Cannot get Zigbee to work on a nRF52840 board

[EnricoBilla]

Hi all, I've recently got a custom nRF52840 board (in particular this Makerdiary nRF52840 MDK USB Dongle).

I got it to try and experiment with the Zigbee protocol, so I just tried to run the template example. Since it's my first time with Zephyr I had many problems just to get it to compile, but after fixing some reference to leds in the code, and adding some lines to the overlay file I got it to compile successfully.

The problem is that I always get a kernel panic, bus fault or something along those lines. The funny thing is that the error changes a lot, and it's almost always never the same.
I tried to figure out what the problem is, so my workflow has been like this: get the program counter address when the fault happened (from the UART log), find the line it corresponds in the code with addr2line and try to analyse the code that had a fault.

Sadly I could not find the common cause of all those errors, but (I think) they are all around the multithreading library (k_thread, nrf_rtc_timer, cpu_idle, etc...) and all of them are triggered only if I uncomment the zigbee_enable() line at the end of main.

Here is the code for completeness:

main.c:

/*
 * Copyright (c) 2021 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
 */

/** @file
 *
 * @brief Zigbee application template.
 */

#include <zephyr.h>
#include <logging/log.h>
#include <dk_buttons_and_leds.h>

#include <zboss_api.h>
#include <zigbee/zigbee_error_handler.h>
#include <zigbee/zigbee_app_utils.h>
#include <zb_nrf_platform.h>


/* Device endpoint, used to receive ZCL commands. */
#define APP_TEMPLATE_ENDPOINT               10

/* Type of power sources available for the device.
 * For possible values see section 3.2.2.2.8 of ZCL specification.
 */
#define TEMPLATE_INIT_BASIC_POWER_SOURCE    ZB_ZCL_BASIC_POWER_SOURCE_DC_SOURCE

/* LED indicating that device successfully joined Zigbee network. */
#define ZIGBEE_NETWORK_STATE_LED            DK_LED2

/* LED used for device identification. */
#define IDENTIFY_LED                        DK_LED3

/* Button used to enter the Identify mode. */
#define IDENTIFY_MODE_BUTTON                DK_BTN4_MSK

/* Button to start Factory Reset */
#define FACTORY_RESET_BUTTON                IDENTIFY_MODE_BUTTON

LOG_MODULE_REGISTER(app, LOG_LEVEL_DBG);

/* Main application customizable context.
 * Stores all settings and static values.
 */
struct zb_device_ctx {
	zb_zcl_basic_attrs_t basic_attr;
	zb_zcl_identify_attrs_t identify_attr;
};

/* Zigbee device application context storage. */
static struct zb_device_ctx dev_ctx;

ZB_ZCL_DECLARE_IDENTIFY_ATTRIB_LIST(
	identify_attr_list,
	&dev_ctx.identify_attr.identify_time);

ZB_ZCL_DECLARE_BASIC_ATTRIB_LIST(
	basic_attr_list,
	&dev_ctx.basic_attr.zcl_version,
	&dev_ctx.basic_attr.power_source);

ZB_HA_DECLARE_RANGE_EXTENDER_CLUSTER_LIST(
	app_template_clusters,
	basic_attr_list,
	identify_attr_list);

ZB_HA_DECLARE_RANGE_EXTENDER_EP(
	app_template_ep,
	APP_TEMPLATE_ENDPOINT,
	app_template_clusters);

ZBOSS_DECLARE_DEVICE_CTX_1_EP(
	app_template_ctx,
	app_template_ep);


/**@brief Function for initializing all clusters attributes. */
static void app_clusters_attr_init(void)
{
	/* Basic cluster attributes data */
	dev_ctx.basic_attr.zcl_version = ZB_ZCL_VERSION;
	dev_ctx.basic_attr.power_source = TEMPLATE_INIT_BASIC_POWER_SOURCE;

	/* Identify cluster attributes data. */
	dev_ctx.identify_attr.identify_time =
		ZB_ZCL_IDENTIFY_IDENTIFY_TIME_DEFAULT_VALUE;
}

/**@brief Function to toggle the identify LED
 *
 * @param  bufid  Unused parameter, required by ZBOSS scheduler API.
 */
static void toggle_identify_led(zb_bufid_t bufid)
{
	static int blink_status;

	dk_set_led(IDENTIFY_LED, (++blink_status) % 2);
	ZB_SCHEDULE_APP_ALARM(toggle_identify_led, bufid, ZB_MILLISECONDS_TO_BEACON_INTERVAL(100));
}

/**@brief Function to handle identify notification events on the first endpoint.
 *
 * @param  bufid  Unused parameter, required by ZBOSS scheduler API.
 */
static void identify_cb(zb_bufid_t bufid)
{
	zb_ret_t zb_err_code;

	if (bufid) {
		/* Schedule a self-scheduling function that will toggle the LED */
		ZB_SCHEDULE_APP_CALLBACK(toggle_identify_led, bufid);
	} else {
		/* Cancel the toggling function alarm and turn off LED */
		zb_err_code = ZB_SCHEDULE_APP_ALARM_CANCEL(toggle_identify_led, ZB_ALARM_ANY_PARAM);
		ZVUNUSED(zb_err_code);

		dk_set_led(IDENTIFY_LED, 0);
	}
}

/**@breif Starts identifying the device.
 *
 * @param  bufid  Unused parameter, required by ZBOSS scheduler API.
 */
static void start_identifying(zb_bufid_t bufid)
{
	zb_ret_t zb_err_code;

	ZVUNUSED(bufid);

	if (ZB_JOINED()) {
		/* Check if endpoint is in identifying mode,
		 * if not put desired endpoint in identifying mode.
		 */
		if (dev_ctx.identify_attr.identify_time ==
		ZB_ZCL_IDENTIFY_IDENTIFY_TIME_DEFAULT_VALUE) {
			LOG_INF("Enter identify mode");
			zb_err_code = zb_bdb_finding_binding_target(
				APP_TEMPLATE_ENDPOINT);
			ZB_ERROR_CHECK(zb_err_code);
		} else {
			LOG_INF("Cancel identify mode");
			zb_bdb_finding_binding_target_cancel();
		}
	} else {
		LOG_WRN("Device not in a network - cannot enter identify mode");
	}
}

/**@brief Callback for button events.
 *
 * @param[in]   button_state  Bitmask containing buttons state.
 * @param[in]   has_changed   Bitmask containing buttons
 *                            that have changed their state.
 */
static void button_changed(uint32_t button_state, uint32_t has_changed)
{
	if (IDENTIFY_MODE_BUTTON & has_changed) {
		if (IDENTIFY_MODE_BUTTON & button_state) {
			/* Button changed its state to pressed */
		} else {
			/* Button changed its state to released */
			if (was_factory_reset_done()) {
				/* The long press was for Factory Reset */
				LOG_DBG("After Factory Reset - ignore button release");
			} else   {
				/* Button released before Factory Reset */

				/* Start identification mode */
				ZB_SCHEDULE_APP_CALLBACK(start_identifying, 0);
			}
		}
	}

	check_factory_reset_button(button_state, has_changed);
}

/**@brief Function for initializing LEDs and Buttons. */
static void configure_gpio(void)
{
	int err;

	err = dk_buttons_init(button_changed);
	if (err) {
		LOG_ERR("Cannot init buttons (err: %d)", err);
	}

	err = dk_leds_init();
	if (err) {
		LOG_ERR("Cannot init LEDs (err: %d)", err);
	}
}

/**@brief Zigbee stack event handler.
 *
 * @param[in]   bufid   Reference to the Zigbee stack buffer
 *                      used to pass signal.
 */
void zboss_signal_handler(zb_bufid_t bufid)
{
	/* Update network status LED. */
	zigbee_led_status_update(bufid, ZIGBEE_NETWORK_STATE_LED);

	/* No application-specific behavior is required.
	 * Call default signal handler.
	 */
	ZB_ERROR_CHECK(zigbee_default_signal_handler(bufid));

	/* All callbacks should either reuse or free passed buffers.
	 * If bufid == 0, the buffer is invalid (not passed).
	 */
	if (bufid) {
		zb_buf_free(bufid);
	}
}

void main(void)
{
	LOG_INF("Starting Zigbee application template example");

	/* Initialize */
	configure_gpio();
	register_factory_reset_button(FACTORY_RESET_BUTTON);

	/* Register device context (endpoints). */
	ZB_AF_REGISTER_DEVICE_CTX(&app_template_ctx);

	app_clusters_attr_init();

	/* Register handlers to identify notifications */
	ZB_AF_SET_IDENTIFY_NOTIFICATION_HANDLER(APP_TEMPLATE_ENDPOINT, identify_cb);

	/* Start Zigbee default thread */
	zigbee_enable(); // this is the line that crashes

	LOG_INF("Zigbee application template started");
}

nrf52840_mdk_usb_dongle.dts:

/*
 * Copyright (c) 2022 Nikola Trifunovic
 * Copyright (c) 2018 Nordic Semiconductor ASA
 * Copyright (c) 2017 Linaro Limited
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/dts-v1/;
#include <nordic/nrf52840_qiaa.dtsi>
#include "nrf52840_mdk_usb_dongle-pinctrl.dtsi"

/ {
	model = "nRF52840 MDK USB Dongle";
	compatible = "nrf52840_mdk_usb_dongle";

	chosen {
		zephyr,console = &uart0;
		zephyr,shell-uart = &uart0;
		zephyr,uart-mcumgr = &uart0;
		zephyr,bt-mon-uart = &uart0;
		zephyr,bt-c2h-uart = &uart0;
		zephyr,sram = &sram0;
		zephyr,flash = &flash0;
		zephyr,code-partition = &slot0_partition;
	};

	leds {
		compatible = "gpio-leds";
		led0_red: led_0 {
			gpios = <&gpio0 23 GPIO_ACTIVE_LOW>;
			label = "Red LED 0";
			status = "okay";
		};
		led0_green: led_1 {
			gpios = <&gpio0 22 GPIO_ACTIVE_LOW>;
			label = "Green LED 0";
		};
		led0_blue: led_2 {
			gpios = <&gpio0 24 GPIO_ACTIVE_LOW>;
			label = "Blue LED 0";
		};
	};

	pwmleds {
		compatible = "pwm-leds";
		red_pwm_led: pwm_led_0 {
			pwms = <&pwm0 23>;
		};
		green_pwm_led: pwm_led_1 {
			pwms = <&pwm0 22>;
		};
		blue_pwm_led: pwm_led_2 {
			pwms = <&pwm0 24>;
		};
	};

	buttons {
		compatible = "gpio-keys";
		reset_button: button_0 {
			gpios = <&gpio0 18 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "reset button";
		};
	};

	/* These aliases are provided for compatibility with samples */
	aliases {
		led0 = &led0_red;
		led1 = &led0_green;
		led2 = &led0_blue;
		led0-red   = &led0_red;
		led0-green = &led0_green;
		led0-blue  = &led0_blue;
		pwm-led0 = &red_pwm_led;
		pwm-led1 = &green_pwm_led;
		pwm-led2 = &blue_pwm_led;
		red-pwm-led = &red_pwm_led;
		green-pwm-led = &green_pwm_led;
		blue-pwm-led = &blue_pwm_led;
	};
};

&gpiote {
	status = "okay";
};

&gpio0 {
	status = "okay";
};

&gpio1 {
	status = "okay";
};

&adc {
	status = "okay";
	
};

&uart0 {
	compatible = "nordic,nrf-uarte";
	status = "okay";
	current-speed = <115200>;
	pinctrl-0 = <&uart0_default>;
	pinctrl-1 = <&uart0_sleep>;
	pinctrl-names = "default", "sleep";
};

&pwm0 {
	status = "okay";
};

/* Include flash partition table.
 * Two partition tables are available:
 * fstab-stock		-compatible with Nordic nRF5 bootloader, default
 * fstab-debugger	-to use an external debugger, w/o the nRF5 bootloader
 */
#include "fstab-stock.dts"

zephyr_udc0: &usbd {
	compatible = "nordic,nrf-usbd";
	status = "okay";
};

nrf52840_mdk_usb_dongle.overlay:

/ {
    chosen {
        zephyr,entropy = &rng;
    };
};

&pwm0 {
    status = "okay";
};

prj.conf:

CONFIG_LOG=y
CONFIG_ASSERT=n
CONFIG_HW_STACK_PROTECTION=y

CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_SERIAL=y
CONFIG_GPIO=y

# Make sure printk is not printing to the UART console
CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y

CONFIG_HEAP_MEM_POOL_SIZE=2048
CONFIG_MAIN_THREAD_PRIORITY=7

CONFIG_ZIGBEE=y
CONFIG_ZIGBEE_APP_UTILS=y
CONFIG_ZIGBEE_ROLE_ROUTER=y

# Enable DK LED and Buttons library
CONFIG_DK_LIBRARY=y

# This example requires more workqueue stack
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

# Enable nRF ECB driver
CONFIG_CRYPTO=y
CONFIG_CRYPTO_NRF_ECB=y
CONFIG_CRYPTO_INIT_PRIORITY=80

# Cryptocell is not supported through CSPRNG driver API: NCSDK-4813
CONFIG_ENTROPY_CC3XX=n

# Networking
CONFIG_NET_IPV6_MLD=n
CONFIG_NET_IPV6_NBR_CACHE=n
CONFIG_NET_IPV6_RA_RDNSS=n
CONFIG_NET_IP_ADDR_CHECK=n
CONFIG_NET_UDP=n

Here is one example or error I'm getting (from UART):

*** Booting Zephyr OS build v2.7.99-ncs1-2212-g038a2de883a0  ***
[00:00:00.000,793] <inf> ieee802154_nrf5: nRF5 802154 radio initialized
[00:00:00.017,517] <inf> app: Starting Zigbee application template example
[00:00:00.017,944] <inf> app: Zigbee application template started
[00:00:00.018,218] <err> os: ***** BUS FAULT *****
[00:00:00.018,218] <err> os:   Imprecise data bus error
[00:00:00.018,249] <err> os: r0/a1:  0x00007dc8  r1/a2:  0xffffffff  r2/a3:  0x00000000
[00:00:00.018,249] <err> os: r3/a4:  0x00007dc8 r12/ip:  0x00000000 r14/lr:  0x0000b297
[00:00:00.018,280] <err> os:  xpsr:  0x61000000
[00:00:00.018,280] <err> os: s[ 0]:  0x00000000  s[ 1]:  0x00000000  s[ 2]:  0x00000000  s[ 3]:  0x00000000
[00:00:00.018,310] <err> os: s[ 4]:  0x00000000  s[ 5]:  0x00000000  s[ 6]:  0x00000000  s[ 7]:  0x00000000
[00:00:00.018,310] <err> os: s[ 8]:  0x00000000  s[ 9]:  0xffffffff  s[10]:  0x00000000  s[11]:  0xffffffff
[00:00:00.018,341] <err> os: s[12]:  0x00000000  s[13]:  0xffffffff  s[14]:  0x00000000  s[15]:  0x00000000
[00:00:00.018,341] <err> os: fpscr:  0x8df21a22
[00:00:00.018,341] <err> os: Faulting instruction address (r15/pc): 0x00019226
[00:00:00.018,402] <err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0
[00:00:00.018,402] <err> os: Current thread: 0x200022b0 (unknown)
[00:00:00.143,432] <err> fatal_error: Resetting system

Note that PC 0x00019226 corresponds to zephyr/kernel/timeout.c:81

Here is another:

*** Booting Zephyr OS build v2.7.99-ncs1-2212-g038a2de883a0  ***
[00:00:00.000,793] <inf> ieee802154_nrf5: nRF5 802154 radio initialized
[00:00:00.017,578] <inf> app: Starting Zigbee application template example
[00:00:00.018,005] <inf> app: Zigbee application template started
[00:00:00.018,280] <err> os: ***** BUS FAULT *****
[00:00:00.018,280] <err> os:   Imprecise data bus error
[00:00:00.018,310] <err> os: r0/a1:  0x00007dc6  r1/a2:  0xffffffff  r2/a3:  0x00000000
[00:00:00.018,341] <err> os: r3/a4:  0x00007dc6 r12/ip:  0x00000000 r14/lr:  0x0000b297
[00:00:00.018,341] <err> os:  xpsr:  0x61000000
[00:00:00.018,341] <err> os: s[ 0]:  0x00000000  s[ 1]:  0x00000000  s[ 2]:  0x00000000  s[ 3]:  0x00000000
[00:00:00.018,371] <err> os: s[ 4]:  0x00000000  s[ 5]:  0x00000000  s[ 6]:  0x00000000  s[ 7]:  0xffffffff
[00:00:00.018,371] <err> os: s[ 8]:  0x00000000  s[ 9]:  0xffffffff  s[10]:  0x00000000  s[11]:  0xffffffff
[00:00:00.018,402] <err> os: s[12]:  0x00000000  s[13]:  0x00000000  s[14]:  0x00000000  s[15]:  0xffffffff
[00:00:00.018,402] <err> os: fpscr:  0x0ac0caaf
[00:00:00.018,432] <err> os: Faulting instruction address (r15/pc): 0x000487dc
[00:00:00.018,463] <err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0
[00:00:00.018,493] <err> os: Current thread: 0x200022b0 (unknown)
[00:00:00.143,432] <err> fatal_error: Resetting system

Here 0x000487dc corresponds to zephyr/include/arch/arm/aarch32/asm_inline_gcc.h:95

Everything in the code is almost identical to the one in the examples, but there has been nothing that made it work someway.

So I'm here to ask you if there is anything I could try to make it work.
Thanks in advance to anyone willing to help me 😄

[EnricoBilla]

I'm updating my own question because I finally got it to work, and the reason why it didn't work was just the bootloader.
I've never thought of that because other programs I wrote were just running fine with the bootloader, so it wasn't an obvious reason for it to not work. Anyway I solved by flashing the .hex directly on flash instead of on top of the bootloader (I was using OpenBootloader).

I'm leaving this here for anybody that will happen to find this thread in the future

[sdalu]

Where did you get the zigbee stack ?

[EnricoBilla]

I was using the official nRF Connect SDK from Nordic since the board was a nRF52840