HOW TO READ DATA FROM A REGISTER USING SPI

[RJD]

Hello, i have been unable to read data from my sensor. 

uint8_t SPI_ReadByte(uint8_t RegAddress)
{
ret_code_t retCode = NRF_SUCCESS;
//start reading sequence
m_tx_buf[0]=RegAddress|0x80;
m_tx_buf[1]=0x00;
retCode = nrf_drv_spi_transfer(&spi_master,
m_tx_buf, 3,
m_rx_buf, 3);
APP_ERROR_CHECK(retCode); // NRF_ERROR_BUSY

NRF_LOG_HEXDUMP_INFO(m_tx_buf,2);

return m_rx_buf[3];
}

[Håkon Alseth]

Hi,

 

Are you setting up the nrf_drv_spi in non-blocking mode? If yes, then it is expected to see NRF_ERROR_BUSY if you do not wait until the former SPI transaction is done.

Please see the nRF5 SDK example "peripheral/spi/" and look at how it handles variable "spi_xfer_done".

 

Kind regards,

Håkon

[RJD]

Hello, I am actually using that same code, its just an additional function in it. I am not getting anything. How to set it up in non-blocking mode?

[Håkon Alseth]

Hi,

 

If you set the spi event handler to "NULL" when initing nrf_drv_spi, then you're setting the driver in blocking mode. If you init with an event handler, then its in non-blocking mode.

In your case, you can either set it in blocking mode (set event handler to NULL) or handle the _BUSY return in your SPI function.

 

Kind regards,

Håkon