Simple SPI

[verulia]

Hello,

I am using nrf9160 and want to test the just simple SPI function. The code that I found from github(https://github.com/Rallare/fw-nrfconnect-nrf/tree/nrf9160_samples/samples/nrf9160/spi c) is old and gives me too many errors. Are there any simple SPI code that I can try in my nrf9160 board in order to test whether I can send a simple data via SPI. I also found spi_flash_at45 however I don't have any device from at45 family to test it so another simple example would be so helpful for me. 

Thank you

[Håkon Alseth]

Hi,

 

Generic test code for nRF5340 can be found here:

https://devzone.nordicsemi.com/f/nordic-q-a/67065/how-to-configure-and-setup-an-spi-device-to-nrf5340/276687

 

I added some small modifications to the above sample, as SPI0 is shared with UART0/TWIM0 etc on nRF9160:

4520.simple_spi_test_nrf9160.zip

 

Kind regards,

Håkon

[verulia]

Hi,

Thank you for the fast reply. I just ran the code however I am always receiving 0 in the RX_recv. Shouldn't the value in RX_recv be similar with TX_sent since this code is just tries to send a value and receive it back as far as I understood? I didn't make any change in the code yet.

Q2:

I want to send data from nrf9160 to an external device, in order to just make a simple test before implementing a flash driver, I want to test the pins and spi, for that I am using scana to check the signals coming from spi ports. My question here is that how can I send my data to scana rather than making a loopback. For instance first I have to ad a chip select for scana, adding ss=<13> to the overlay file can be the first step right? What should I change other than this?

Thank you

[Håkon Alseth]

Hi,

 

verulia said:

I can loopback which means spi is working but I can't see any signals from scana.

So, when sending x, you receive x back as well? Then it seems that there's something wrong with your logic analyzer setup. Check the GND connection.

 

verulia said:

Also, if I wan't to change this gpio pin setting should I use gpio_pin_configure?

Yes, you can use that to configure any unused GPIO if you'd like.

 

Kind regards,

Håkon 

[verulia]

Hi,

I tested the logic analyzer for testing other gpio pins and it working however I still can't see any signal from spi code. GND is connected and I can't see clock,miso and mosi. I reverse the pins for mosi and clk however I am always getting 1(high) from <10> port. I also tried to decrease the sampling rate but still I am always getting hi from <10> port even though the GND is not connected. I should be able to directly observe the clk signal from logic analyzer right without changing anything in the code? 

Thank you

[Håkon Alseth]

The sample doesn't send all the time (once per second), are you sure you're triggering on the correct channel, with the correct edge triggering?

[verulia]

I didn't do any triggering, I just connected one port to the ground and other port to clk output. As trial I triggered the output channel of clk port both risinf and falling but result didn't change. 

[verulia]

Hello,

I think I misunderstood the switching part because I just try to switch the pins of mosi and clk in the overlay file by just writing mosi<10> clk<11> however this doesn't work. How can I switch them what is the right way?

Thank you

[Håkon Alseth]

You can use another gpio by setting the .overlay file.

For instance:

&spi3 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	sck-pin = <x>;
	mosi-pin = <y>;
	miso-pin = <z>;
};

 

Where x, y, z are a valid and unused gpio. If it doesn't switch the gpios, try deleting your build folder and re-importing the project.

 

Kind regards,

Håkon

[verulia]

Hi Hakan,

The pins are changed no problem in that part rigth now but still I can't see the rigth signal in the logic analyzer. I adjusted edge triggering with rising edge( also tried with falling and all other triggering options) I see that clk signal seems always high. Not 0-1-0-1 its always one.I played with sampling frequency but it also didn't change the result. I tested the logic analyzer with different chip and I saw 1-0-1-0 clk signal so logic analyzer is working fine. I didn't change the code that you sent me and it is doing loopback so no problem in spi functionality. Then what should I do in this case? I just want to see the clk signal and mosi in this case I thought that just attaching the logic analyzer to those output pins was sufficient to see the outputs am I missing something in this point?

Thank you

[verulia]

Hi, I couldn't get an answer for my last reply do you have any idea of what can I also try?

Thank for the help so much

[Håkon Alseth]

Hi,

 

On the UART terminal (serial terminal), are you getting the expected output when connecting MISO to MOSI using a patch wire?

ie: 

TX sent: X

RX recv: X

 

BR,

Håkon

[verulia]

Hi,

Yes when I connect miso to mosi with a wire I receive the same value. I also changed the gpio pins for clk and miso it also works fine when I change them I can still see the outputs on lte link monitor. The only problem is I cant even see the clk ouput 1-0-1-0 on logic analyzer, I also cant see mosi. The clk pin always gives 1 in logic analyzer but it should be 0-1-0-1. I changed the sampling rate, frequenct however still result is same. I didn't understand what I am missing. Should I have to make additional changes in the code or should I need to do some adjustments in the logic analyzer. But in logic analyzer when I just send 1-0-1-0 from gpio pins(different from spi pins) I was be able to see the output clearly without doing any modification

Thank you