_twi, dev_id, &reg_addr, 1, false); 
  APP_ERROR_CHECK(rslt);

  if (rslt == 0) {
    rslt = nrf_drv_twi_rx(&m_twi, dev_id, reg_data, len);
  }
  return rslt;
}

Now I want to write a second I2C function with some modifications. I will use the same TWI instance for it? For example:

int8_t My_I2C_Second(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len) {
  
  // Some modifications....
  
  int8_t rslt = 0;
  
  rslt = nrf_drv_twi_tx(&m_twi, dev_id, &reg_addr, 1, false); 
  APP_ERROR_CHECK(rslt);

  if (rslt == 0) {
    rslt = nrf_drv_twi_rx(&m_twi, dev_id, reg_data, len);
  }
  return rslt;
}

Thanks in advance

Nick

[Kenneth]

Hi,

You can use the same twi instance (m_twi) to read or write to a twi slave device multiple times, the same twi instance can also be used to read or write to several twi slaves devices, just make sure the previous twi transaction is complete before you update the dev_id and start next twi sequence.

Best regards,
Kenneth

[Nikosant03]

Thanks Kenneth!!