How to send 40 bit data over spi in nrf52832?

[suvarna_kadam]

Hi

I am using nrf52832dk as master and slave for spi communication. I want to send below data over spi.
0x8000000008
0xEC000100C5

I am get confused in transfer function of spi.
ret_code_t nrf_drv_spi_transfer(nrf_drv_spi_t const * const p_instance,
                                uint8_t const * p_tx_buffer,
                                uint8_t         tx_buffer_length,
                                uint8_t       * p_rx_buffer,
                                uint8_t         rx_buffer_length)

As per this function, we can transfer 8 bit data.
For 40bit data transfer,is below method is correct?

m_tx_buf [6]= {0x80,0x00,0x00,0x00,0x08};
m_length =5;

nrf_drv_spi_transfer(&spi, m_tx_buf, m_length, m_rx_buf, m_length);

Need guidance is this correct method, or any other way to transfer 40bit data over spi?

[Julien_CARLIER]

Hi Suvarna, 

It seems to be good your method. You can try the transfer by shorting with a wire between MISO and MOSI pins . 

See the result by watch the variable content of rx_buf  after the nrf_drv_spi_transfer(...) 

[suvarna_kadam]

Hi Julien51,

I am using two nrf52- boards, one as slave and other as master.

[Julien_CARLIER]

Could you disconnect the wire between this two nRF52 ? And you connect a wire on MOSI and MISO pins on the master board. See the result :)