How to use SPI on nRF9160DK

[Linus]

Hi!

I am trying to get this example to work on my nRF9160 board:  https://github.com/Rallare/fw-nrfconnect-nrf/tree/nrf9160_samples/samples/nrf9160/spi/

It compiles and flashes just fine, and it seems to boot and run correctly:

***** Booting Zephyr OS v1.14.99-ncs1 *****
SPIM Example
TX sent: 0
RX recv: 0
TX sent: 1
RX recv: 0
TX sent: 2
RX recv: 0

However, the SPI pins (P0.10, P0.11, P0.12, p0.13) don't show any activity, they seem to be floating. The secure bootloader says that SPI3 is non-secure (​"12 NRF_SPIM3 Non-Secure OK").

I haven't changed the example code at all. I am using the v0.4.0 release tag, and building for the nrf9160_pca10090ns board using west.

Is there any more configuration that I must do?

Regards,

Linus

[Håkon Alseth]

Hi Linus,

 

Could you connect MISO to MOSI (default P0.11 and P0.12) and see if it echo'es back the byte in the terminal?

 

Kind regards,

Håkon

[Linus]

That was the first thing I tried. When that didn't work, I hooked up an oscilloscope and noticed that all the SPI pins are silent.

[Håkon Alseth]

That is strange. You haven't changed the SPI pins right? If so, you might have to clean your build folder, then re-import / run cmake again.

Could you see if its still silent using this hex? merged.hex

 

Note: it only sends one byte every sec, and CSN + MISO is floating. So, check the MOSI and CLK line if you're going to scope something.

 

Cheers,

Håkon

[Linus]

Thank you for the hex file. It turns out that it works fine with that one. Was that built with the v0.4.0 release?
I'll try to rebuild everything from scratch and see if that helps.

Regards,

Linus

[Håkon Alseth]

Here's my repo's (atleast the one's used in this example):

"nrf" is checked out with tag "v0.4.0"

"zephyr" is checked out with tag "v1.14.99-ncs1"

"nrfxlib" is checked out with tag "v0.4.0"

 

Cheers,

Håkon

[Linus]

I have the same tags in my repos. I have tried to rebuild everything, but the problem remained.

I tried to debug it using 'west debug', but for some reason the code refuses to run in the debugger.

However, using printk() I found out that the SPI pins were not changed, even though the .overlay file in the SPI example was correct. Then I noticed that the symlink 'nrf9160_pca10090_ns.overlay' doesn't match the board name. I renamed it to 'nrf9160_pca10090ns.overlay' and voila! Now it works!

The question now is why it worked for you. Don't you have the same overlays?

Regards,

Linus

[Håkon Alseth]

Hi Linus,

 

This is a very good spot. Thank you very much!

I have no idea how I've managed to make this mistake, or how this sample has even worked at my end!

 

I'll correct it asap.

 

Kind regards,

Håkon