SPI Slave not working on nRF9160DK

[mike.bush.valtech]

Hello,

I'm trying to get some basic SPI communication between the nRF91 and nRF52 chips on the nRF9160DK. We have been using UART for this communication however we want to move to SPI so we can connect some additional chips to the nRF52. 

Using the same interface lines as we were with UART1 I can see the data coming from the nRF52 chip across to the nRF91 on the logic analyzer, but for some reason the data isn't making it into the RX buffer on the nrf9160. 

Applications can be found here: https://github.com/mbush91/nrf9160dk_spi_test

To recreate: Grab a nRF9160DK, flash the nrf52 and nrf91 applications and open the usb consoles to see data.

I've tried both sync and async spi calls and the slave is even triggering on the master writes but the data doesn't match. 

[Menon]

Hello,

Is there any error message or error code? If not, try adding debug logs or using error handling to determine whether the SPI driver on the nRF91 is receiving and processing data correctly. Capture any errors returned by the spi_read calls on the nRF91 side.

One more thing I noticed while checking the application is that you have defined small buffers on both sides (rx_buffer[2], tx_buffer[2]). Ensure that the data you're sending fits into these buffers. If you're transferring more than 2 bytes, the buffer size should be adjusted accordingly.

Kind Regards,

Abhijith

[mike.bush.valtech]

Turn out the CS line from the master was active high instead of active low. For anyone needing SPI working on the nrf9160dk working sample can be found here: https://github.com/mbush91/nrf9160dk_spi_test