SPI in BLE_UART example, clock not working

[noob_with_ucontrollers]

Hi, 

I am trying to read data via an ADC through SPI and send it via Bluetooth to the NRF mobile app. I checked that both the original BLE_UART example and the SPI master code work properly on my custom board when flashed separately, My custom pcb is nrf52382 based, I used SDK 15.2 in Embedded Studio to program it. 

When I include the SPI code in the ble_uart example, the chip advertises, and I check that the nus_data_handler is called as well. But SPI part does not work. My chip select is low, MOSI is low, so I see that gpio pin initialization works. But I do not get a proper clock signal from nrf to ADC. This clock pin is pin 7. I don't know why the BLE would interrupt with spi clock functionality. Pin 7 is not being used anywhere else in the code I checked the sdk_config,h file. 

More details on code: my code is not complicated. I was debugging my problem so I am using most of the functions in the SDK without modification, I remove the uart and NRF_LOG functions from the ble_uart example so that my pin 6 can work (this is my chip select pin for ADC). Then I initialize the SPI instance and pins etc. I am NOT trying to communicate with the SPI just yet, for starters I was  trying to simply initialize it and see if the clock is good before I actually transferred data. 

Any ideas or suggestions that would help debug the problem are appreciated. Thanks!  

I know there is another ticket by the same title, I started that but didn't get help, and the issue persists. 

[Kenneth]

Hi,

Can you for testing try any of the pins that is not by default configured and used as UART (5, 6, 7, 8) by the nRF5 SDK? 

Then you can isolate if the problem is related to overlapping configuration with UART somehow and/or a completely different issue.

Best regards,
Kenneth

[noob_with_ucontrollers]

Kenneth Thank you for your response. 

I tried toggling pin # 7 as a simple GPIO in my edited ble_uart + spi code and it toggles just fine. 
I tried using pin 11 instead of 7 for SPI_CLK but I still cannot see any clock signal on it. The same pin (11) gives a proper clock on the original SPI master example through so I'm sure it's not the pin that's the issue.

Should I share my sdk_config.h file with you? In the ble_uart example sdk_config.h file I added the spi pin definitions, included the spi header, and then went on to enable spi master, nrfx_spi, and the timers. Not sure I need to do something else as well to use spi in this project..

I also wanted to mention my interrupt priority is 6 for the SPI in the ble_uart ex and that I did make sure my timers are enabled, if that matters in any way? 

[noob_with_ucontrollers]

Just an update.

this is the "signal" I get on the clock pin when I tried flashing my ble_uart + SPI code on the Dev Kit board connected to the ADC instead of my custom pcb. The results are the same again, ble works but spi doesn't. 

[Kenneth]

Maybe you can take a look at this code that seems to work: 
https://devzone.nordicsemi.com/f/nordic-q-a/37926/nrf52810-sd-spim 

Notice he is using the nrfx SPIM driver directly, without the legacy nrf spi api.

Best regards,
Kenneth

[noob_with_ucontrollers]

So I looked into merging the nrfx SPIM example with ble_template. 
 But in SDK 15.2, the nrfx_spim example is only for 10056 and there's no folder for 10040... 

Can I run the 10056 project code on a custom made PCB that uses nrf52382 (no PCA at all)? 

Specifically, can I run this line of code on a NRF52382?  nrfx_spim_xfer_desc_t xfer_desc = NRFX_SPIM_XFER_TX(data, 2);

[noob_with_ucontrollers]

I saw another project that uses SPIM with nrf52810 as well. But I haven't seem spim being used with nrf52382 yet.. 

[hmolesworth]

Nothing like asking an obvious question, but just in case ..

.. then I initialize the SPI instance and pins etc. I am NOT trying to communicate with the SPI just yet

SPI will have no clock activity on SCK (pin 7) just by initialising the SPI driver, other than the pin being pushed to the '0' or '1' level as specified by the SPI Mode. the clock is active only for 16 cycles (for example) if the SPI transfer packet is 2 bytes, after which the pin will go quiet. If there is no SPI communication attempted, there will be no activity on pin 7 (SCK).

If I misunderstood your sequence then just ignore this :-)

[noob_with_ucontrollers]

No that might not be the problem. 

Even when I run the data call /spi transfer function once every time in the main loop, the clock for the SPI doesn't work.. 
My SPI works fine in the SPI example project. The same code doesn't transfer data properply when it's added in a ble_template or a ble_uart_example.. 

I tried removing all the BLE functions from the BLE _UART example project and then running just the SPI code but that doesn't work either.