SPI instance 1 configuration

[Lakshmikanth Satyavolu]

Hi all,

I am using 2 SPI's in my design. I enabled  SPI0_ENABLED and SPI1_ENABLED in my sdk_config.h. 

SPI0 works fine. But SPI1 MOSI pin always sends 0xFF. 

My pin configuration is like below: 

CS = PO_08

SCK = PO_04

MOSI = PO_06

MISO = PO_07 

Are these pins have any conflicts with any other interface? Please help. 

Regards

Lakshmi

[Edvin]

Do you use a DK? Do you use logging over UART in your project? Check if NRF_LOG_ENABLED is 1 and NRF_LOG_BACKEND_UART is 1. If so, your project probably use the P0.06 as the UART pin, so it can't be used for SPI. Of not, can you please let me know what project you started out with?

Does everything else look like its running correctly? Do you check the return values of your function calls? Do any of them return a non-zero value?

BR,

Edvin

[Lakshmikanth Satyavolu]

@Edvin,

Thanks for helping. after NRF_LOG_ENABLED , it started working. I am using ble_app_hrs project(pca10040) as reference. for my custom design. 

Here is another thing I observed. nrf_drv_spi_transfer API takes uint8_t as transfer length size. Which is restricting my writes and reads from memory to only 256 bytes.

Is there any other API where I can send large number of bytes. 

Regards

Lakshmikanth

[Edvin]

The length of the buffer is a hardware limit. See TXT.MAXCNT. So if you want to send more data, you must separate it into chunks of 256 bytes.

Best regards,

Edvin

[Lakshmikanth Satyavolu]

Hi @Edvin,

In that case, can I control Chip select from the application to write into the internal SPI RAM continuously with the data to be sent? 

My application uses a flash memory where I need to send 512 bytes data at a time. 

Regards

Lakshmi

[Edvin]

Yes. You can control the CS pin manually from the application. Just use the NRF_DRV_SPI_PIN_NOT_USED when you initialize the SPI, and then set the chip select pin manually.

BR,
Edvin