Reading Irms and Vrms value from ACS71020 sensor using i2c protocol

[Saagar]

Hi

I am reading the Irms and Vrms data from the register 0x20 so i am using nrf_drv_twi_rx(&m_twi, ACS71020_ADDRESS, m_sample, sizeof(m_sample)); where we specify only device address so how can we know that the data we are getting is from same register.

Acc_gyro_datasheet.pdf

Thankyou

[haakonsh]

Do you not send the register address in your read command? 

[Saagar]

No as nrf_drv_twi_rx takes only device address

As per my understanding first we need to write to the register then we have to read data from that register

 uint8_t acc = V_I_RMS;

err_code = nrf_drv_twi_tx(&m_twi, ACS71020_ADDRESS, &acc, sizeof(acc), false);
APP_ERROR_CHECK(err_code);

err_code = nrf_drv_twi_rx(&m_twi, ACS71020_ADDRESS, m_sample, sizeof(m_sample));
APP_ERROR_CHECK(err_code);

[haakonsh]

I assume V_I_RMS is the register address you are trying to read, then my question is what is your current issue? What did you expect to observe and what did you actually observe?