Running the LSM6DLS (IMU) zephyr example with nrf52840 based Xiao BLE Sense

Hi all,

I've been trying to get the samples/sensor/lsm6dsl example working with the nrf52840-based Xiao BLE Sense and have had no luck.

I guess that it's due to the power line for the sensor being connected to the P1.08

I dug into the xiao_ble_sense.dts and I can indeed see:

	lsm6ds3tr-c-en {
		compatible = "regulator-fixed-sync", "regulator-fixed";
		enable-gpios = <&gpio1 8 (NRF_GPIO_DRIVE_S0H1 | GPIO_ACTIVE_HIGH)>;
		regulator-name = "LSM6DS3TR_C_EN";
		regulator-boot-on;
		startup-delay-us = <3000>;
	};

However no matter how I try and drive it from the code the sensor refuses to initialize with the console output:

[00:00:00.794,647] <dbg> LSM6DSL: lsm6dsl_init_chip: failed to reboot device
[00:00:00.794,677] <err> LSM6DSL: Failed to initialize chip
*** Booting nRF Connect SDK d96769faceca ***
Begin init of lsm6ds3tr and regulator 
sensor: device not ready.

My code to run is based of the sample code for the sensor with the lsm6ds3tr_c_en modifications:

/*
 * Copyright (c) 2018 STMicroelectronics
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/drivers/sensor.h>
#include <stdio.h>
#include <zephyr/sys/util.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/regulator.h>

static const struct device *lsm6ds3tr_c_en;

static inline float out_ev(struct sensor_value *val)
{
	return (val->val1 + (float)val->val2 / 1000000);
}

static int print_samples;
static int lsm6dsl_trig_cnt;

static struct sensor_value accel_x_out, accel_y_out, accel_z_out;
static struct sensor_value gyro_x_out, gyro_y_out, gyro_z_out;
#if defined(CONFIG_LSM6DSL_EXT0_LIS2MDL)
static struct sensor_value magn_x_out, magn_y_out, magn_z_out;
#endif
#if defined(CONFIG_LSM6DSL_EXT0_LPS22HB)
static struct sensor_value press_out, temp_out;
#endif

#ifdef CONFIG_LSM6DSL_TRIGGER
static void lsm6dsl_trigger_handler(const struct device *dev,
				    const struct sensor_trigger *trig)
{
	static struct sensor_value accel_x, accel_y, accel_z;
	static struct sensor_value gyro_x, gyro_y, gyro_z;
#if defined(CONFIG_LSM6DSL_EXT0_LIS2MDL)
	static struct sensor_value magn_x, magn_y, magn_z;
#endif
#if defined(CONFIG_LSM6DSL_EXT0_LPS22HB)
	static struct sensor_value press, temp;
#endif
	lsm6dsl_trig_cnt++;

	sensor_sample_fetch_chan(dev, SENSOR_CHAN_ACCEL_XYZ);
	sensor_channel_get(dev, SENSOR_CHAN_ACCEL_X, &accel_x);
	sensor_channel_get(dev, SENSOR_CHAN_ACCEL_Y, &accel_y);
	sensor_channel_get(dev, SENSOR_CHAN_ACCEL_Z, &accel_z);

	/* lsm6dsl gyro */
	sensor_sample_fetch_chan(dev, SENSOR_CHAN_GYRO_XYZ);
	sensor_channel_get(dev, SENSOR_CHAN_GYRO_X, &gyro_x);
	sensor_channel_get(dev, SENSOR_CHAN_GYRO_Y, &gyro_y);
	sensor_channel_get(dev, SENSOR_CHAN_GYRO_Z, &gyro_z);

#if defined(CONFIG_LSM6DSL_EXT0_LIS2MDL)
	/* lsm6dsl external magn */
	sensor_sample_fetch_chan(dev, SENSOR_CHAN_MAGN_XYZ);
	sensor_channel_get(dev, SENSOR_CHAN_MAGN_X, &magn_x);
	sensor_channel_get(dev, SENSOR_CHAN_MAGN_Y, &magn_y);
	sensor_channel_get(dev, SENSOR_CHAN_MAGN_Z, &magn_z);
#endif

#if defined(CONFIG_LSM6DSL_EXT0_LPS22HB)
	/* lsm6dsl external press/temp */
	sensor_sample_fetch_chan(dev, SENSOR_CHAN_PRESS);
	sensor_channel_get(dev, SENSOR_CHAN_PRESS, &press);

	sensor_sample_fetch_chan(dev, SENSOR_CHAN_AMBIENT_TEMP);
	sensor_channel_get(dev, SENSOR_CHAN_AMBIENT_TEMP, &temp);
#endif

	if (print_samples) {
		print_samples = 0;

		accel_x_out = accel_x;
		accel_y_out = accel_y;
		accel_z_out = accel_z;

		gyro_x_out = gyro_x;
		gyro_y_out = gyro_y;
		gyro_z_out = gyro_z;

#if defined(CONFIG_LSM6DSL_EXT0_LIS2MDL)
		magn_x_out = magn_x;
		magn_y_out = magn_y;
		magn_z_out = magn_z;
#endif

#if defined(CONFIG_LSM6DSL_EXT0_LPS22HB)
		press_out = press;
		temp_out = temp;
#endif
	}

}
#endif

int main(void)
{
	int cnt = 0;
	char out_str[64];
	struct sensor_value odr_attr;
    const struct device *const lsm6dsl_dev = DEVICE_DT_GET_ONE(st_lsm6dsl);

	printk("Begin init of lsm6ds3tr and regulator \n");
    /* Initialize the regulator device */
	lsm6ds3tr_c_en = DEVICE_DT_GET(DT_PATH(lsm6ds3tr_c_en));
    if (!device_is_ready(lsm6ds3tr_c_en)) {
        printk("Regulator device not ready\n");
        return 0;
    }

    /* Enable the regulator */
    if (regulator_enable(lsm6ds3tr_c_en) < 0) {
        printk("Failed to enable regulator\n");
        return 0;
    }

	 k_sleep(K_MSEC(10000));

	
	if (!device_is_ready(lsm6dsl_dev)) {
		printk("sensor: device not ready.\n");
		return 0;
	}

	/* set accel/gyro sampling frequency to 104 Hz */
	odr_attr.val1 = 104;
	odr_attr.val2 = 0;

	if (sensor_attr_set(lsm6dsl_dev, SENSOR_CHAN_ACCEL_XYZ,
			    SENSOR_ATTR_SAMPLING_FREQUENCY, &odr_attr) < 0) {
		printk("Cannot set sampling frequency for accelerometer.\n");
		return 0;
	}

	if (sensor_attr_set(lsm6dsl_dev, SENSOR_CHAN_GYRO_XYZ,
			    SENSOR_ATTR_SAMPLING_FREQUENCY, &odr_attr) < 0) {
		printk("Cannot set sampling frequency for gyro.\n");
		return 0;
	}

#ifdef CONFIG_LSM6DSL_TRIGGER
	struct sensor_trigger trig;

	trig.type = SENSOR_TRIG_DATA_READY;
	trig.chan = SENSOR_CHAN_ACCEL_XYZ;

	if (sensor_trigger_set(lsm6dsl_dev, &trig, lsm6dsl_trigger_handler) != 0) {
		printk("Could not set sensor type and channel\n");
		return 0;
	}
#endif

	if (sensor_sample_fetch(lsm6dsl_dev) < 0) {
		printk("Sensor sample update error\n");
		return 0;
	}

	while (1) {
		/* Erase previous */
		printk("\0033\014");
		printf("LSM6DSL sensor samples:\n\n");

		/* lsm6dsl accel */
		sprintf(out_str, "accel x:%f ms/2 y:%f ms/2 z:%f ms/2",
							  out_ev(&accel_x_out),
							  out_ev(&accel_y_out),
							  out_ev(&accel_z_out));
		printk("%s\n", out_str);

		/* lsm6dsl gyro */
		sprintf(out_str, "gyro x:%f dps y:%f dps z:%f dps",
							   out_ev(&gyro_x_out),
							   out_ev(&gyro_y_out),
							   out_ev(&gyro_z_out));
		printk("%s\n", out_str);

#if defined(CONFIG_LSM6DSL_EXT0_LIS2MDL)
		/* lsm6dsl external magn */
		sprintf(out_str, "magn x:%f gauss y:%f gauss z:%f gauss",
							   out_ev(&magn_x_out),
							   out_ev(&magn_y_out),
							   out_ev(&magn_z_out));
		printk("%s\n", out_str);
#endif

#if defined(CONFIG_LSM6DSL_EXT0_LPS22HB)
		/* lsm6dsl external press/temp */
		sprintf(out_str, "press: %f kPa - temp: %f deg",
			out_ev(&press_out), out_ev(&temp_out));
		printk("%s\n", out_str);
#endif

		printk("loop:%d trig_cnt:%d\n\n", ++cnt, lsm6dsl_trig_cnt);

		print_samples = 1;
		k_sleep(K_MSEC(2000));
	}
}


And my prj.conf:
CONFIG_STDOUT_CONSOLE=y
CONFIG_I2C=y
CONFIG_SPI=n
CONFIG_SENSOR=y
CONFIG_LSM6DSL_TRIGGER_GLOBAL_THREAD=y
CONFIG_CBPRINTF_FP_SUPPORT=y

CONFIG_LOG=y
CONFIG_LOG_DEFAULT_LEVEL=3
CONFIG_SENSOR_LOG_LEVEL_DBG=y

CONFIG_UART_CONSOLE=y
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_UART_LINE_CTRL=y

I am trying to drive this the proper way but am I missing something obvious?

Should I just ignore the config and drive P1.08 manually?

Thanks for taking a look!
I'm using nRF Connect SDK v2.6.0 (latest available at the time of posting)

Parents
  • After much confusion and life interruptions it would seem that I do have this working, via the LSM6DSL sample out of the box, or so I think.

    I was having much trouble with different things, in one case the app would crash without writing to the UART unless I stepped through the initialization with the debugger, in another case it would not flash due to some obscure overflow error.

    So, maybe this is all just a figment of my imagination.

    My setup is:
    - running within a Docker image
    - using VSCode via its remote container connected to the Docker image
    - nRFConnect VSCode extension
    - Xiao board on a Seeed Xiao expansion board
    - Uploading via Segger J-Link EDU
    - On Linux

    At the time of the above weirdness I had changed the nrfConnect tools version number, for some silly reason, from 2.5.2 to 2.6.0.
    I don't know if that's when things fell apart or not. But, I did hear on a webcast today that the presenter was having some issues with the later 2.6.0 version of the tools, so perhaps it did have some impact??

    At the same time I was trying to implement a version of LSM6DS3 as seen here: https://iwasz.pl/electronics/2021-06-18-out-of-tree-zephyr-module.md/     Got nowhere except the above debug problem.

    Then I changed the nRFConnect tool version back to 2.5.2 and went way for a few days, then things started working, don't ask why though. (Perhaps the local total eclipse fixed it)

    The versions I believe I'm currently using, and were I found the version info:

    Seeed Xiao bootloader: (double click Xiao reset button)
    ------------------------
    UF2 Bootloader 0.6.1 lib/nrfx (v2.0.0) lib/tinyusb (0.10.1-293-gaf8e5a90) lib/uf2 (remotes/origin/configupdate-9-gadbb8c7)
    Model: Seeed XIAO nRF52840
    Board-ID: Seeed_XIAO_nRF52840_Sense
    SoftDevice: S140 version 7.3.0
    Date: Nov 12 2021

    OS/SDKs
    ----------
    Zephyr
    --------
    source: github.com/.../sdk-zephyr
    3.4.99.0 (VERSION file) A Nordic downstream version I'm pretty sure
    git HEAD: 2e2523efe52a7ac89f0567b8798fd857b1e71ae3"


    nRF Connect SDK
    ----------------
    source: github.com/.../sdk-nrf
    2.5.0 (VERSION file)
    git HEAD: 1fae141fc6713dd331b797fc96c90dc84552242d

    nRFX Common Libraries (nRFxlib)
    ---------------------------------
    github.com/.../sdk-nrfxlib
    2.5.0 (.git/FETCH_HEAD)
    git HEAD: 78cc07ed7c9f168c3d6316db5af969ac5f7c977a

    nRF Tool Chain
    ---------------
    loaded via VSCode nRFConnect extension
    nRFConnect SDK ToolChain: 2.5.20231017.513615545433 (From build output)


    Versions reported from build output:
    ------------------------------------------
    -- CMake version: 3.20.5
    -- Using NCS Toolchain 2.5.20231017.513615545433 for building.
    -- Found Python3: ~/ncs/toolchains/7795df4459/usr/local/bin/python3 (found suitable version "3.8.2")
    -- Found west (found suitable version "1.1.0")
    -- Board: xiao_ble_sense
    -- Found host-tools: zephyr 0.16.1 (~/ncs/toolchains/7795df4459/opt/zephyr-sdk)
    -- Found toolchain: zephyr 0.16.1 (~/ncs/toolchains/7795df4459/opt/zephyr-sdk)
    -- Found Dtc: ~/ncs/toolchains/7795df4459/usr/local/bin/dtc (found suitable version "1.4.7", minimum required is "1.4.6")
    -- Found BOARD.dts: ~/ncs/v2.5.0/zephyr/boards/arm/xiao_ble/xiao_ble_sense.dts
    -- The C compiler identification is GNU 12.2.0
    -- The CXX compiler identification is GNU 12.2.0
    -- The ASM compiler identification is GNU
    -- Found assembler: ~/ncs/toolchains/7795df4459/opt/zephyr-sdk/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc
    -- Zephyr version: 3.4.99 (~/ncs/v2.5.0/zephyr), build: 2e2523efe52a

    I suppose when the moon comes around again it will fall apart again...

  • Thank you for your input !

    This is wild, what do you think is causing this shaky operation?

    Oh and I also followed the out of tree zephyr module repo but then I realized that all that changes is the I2C address and that is defined in the configuration in the recent versions of Zephyr.

Reply Children
  • no clue as to why the issues were happening. I could not narrow it down via the debugger.  Just starting under the debugger did not help, I needed to step through the init code, stepping over most of the secondary function calls before I could let it run.

    I did try changing the tools version back to the 2.6.0, it still works. 

    I did setup to  run west build/flash within a terminal outside of VSCode/nRFConnect by setting appropriate env variables. So I suppose I could have had something wonky there, part built with 2.6 tools, part with 2.5 tools. 

    I suppose it could be a non initialized variable somewhere, or a strange timing issue.

      I think I prefer the eclipse clearing thing out as the resolution. :o)

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