SPI communication with Lis3dh sensor (nrfConnect SDK)

[Guillaume]

Hello,

I'm encountering an issue while configuring the SPI bus to communicate with a LIS3DH sensor using nrf52832. I'm working with Visual Studio Code using nrfConnect SDK (Zephyr).

Here's the Device Tree Source (DTS):

// Copyright (c) 2024 Nordic Semiconductor ASA

// SPDX-License-Identifier: Apache-2.0

/dts-v1/;

#include <nordic/nrf52832_qfaa.dtsi>

/ {

    model = "xxx";

    compatible = "xxx";

    aliases {

        led0 = &led0;

        led1 = &led1;

        led2 = &led2;

    };

    chosen {

        zephyr,sram = &sram0;

        zephyr,flash = &flash0;

        zephyr,code-partition = &slot0_partition;

    };

    leds{

        compatible = "gpio-leds";

        led0: led_0{

            gpios = <&gpio0 10 GPIO_ACTIVE_LOW>;

            label = "Blue LED 0";

        };

        led1: led_1{

            gpios = <&gpio0 9 GPIO_ACTIVE_LOW>;

            label = "Green LED 1";

        };

        led2: led_2{

            gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;

            label = "Red LED 2";

        };

    };

};

&flash0 {

    partitions {

        compatible = "fixed-partitions";

        #address-cells = <1>;

        #size-cells = <1>;

        boot_partition: partition@0 {

            label = "mcuboot";

            reg = <0x0 0xc000>;

        };

        slot0_partition: partition@c000 {

            label = "image-0";

            reg = <0xc000 0x32000>;

        };

        slot1_partition: partition@3e000 {

            label = "image-1";

            reg = <0x3e000 0x32000>;

        };

        scratch_partition: partition@70000 {

            label = "image-scratch";

            reg = <0x70000 0xa000>;

        };

        storage_partition: partition@7a000 {

            label = "storage";

            reg = <0x7a000 0x6000>;

        };

    };

};

&gpio0 {

    status = "okay";

};

&gpiote {

    status = "okay";

};

lis3dh_spi_master: &spi0 {

    compatible = "nordic,nrf-spi";

    status = "okay";

    pinctrl-0 = <&spi0_default>;

    pinctrl-1 = <&spi0_sleep>;

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

    cs-gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;

   

    reg_lis3dh: lis3dh@0{

        compatible = "st,lis2dh";

        reg = <0>;

        irq-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>, <&gpio0 17 GPIO_ACTIVE_HIGH>;

        spi-max-frequency = <8000000>;

    };

};

&pinctrl {

    spi0_default: spi0_default {

        group1 {

            psels = <NRF_PSEL(SPIM_SCK, 0, 15)>,

                    <NRF_PSEL(SPIM_MOSI, 0, 20)>,

                    <NRF_PSEL(SPIM_MISO, 0, 19)>;

        };

    };

    spi0_sleep: spi0_sleep {

        group1 {

            psels = <NRF_PSEL(SPIM_SCK, 0, 15)>,

                    <NRF_PSEL(SPIM_MOSI, 0, 20)>,

                    <NRF_PSEL(SPIM_MISO, 0, 19)>;

            low-power-enable;

        };  

    };

};

The spi_file is : 

#include <zephyr/kernel.h>

#include <zephyr/device.h>

#include <zephyr/devicetree.h>

#include <zephyr/drivers/gpio.h>

#include <zephyr/drivers/spi.h>

#define LIS3DH_OUT_X_L                  0x28

#define LIS3DH_OUT_X_H                  0x29

#define LIS3DH_SPI_MASTER DT_NODELABEL(lis3dh_spi_master)

// SPI master functionality

const struct device *spi_dev;

struct spi_cs_control spim_cs = {

    .gpio = SPI_CS_GPIOS_DT_SPEC_GET(DT_NODELABEL(reg_lis3dh)),

    .delay = 0,

};

static const struct spi_config spi_cfg = {

    .operation = SPI_OP_MODE_MASTER | SPI_WORD_SET(8) | SPI_TRANSFER_MSB,

    .frequency = 8000000,

    .slave = 0,

    .cs = &spim_cs,

};

void spi_init(void)

{

    spi_dev = DEVICE_DT_GET(LIS3DH_SPI_MASTER);

    if(!device_is_ready(spi_dev)) {

        printk("SPI master device not ready!\n");

    }

    if(!device_is_ready(spim_cs.gpio.port)){

        printk("SPI master chip select device not ready!\n");

    }

}

uint8_t test_spi(void)

{

    int err;

    static uint8_t tx_buf[1];

    static uint8_t rx_buf[1];

    const struct spi_buf_set tx = {

        .buffers = &tx_buf,

        .count = 1

    };

    const struct spi_buf_set rx = {

        .buffers = &rx_buf,

        .count = 1

    };

    tx_buf[0] = LIS3DH_OUT_X_L;

    err = spi_transceive(spi_dev, &spi_cfg, &tx, &rx);

    if (err < 0) {

        printk("spi_transceive_dt() failed, err: %d", err);

        return err;

    }

    printk("\nTx data : %d, Tx data : %d",tx_buf[0], rx_buf[0]);

}

And the main calls spi_init() and test_spi().

I'm encountering this error during spi_transceive() function :

Bluetooth initialized
Advertising successfully started
BEACON START
[00:00:01.005,676] <err> os: ***** Reserved Exception ( -16) *****
[00:00:01.005,706] <err> os: r0/a1: 0x20006f00 r1/a2: 0x00016a0d r2/a3: 0x0002e2bf
[00:00:01.005,706] <err> os: r3/a4: 0x000169f9 r12/ip: 0x000169f9 r14/lr: 0x000169f9
[00:00:01.005,737] <err> os: xpsr: 0x00000000
[00:00:01.005,737] <err> os: s[ 0]: 0x00000000 s[ 1]: 0x00000000 s[ 2]: 0x00000000 s[ 3]: 0x00016c09
[00:00:01.005,767] <err> os: s[ 4]: 0x000169f9 s[ 5]: 0x00000000 s[ 6]: 0x00016b69 s[ 7]: 0x000169f9
[00:00:01.005,767] <err> os: s[ 8]: 0x00016f15 s[ 9]: 0x00031ed3 s[10]: 0x00016f15 s[11]: 0x00016f15
[00:00:01.005,798] <err> os: s[12]: 0x00016f15 s[13]: 0x00016f15 s[14]: 0x00016f15 s[15]: 0x00016f15
[00:00:01.005,798] <err> os: fpscr: 0x00031e89
[00:00:01.005,798] <err> os: Faulting instruction address (r15/pc): 0x000169f9
[00:00:01.005,859] <err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0
[00:00:01.005,889] <err> os: Current thread: 0x20003030 (unknown)
[00:00:01.391,052] <err> fatal_error: Resetting system

Thank for you help

[Guillaume]

Hello, 

Thanks, i don't have issue for the compilation with this code:

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/devicetree.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/spi.h>

/* 1000 msec = 1 sec */
#define SLEEP_TIME_MS   1000

#define LIS3DH_OUT_X_L                  0x28
#define LIS3DH_OUT_X_H                  0x29

#define MY_SPI_MASTER DT_NODELABEL(lis3dh_spi_master)
#define MY_SPI_MASTER_CS_DT_SPEC SPI_CS_GPIOS_DT_SPEC_GET(DT_NODELABEL(reg_lis3dh_master))

// SPI master functionality
const struct device *spi_dev;
static struct k_poll_signal spi_done_sig = K_POLL_SIGNAL_INITIALIZER(spi_done_sig);

static void spi_init(void)
{
    spi_dev = DEVICE_DT_GET(MY_SPI_MASTER);
    if(!device_is_ready(spi_dev)) {
        printk("SPI master device not ready!\n");
    }
    struct gpio_dt_spec spim_cs_gpio = MY_SPI_MASTER_CS_DT_SPEC;
    if(!device_is_ready(spim_cs_gpio.port)){
        printk("SPI master chip select device not ready!\n");
    }
}

static struct spi_config spi_cfg = {
    .operation = SPI_WORD_SET(8) | SPI_TRANSFER_MSB | SPI_MODE_CPOL | SPI_MODE_CPHA,
    .frequency = 8000000,
    .slave = 0,
    .cs = {.gpio = MY_SPI_MASTER_CS_DT_SPEC, .delay = 0},
};

static int spi_write_test_msg(void)
{
    static uint8_t counter = 0;
    static uint8_t tx_buffer[2];
    static uint8_t rx_buffer[2];

    const struct spi_buf tx_buf = {
        .buf = tx_buffer,
        .len = sizeof(tx_buffer)
    };
    const struct spi_buf_set tx = {
        .buffers = &tx_buf,
        .count = 1
    };

    struct spi_buf rx_buf = {
        .buf = rx_buffer,
        .len = sizeof(rx_buffer),
    };
    const struct spi_buf_set rx = {
        .buffers = &rx_buf,
        .count = 1
    };

    // Update the TX buffer with a rolling counter
    tx_buffer[0] = LIS3DH_OUT_X_L;
    printk("SPI TX: 0x%.2x, 0x%.2x\n", tx_buffer[0], tx_buffer[1]);

    // Reset signal
    k_poll_signal_reset(&spi_done_sig);
   
    // Start transaction
    int error = spi_transceive_signal(spi_dev, &spi_cfg, &tx, &rx, &spi_done_sig);
    if(error != 0){
        printk("SPI transceive error: %i\n", error);
        return error;
    }

    // Wait for the done signal to be raised and log the rx buffer
    int spi_signaled, spi_result;
    do{
        k_poll_signal_check(&spi_done_sig, &spi_signaled, &spi_result);
    } while(spi_signaled == 0);
    printk("SPI RX: 0x%.2x, 0x%.2x\n", rx_buffer[0], rx_buffer[1]);
    return 0;
}


int test_spi(void)
{
    int ret;

    spi_init();

    printk("\n SPI master example started\n");

        while (1) {
        spi_write_test_msg();
        if (ret < 0) {
            return 0;
        }
        k_msleep(SLEEP_TIME_MS);
    }

    return 0;
}

But I only received 0xFF on the RX SPI buffer. 

My tag works with nrf5_sdk with Segger and we would like to use Visual Studio Code to use Edge Impulse. (i need to get the accelerometer data to feed the ML.)

I don't see anything with the PicoScope. Do you have some idea ? The DTS seem good ... 

Best regards, 

EDIT by Helsing: Embedding code using Insert->Code for readability.

[helsing]

Hi Guillaume,

Guillaume said:

I don't see anything with the PicoScope.

Are you not seeing any communication at all?

Would you be alble to share the .dts file? Or a snippet of your code demonstrating this?

Best regards,

Håkon

[Guillaume]

Hi Helsing, 

Yes of course. Here the .dts file : 

// Copyright (c) 2024 Nordic Semiconductor ASA
// SPDX-License-Identifier: Apache-2.0

/dts-v1/;
#include <nordic/nrf52832_qfaa.dtsi>

/ {
	model = "xxx";
	compatible = "xxx,xxx";

	aliases {
		led0 = &led0;
		led1 = &led1;
		led2 = &led2;
	};

	chosen {
		zephyr,sram = &sram0;
		zephyr,flash = &flash0;
		zephyr,code-partition = &slot0_partition;
	};

	leds{
		compatible = "gpio-leds"; 
		led0: led_0{
			gpios = <&gpio0 10 GPIO_ACTIVE_LOW>;
			label = "Blue LED 0"; 
	    };
		led1: led_1{
			gpios = <&gpio0 9 GPIO_ACTIVE_LOW>;
			label = "Green LED 1"; 
	    };
		led2: led_2{
			gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;
			label = "Red LED 2"; 
	    };
	};
};

&flash0 {
	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x0 0xc000>;
		};
		slot0_partition: partition@c000 {
			label = "image-0";
			reg = <0xc000 0x32000>;
		};
		slot1_partition: partition@3e000 {
			label = "image-1";
			reg = <0x3e000 0x32000>;
		};
		scratch_partition: partition@70000 {
			label = "image-scratch";
			reg = <0x70000 0xa000>;
		};
		storage_partition: partition@7a000 {
			label = "storage";
			reg = <0x7a000 0x6000>;
		};
	};
};


&gpio0 {
	status = "okay";
};

&gpiote {
    status = "okay";
};


&pinctrl {
	spi_master_default: spi_master_default {
		group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 15)>,
					<NRF_PSEL(SPIM_MOSI, 0, 20)>,
					<NRF_PSEL(SPIM_MISO, 0, 19)>;
		};
	};

	spi_master_sleep: spi_master_sleep {
		group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 15)>,
					<NRF_PSEL(SPIM_MOSI, 0, 20)>,
					<NRF_PSEL(SPIM_MISO, 0, 19)>;
			low-power-enable;
		};
	};
};

lis3dh_spi_master: &spi1 {
	compatible = "nordic,nrf-spi";
    status = "okay";
	pinctrl-0 = <&spi_master_default>;
	pinctrl-1 = <&spi_master_sleep>;
    pinctrl-names = "default","sleep";
    cs-gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;
    
    reg_lis3dh_master: lis3dh@0{
        compatible = "st,lis2dh";
        reg = <0>;
        irq-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>, <&gpio0 17 GPIO_ACTIVE_HIGH>;
        spi-max-frequency = <4000000>;
    };
};

And here the spi file : 

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/devicetree.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/spi.h>

/* 1000 msec = 1 sec */
#define SLEEP_TIME_MS   1000

#define LIS3DH_OUT_X_L                  0x28
#define LIS3DH_OUT_X_H                  0x29

#define MY_SPI_MASTER DT_NODELABEL(lis3dh_spi_master)
#define MY_SPI_MASTER_CS_DT_SPEC SPI_CS_GPIOS_DT_SPEC_GET(DT_NODELABEL(reg_lis3dh_master))

// SPI master functionality
const struct device *spi_dev;
static struct k_poll_signal spi_done_sig = K_POLL_SIGNAL_INITIALIZER(spi_done_sig);

static void spi_init(void)
{
	spi_dev = DEVICE_DT_GET(MY_SPI_MASTER);
	if(!device_is_ready(spi_dev)) {
		printk("SPI master device not ready!\n");
	}
	struct gpio_dt_spec spim_cs_gpio = MY_SPI_MASTER_CS_DT_SPEC;
	if(!device_is_ready(spim_cs_gpio.port)){
		printk("SPI master chip select device not ready!\n");
	}
}

static struct spi_config spi_cfg = {
	.operation = SPI_WORD_SET(8) | SPI_TRANSFER_MSB | SPI_MODE_CPOL | SPI_MODE_CPHA,
	.frequency = 8000000,
	.slave = 0,
	.cs = {.gpio = MY_SPI_MASTER_CS_DT_SPEC, .delay = 0},
};

static int spi_write_test_msg(void)
{
	static uint8_t counter = 0;
	static uint8_t tx_buffer[2];
	static uint8_t rx_buffer[2];

	const struct spi_buf tx_buf = {
		.buf = tx_buffer,
		.len = sizeof(tx_buffer)
	};
	const struct spi_buf_set tx = {
		.buffers = &tx_buf,
		.count = 1
	};

	struct spi_buf rx_buf = {
		.buf = rx_buffer,
		.len = sizeof(rx_buffer),
	};
	const struct spi_buf_set rx = {
		.buffers = &rx_buf,
		.count = 1
	};

	// Update the TX buffer with a rolling counter
	tx_buffer[0] = LIS3DH_OUT_X_L ;
	printk("SPI TX: 0x%.2x, 0x%.2x\n", tx_buffer[0], tx_buffer[1]);

	// Reset signal
	k_poll_signal_reset(&spi_done_sig);
	
	// Start transaction
	int error = spi_transceive_signal(spi_dev, &spi_cfg, &tx, &rx, &spi_done_sig);
	if(error != 0){
		printk("SPI transceive error: %i\n", error);
		return error;
	}

	// Wait for the done signal to be raised and log the rx buffer
	int spi_signaled, spi_result;
	do{
		k_poll_signal_check(&spi_done_sig, &spi_signaled, &spi_result);
	} while(spi_signaled == 0);
	printk("SPI RX: 0x%.2x, 0x%.2x\n", rx_buffer[0], rx_buffer[1]);
	return 0;
}


int test_spi(void)
{
	int ret;

	spi_init();

	printk("\n SPI master example started\n");

		while (1) {
		spi_write_test_msg();
		if (ret < 0) {
			return 0;
		}
		k_msleep(SLEEP_TIME_MS);
	}

	return 0;
}

For information, I'm using Nrf52832, with lis3dh on SPI communication. It works on SDK5.

Guillaume

[helsing]

Hi Guillaume, here are some things to try:

• The frequency in spi_cfg is set to 8000000 (8 MHz), whereas in the device tree it is set to 4000000 (4 MHz) in the spi-max-frequency for the lis3dh@0 node. Try to make these two match and see if it improves anything.
• Check the return value of spi_transceive(): The spi_transceive() function returns a negative error code if there's a problem with the SPI transfer. You can check this return value to get more information about the error.
• Could you try to set the PicoScope to analog and record the output from the SPI pins? Are you not seeing any signals changing/toggeling at all?
• Ensure the SPI driver for NRF52832 is enabled in your prj.conf file with CONFIG_SPI=y.

Which nRF Connect SDK version are you using?