Interfacing IMU Sensor (LSM6DSL) with SPI

[Thanuha]

Hi

I am using nrf52840dk- nrf52840 board to interface the IMU Sensor using SPI instead of I2C using nrf connect sdk for vs code.
But I am facing error.

Below I have attached the overlay file I created for LSM6DSL. I haven't changed anything in the main.c and I didn't changed anything in the prj.confg file also.

In the main.c there is if loop

if (!device_is_ready(lsm6dsl_dev)) {

        printk("sensor: device not ready.\n");

        return;

    }

When I buid my code and try to debug the code it is coming into this if loop showing device is not ready. Can Someone help me with this.

Note:I didn't changed anything in the main.c

       

&qspi {

    status = "disabled";

};

&pinctrl {

    spi1_default: spi1_default {

        group1 {

            psels = <NRF_PSEL(SPIM_SCK, 1, 3)>,

                <NRF_PSEL(SPIM_MOSI, 1, 2)>,

                <NRF_PSEL(SPIM_MISO, 1, 5)>;

        };

    };

    spi1_sleep: spi1_sleep {

        group1 {

            psels = <NRF_PSEL(SPIM_SCK, 1, 3)>,

                <NRF_PSEL(SPIM_MOSI, 1, 2)>,

                <NRF_PSEL(SPIM_MISO, 1, 5)>;

            low-power-enable;

        };

    };

};

&spi1 {

    compatible = "nordic,nrf-spi";

    status = "okay";

    pinctrl-0 = <&spi1_default>;

    pinctrl-1 = <&spi1_sleep>;

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

    cs-gpios = <&gpio1 4 GPIO_ACTIVE_LOW>;

    lsm6dsl1: lsm6dsl@0{

        compatible = "st,lsm6dsl";

        reg = <0x0>;

        spi-max-frequency =<100000>;

        label ="lsm6dsl";

    };

};

In the above overlay file I added a node for lsm6dsl1 with st,lsm6dsl compatible.

[nordicator_prim3]

There are only a few things that would cause this. Either the initialization function in the driver for LSM6DSL is failing (it would print an error) or the device information can not be found in the device tree.

Looking at the driver in "..\ncs\v2.0.0\zephyr\drivers\sensor\lsm6dsl\lsm6dsl.c", if the initialization fails you will see one of two possible errors:

1. LOG_ERR("Failed to initialize sensor bus");

2. LOG_ERR("Failed to initialize chip");

So if you have logging enabled and odn't see either of these errors then the driver can't find the device information from the device tree. How are you getting the variable "lsm6dsl_dev"?

[Thanuha]

that is already there in the example code i am not changing in the example code i am just adding the overlay file which I shared above

[nordicator_prim3]

OK,

The only other thing I can think of is changing the frequency. The data sheet says the minimum spi clock time is 100ns (10MHz). In your overlay, it is set to only 100KHz. Try changing it to "spi-max-frequency =<10000000>;".

[stc114533]

Have you solved it? I also did the same thing as you did and I encountered the same problem, it'd be great if you can guide me to make it work. I'm also using the sample code, so it's probably my overlay that causes this issue.

[stc114533]

So I printed out the log messages, found that it's because I didn't set the irq-gpios in overlay. Now everything works as expected.

st_lsm6dsl: &spi3 {

compatible = "nordic,nrf-spim";

status = "okay";

pinctrl-0 = <&spi3_default>;

pinctrl-1 = <&spi3_sleep>;

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

cs-gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;

lsm6dsl: lsm6dsl@0 {

compatible = "st,lsm6dsl";

status = "okay";

spi-max-frequency = <10000000>;

reg = <0>;

irq-gpios = <&gpio0 9 0>;

};

};

[Mindtech]

I have the same problem you described, but with the nRF9160, could you share your complete device tree overlay?

[stc114533]

Sorry for the late reply.

This is everything I have for spi3, hope that helps.

&pinctrl {
    spi3_default: spi3_default {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 3)>,
                    <NRF_PSEL(SPIM_MISO, 0, 5)>,
                    <NRF_PSEL(SPIM_MOSI, 0, 4)>;
        };
    };
    spi3_sleep: spi3_sleep {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 3)>,
                    <NRF_PSEL(SPIM_MISO, 0, 5)>,
                    <NRF_PSEL(SPIM_MOSI, 0, 4)>;
        };
    };
};


st_lsm6dsl: &spi3 {
    compatible = "nordic,nrf-spim";
    status = "okay";
    pinctrl-0 = <&spi3_default>;
    pinctrl-1 = <&spi3_sleep>;
    pinctrl-names = "default", "sleep";
    cs-gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;
    lsm6dsl: lsm6dsl@0 {
        compatible = "st,lsm6dsl";
        status = "okay";
        spi-max-frequency = <10000000>;
        reg = <0>;
        irq-gpios = <&gpio0 9 0>;
    };
};

[Mindtech]

Thanks, it's very similar to my device tree... I believe I'm missing some other detail.

[stc114533]

Have you tried printing the log messages? What did you get?

[Mindtech]

Yes, i got the following answer

"<err> spi_nrfx_spim: Timeout waiting for transfer complete"

I will try to see the signals with a logic analyzer