SPI frequency issue on nRF7002 DK

[QuangPhuoc]

Hi there

I'm trying to make the SPI work on nRF53 (My board is nRF7002 DK) refer the tutorial academy.nordicsemi.com/.../ but I had the issue about frequency of spi peripheral.

Specifically:
When I config the the max frequency of SPI equal to 125Khz, I can get the output signal on the logic analyzer

&spi1 {

    compatible = "nordic,nrf-spim";

    status = "okay";

    pinctrl-0 = <&spi1_default>;

    pinctrl-1 = <&spi1_sleep>;

    pinctrl-names = "default", "sleep";

    cs-gpios = <&gpio0 25 GPIO_ACTIVE_LOW>;

    max-frequency = <0x7a1200>;

    gendev: gendev@0 {

        compatible = "vnd,spi-device";

        reg = <0>;

        spi-max-frequency = <125000>;  // <= THIS CHANGE

        label = "GenDev";

    };

};

But when I try to change the frequency of SPI to higher, such as 500Khz, 1MHz. Signal on logic analyzer becomes strange (Please refer below picture)

&spi1 {

    compatible = "nordic,nrf-spim";

    status = "okay";

    pinctrl-0 = <&spi1_default>;

    pinctrl-1 = <&spi1_sleep>;

    pinctrl-names = "default", "sleep";

    cs-gpios = <&gpio0 25 GPIO_ACTIVE_LOW>;

    max-frequency = <0x7a1200>;

    gendev: gendev@0 {

        compatible = "vnd,spi-device";

        reg = <0>;

        spi-max-frequency = <1000000>;  // <= THIS CHANGE

        label = "GenDev";

    };

};

I also tried with SPI0-> SPI4 but still get the same issue

Below is the source code I used (I use nRF connect SDK 2.9.0)

SPI-Template.zip

Did I miss anything? Looking forward to your feedback.

Thank you

[Simonr]

Hi

What pins are you using for SPI data pins in your sample here? Note that some of the pins are connected to other function on the DK already. Please use the DK user guide for reference here. 

What kind of SPI device are you trying to communicate with here? And do you see any logging from the application when running this project on your end?

Best regards,

Simon

[QuangPhuoc]

Thank you for reply

1. What pins are you using for SPI data pins in your sample here?

My full device tree:

&spi1 {

    compatible = "nordic,nrf-spim";

    status = "okay";

    pinctrl-0 = <&spi1_default>;

    pinctrl-1 = <&spi1_sleep>;

    pinctrl-names = "default", "sleep";

    cs-gpios = <&gpio0 25 GPIO_ACTIVE_LOW>;

    max-frequency = <0x7a1200>;

    gendev: gendev@0 {

        compatible = "vnd,spi-device";

        reg = <0>;

        spi-max-frequency = <125000>;  // <= THIS CHANGE

        label = "GenDev";

    };

};

&pinctrl {
spi1_default: spi1_default {
group1 {
psels = <NRF_PSEL(SPIM_SCK, 0, 6)>,
<NRF_PSEL(SPIM_MOSI, 0, 7)>,
<NRF_PSEL(SPIM_MISO, 0, 26)>;
};
};
spi1_sleep: spi1_sleep {
group1 {
psels = <NRF_PSEL(SPIM_SCK, 0, 6)>,
<NRF_PSEL(SPIM_MOSI, 0, 7)>,
<NRF_PSEL(SPIM_MISO, 0, 26)>;
low-power-enable;
};
};
};

I got this on the sample refer the SPI tutorial of Nordic https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-5-serial-peripheral-interface-spi/topic/zephyr-spi-api/

You can also check my full code in the attachment

2. Note that some of the pins are connected to other function on the DK already

I'm using nRF7002-DK (PCA10143). I checked this don't use the pin 0.06, 0.07, 0.26 and 0.25.

Below is the detailed image of the board I used.

3. What kind of SPI device are you trying to communicate with here?

That's just a sample. There I try to send SPI signal and read it with logic analyzer.

The problem is when I config the spi-max-frequency = <125000>;, I can capture the signal on logic analyer. But when I changed this to spi-max-frequency = <1000000>;, I just get the CS signal and no MOSI or SCK signal (See the image I attached in the original post)

4. Do you see any logging from the application when running this project on your end?

I don't see any unusual phenomenon on the Log (Use printf). LED flashes normally

You can check the operation on the attachment

If you need more information, please let me know

Have a nice day

[Simonr]

Hi

Just so we're on the same page. The SPI pins aren't connected to anything here, you're just checking with a logic analyzer, correct? Are you certain the analyzer supports higher frequencies?

I don't see this being a problem I'm afraid. If the SPI max frequency is the only thing you changed there shouldn't be any reason for it to not operate. You can try adding some debug logging in your configs and upload the full log here for us to review.

Best regards,

Simon