SPIM, recieve on first transmit

Question

ADS1118: 
 
 How can I recieve the first 16 bits getting transmitted by the slave ? Will MOSI clock out p_txBuf while storing bits to arr_rxBuf if I set TX buffer len to 0, like this: 
 nrf_drv_spi_transfer(&spi, p_txBuf, NULL, arr_rxBuf, 2);

erltot · Accepted Answer

Never mind, I feel silly - I had misunderstood how the driver works. It works as expected now. 
 For reference, all data transmitted though MISO is stored in arr_rxBuf, for this case I just had to set 
 nrf_drv_spi_transfer(&spi, p_txBuf, 2, arr_rxBuf, 2);
 
 in order to read DATA MSB and DATA LSB. 
 For the other case: 
 
 I just had to call 
 nrf_drv_spi_transfer(&spi, p_txBuf, 2, arr_rxBuf, 4);
 
 and DATA MSB, DATA LSB, CONFIG MSB, and CONFIG LSB is recieved in arr_rxBuf[0..3]

SPIM, recieve on first transmit

Top Replies

core_v2_widget.Hide()