Trouble getting SPI to work together with BLE

These are my project files

I do not see any obvious reasons for why this works fine without BLE, but not when it's enabled. You haven't changed the pinout by any chance? I notice you are using P0.02 for the chip select line and that you have set the CONFIG_NFCT_PINS_AS_GPIOS option, but have you also remembered to short R42 and R45 and remove the 0R resitor on R43 and R46 on the board?

NFC antenna interface

A scope or logic analyzer capture of the SPI transfer would be helpful if we need to troubleshoot this further.

Thank you for your response,

In the original SPI code, I used P1.01 for the chip select. After combining the SPI code and BLE code I got the same issue I described in this post. I found somewhere that P1.01 might be used by the BLE connection, so I tried another pin (P0.02) for the chip select. I did not know about the need to short/remove the resistors from the board to use P0.02. Perhaps using another pin is more convenient in this case. I will try some others.

I sadly do not own a scope or a logic analyzer, but I might be able to borrow one if using another pin for the chip select does not help. 

Thanks for your help,

C

I have tried using several different pins from the GPIO_0 and GPIO_1 for the chip select, but none of them seem to be working. Using a logic analyzer does show that the chip select seems to be malfunctioning (see picture). In this test, P1.01 was used as the chip select pin, as that was the pin that was working in the original code. I have attached the original code used to set up the SPI connection.

Hi,

Can you try use P1.04 for CS instead? P1.01 is assigned to the network core for UART0 TX by default and therefore not accessible for the app core.

	gpio_pin_configure(gpio_dev_1, 4, GPIO_OUTPUT);
    gpio_pin_set(gpio_dev_1, 4, 1);

Edit: P1.01 ("33") gets assigned to the network core in the startup file here: https://github.com/nrfconnect/sdk-zephyr/blob/c3208e7ff49d22d8271f305344382e9306fdde99/boards/arm/nrf5340dk_nrf5340/nrf5340_cpunet_reset.c#L35

I have changed it to P1.04, but still no luck. For some reason, the rx_buffer seems to remain empty. The function ADS1200_poll_new_data does return 'true', as the data channels are printed (bottom of main.c). That indicates that 'new_data_available' (in ADS1299.c) must also become true. It seems like the code thinks data is received successfully, but either only zero values are received, or the data is not stored properly.

I have changed it to P1.04, but still no luck. For some reason, the rx_buffer seems to remain empty. The function ADS1200_poll_new_data does return 'true', as the data channels are printed (bottom of main.c). That indicates that 'new_data_available' (in ADS1299.c) must also become true. It seems like the code thinks data is received successfully, but either only zero values are received, or the data is not stored properly.

Did the CS signal start working now when you changed to P1.04?  And what is the difference between the non-working BLE example and the old SPI example if you look at the logic trace?

I don't have this sensor to test with, but I can at least check what gets sent. Here are a few screenshots from when I ran your code on a DK:

The CS indeed seems to be working now and, looking at the MISO, the ADS1299 looks to be transmitting data to the nRF5340. However, the rx_buffer still only contains zeros, so the data is not stored properly.

So the sensor is clearly clocking out data on the MISO line. Do you know what changes to do you need to do to make the it work again, is it sufficient to just comment the BLE calls in your application, or do you also have to remove the kconfig symbols that enables the BLE stack?

Commenting out the BLE call is not enough to make it work. Only when the bluetooth is disabled in the kconfig, the proper values are received again via the SPI connection.

Thanks for confirming. Could you compare a transaction of when the BT stack is enabled against one where it's not and see if there are any differences in timing, etc? Also, if the PIN_CNF[<miso pin>] and PSEL.MISO configuration stays the same when you enable BLE.