Issue in SPI communication and waveform

[tusharrdtc]

Hello everyone

I am working on nRF52DK devkit. I want to check the SPI waveform. Actually I want to interface waveshare e-paper display (1.54 inch) For that i used GFX library provided in SDK 17.1.0. but i am unable to interface display with nRF board. When i checked the SPI signal on DSO, I found that there no any SPI signal on DSO. So i decided to go with SPI example given in example section of nRF SDK 17.1.0. So i uploaded the SPI example in nRF52DK but again I can not see the proper SPI waveform. Can you please tell me the why i can not get the proper SPI waveform. Below are the specs i am using. 
                

- IDE: SEGGER Embedded Studio (V6.20a)

- Development Board: nRF52DK 
- SDK:  nrf SDK 17.1.0 

- DSO : I am using HANTEK DSO check waveform. I have attached the screenshot of DSO screen when i was trying to capture SPI signal. Yellow signal :Clock Signal, Green signal: MOSI signal.

[JONATHAN LL]

Hi,

What example did you use?

How do you connect to the nrf52DK?


SPI Master Example: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/spi_master_example.html 

nRFX SPI sample: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/nrfx_spim_example.html 

SPI Slave Exampel: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/spi_slave_example.html 


Maybe interesting link: Overview on SPI Master / Slave on nRF52 Series – JimmyIoT (jimmywongiot.com)
nRF5 SDK - Tutorial for Beginners Pt 36 A - Introduction to SPI Communication - YouTube


Regards,
Joanthan

[tusharrdtc]

Hi Jonathan LL,

Thanks for reaching.

I am using the same example which you have mentioned in the link

SPI Master Example: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/spi_master_example.html . Here are the below my pin connections with nRF52DK. I build the code and uploaded code directly as it is to nRF52 board.

SPI_SS_PIN = P0.31
SPI_MISO_PIN = P0.30
SPI_MOSI_PIN = P0.29
SPI_SCK_PIN = P0.26. 

I checked nRFX SPI sample (https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/nrfx_spim_example.html) example but the example is for only PCA10056 board and i have PCA10040 development board.

[Jørgen Holmefjord]

Hi,

Is the problem in the waveform that some of the signals have a lower peak amplitude? You can try to increase the GPIO drive strength by calling nrf_gpio_cfg() with drive parameter set to (NRF_GPIO_PIN_H0H1) after spi_init.

Best regards,
Jørgen