Bluetooth Mesh Light CTL (color tuned light) sample

[ji_584]

Is there a sample app that uses the Zephyr Light CTL Bluetooth Mesh model?  I've tried to add that model to the light_ctrl sample app, but get a crash during configuration so I must be doing something wrong. 

The onoff_level_lighting_vnd app claims to support that model but it doesn't seem to be using the Zephyr lighting models. 

Thanks

[Hung Bui]

Hi Jack, 
I think you are right. There isn't a sample for that model right now. Please let us know the issue you are seeing we can try to take a look. 
We have limited capacity in the holidays period but will be back to full staff by beginning of the year. 

[ji_584]

Thanks, here goes.

I started with the VSCode plugin light_ctrl sample using version 2.8.0 of the toolchain and libraries. Build machines with Windows and Linux tried.  Target is nRF52840DK. 

The unmodified sample builds, runs, and provisions and functions correctly with the nRF Mesh Android app. 

After the modifications below, the code compiles and runs, but during initialization I get an assert showing on the console (see below), and an "Initial Configuration Failed" message from the app.  

Note that the assert states that temp srv wasn't properly initialized.  On debugging, however, it appeared that the tmp srv model was properly initialized and the light CTL model was not, however I have a low degree of confidence in this assessment. 

model_handler.c was modified from the sample as follows:

Add headers

#include <bluetooth/mesh/light_ctrl_srv.h>
#include <bluetooth/mesh/light_ctl_srv.h>

Add placeholder handlers

static void temp_srv_set(struct bt_mesh_light_temp_srv *srv,
                         struct bt_mesh_msg_ctx *ctx,
                         const struct bt_mesh_light_temp_set *set,
                         struct bt_mesh_light_temp_status *status)
{
    // Implement setting the temperature on your hardware
}

static void temp_srv_get(struct bt_mesh_light_temp_srv *srv,
                         struct bt_mesh_msg_ctx *ctx,
                         struct bt_mesh_light_temp_status *status)
{
    // Implement reading the current temperature state from your hardware
}

static const struct bt_mesh_light_temp_srv_handlers temp_srv_handlers = {

    .set = temp_srv_set,

    .get = temp_srv_get,

};

static struct bt_mesh_light_temp_srv light_temp_srv =

    BT_MESH_LIGHT_TEMP_SRV_INIT(&temp_srv_handlers);

static struct bt_mesh_light_ctl_srv light_ctl_srv =

    BT_MESH_LIGHT_CTL_SRV_INIT(&lightness_srv_handlers, &temp_srv_handlers);

Add light ctl and light temp srv models:

static struct bt_mesh_elem elements[] = {

    BT_MESH_ELEM(1,

                 BT_MESH_MODEL_LIST(

                     BT_MESH_MODEL_CFG_SRV,

                     BT_MESH_MODEL_HEALTH_SRV(&health_srv, &health_pub),

                     BT_MESH_MODEL_LIGHTNESS_SRV(&my_ctx.lightness_srv),

                     BT_MESH_MODEL_SCENE_SRV(&scene_srv),

                     BT_MESH_MODEL_SENSOR_SRV(&sensor_srv),

                     BT_MESH_MODEL_LIGHT_CTL_SRV(&light_ctl_srv)

                                    ),

                 BT_MESH_MODEL_NONE),

    BT_MESH_ELEM(2,

                 BT_MESH_MODEL_LIST(

                     BT_MESH_MODEL_LIGHT_TEMP_SRV(&light_ctl_srv.temp_srv)

                 ),

                 BT_MESH_MODEL_NONE),

    BT_MESH_ELEM(3,

                 BT_MESH_MODEL_LIST(

                     BT_MESH_MODEL_LIGHT_CTRL_SRV(&light_ctrl_srv)

                                   ),

                BT_MESH_MODEL_NONE)

};

prj.conf changes

CONFIG_BT_MESH_MODEL_EXTENSION_LIST_SIZE=33

CONFIG_BT_MESH_LIGHT_CTL_SRV=y

CONFIG_CORTEX_M_DEBUG_MONITOR_HOOK=y

CONFIG_SEGGER_DEBUGMON=y

Console output:

*** Booting Mesh Light Fixture v2.8.0-c57f55d0686e ***
*** Using nRF Connect SDK v2.8.0-a2386bfc8401 ***
*** Using Zephyr OS v3.7.99-0bc3393fb112 ***
Initializing...
[00:00:00.008,941] <inf> fs_nvs: 8 Sectors of 4096 bytes
[00:00:00.008,972] <inf> fs_nvs: alloc wra: 0, fb0
[00:00:00.008,972] <inf> fs_nvs: data wra: 0, 44
[00:00:00.009,124] <inf> bt_sdc_hci_driver: SoftDevice Controller build revision:
fe 2c f9 6a 7f 36 22 2e a0 79 c0 40 be 2c 03 20 |.,.j.6". .y.@.,.
40 c2 f3 32 |@..2
[00:00:00.013,305] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:00.013,336] <inf> bt_hci_core: HW Variant: nRF52x (0x0002)
[00:00:00.013,366] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 254.63788 Build 573996906
[00:00:00.013,763] <inf> bt_hci_core: No ID address. App must call settings_load()
Bluetooth initialized
[00:00:00.439,453] <inf> bt_hci_core: Identity: EC:2C:E8:3F:5C:0E (random)
[00:00:00.439,514] <inf> bt_hci_core: HCI: version 6.0 (0x0e) revision 0x104e, manufacturer 0x0059
[00:00:00.439,544] <inf> bt_hci_core: LMP: version 6.0 (0x0e) subver 0x104e
[00:00:00.442,474] <inf> bt_mesh_provisionee: Device UUID: 5c0b7b01-159d-4da6-a3f4-84feea62c259
Mesh initialized
Successfully enabled LC server
[00:02:35.433,380] <inf> bt_mesh_main: Primary Element: 0x0020
New light transition-> Lvl: 0, Time: 0, Delay: 0
[00:02:35.443,359] <err> bt_mesh_light_ctl_srv: Light CTL srv[32]: Temp. srv not properly initialized
ASSERTION FAIL @ WEST_TOPDIR/zephyr/kernel/work.c:687
[00:02:35.443,878] <err> os: r0/a1: 0x00000004 r1/a2: 0x000002af r2/a3: 0x00000003
[00:02:35.443,908] <err> os: r3/a4: 0x00000004 r12/ip: 0x0001b4a4 r14/lr: 0x0004443b
[00:02:35.443,908] <err> os: xpsr: 0x01000000
[00:02:35.443,939] <err> os: s[ 0]: 0x00000000 s[ 1]: 0x0004c9d3 s[ 2]: 0x00000000 s[ 3]: 0x00000000
[00:02:35.443,969] <err> os: s[ 4]: 0x0005e348 s[ 5]: 0x2000dd34 s[ 6]: 0x00000000 s[ 7]: 0x0004bc3d
[00:02:35.443,969] <err> os: s[ 8]: 0x20006ea8 s[ 9]: 0x0004bc7f s[10]: 0xffffffff s[11]: 0x2000dd34
[00:02:35.444,030] <err> os: s[12]: 0x00000000 s[13]: 0x00044431 s[14]: 0x0005e348 s[15]: 0x00066cdc
[00:02:35.444,030] <err> os: fpscr: 0x000002af
[00:02:35.444,030] <err> os: Faulting instruction address (r15/pc): 0x0004bc6a
[00:02:35.444,091] <err> os: >>> ZEPHYR FATAL ERROR 4: Kernel panic on CPU 0
[00:02:35.444,122] <err> os: Current thread: 0x20006ea8 (sysworkq)
[00:00:00.000,427] <err> qspi_nor: JEDEC id [ff ff ff] expect [c2 28 17]



[ji_584]

Hi,
It's been a while for this ticket, let me know if I need to open a new one.

I have recently renewed effort in this area, and I have been unable to get a client to actually set the temperature.  I used the example ctl srv app posted above: 
https://github.com/omkar3141/sdk-nrf/blob/5c2911b2970616609d03437c1992d311f3f302e7/samples/bluetooth/mesh/light_ctrl/src/model_handler.c

and the dimmer example app modified to include a ctl client.

I provisioned with the Android nRF Mesh, setting the app key for the relevant models on both server and client, and publish address of 0xFFFF on the client side models.   No error messages are observed, the client appears to be responding to the button press with calls to bt_mesh_light_ctl_set_unack(), the lightness level changes on the server, but there is no indication that the temp level changes.  I had to fix a few config file errors due to changing API requirements.  Hardware is two nrf54l15dk.

Any advice on getting this working?

Thanks,
Jack

Here is the model_handler.c I tested, derived from the sample dimmer app:

/*
* Copyright (c) 2023 Nordic Semiconductor ASA
*
* SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
*/

/**
* @file
* @brief Model handler for the Light Dimmer Controller.
*
*/
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/mesh/proxy.h>
#include <bluetooth/mesh/models.h>
#include <bluetooth/mesh/light_ctl_cli.h>
#include <dk_buttons_and_leds.h>
#include "model_handler.h"
#include <time.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(dimmer_sample, LOG_LEVEL_INF);

#define SHORT_PRESS_THRESHOLD_MS 300
#define LONG_PRESS_TIMEOUT_SEC K_SECONDS(20)
#define DELTA_MOVE_STEP 1000
#define SCENE_COUNT 4

/* Color temperature mapping constants */
#define CTL_TEMP_MIN 2700 /* Warm white at low lightness */
#define CTL_TEMP_MAX 6500 /* Cool white at high lightness */
#define CTL_DELTA_UV 0 /* No delta UV adjustment */

enum dim_direction { DIM_DOWN, DIM_UP };

/* Forward declarations */
static void ctl_status_handler(struct bt_mesh_light_ctl_cli *cli,
struct bt_mesh_msg_ctx *ctx,
const struct bt_mesh_light_ctl_status *status);
static void temp_status_handler(struct bt_mesh_light_ctl_cli *cli,
struct bt_mesh_msg_ctx *ctx,
const struct bt_mesh_light_temp_status *status);

/* CTL client handlers */
static const struct bt_mesh_light_ctl_cli_handlers ctl_handlers = {
.ctl_status = ctl_status_handler,
.temp_status = temp_status_handler,
};

/** Context for a single Light Dimmer instance. */
struct dimmer_ctx {
/** Generic OnOff client instance for this switch */
struct bt_mesh_onoff_cli onoff_client;
/** Generic Level client instance for this switch */
struct bt_mesh_lvl_cli lvl_client;
/** Light CTL client instance for this switch */
struct bt_mesh_light_ctl_cli ctl_client;
/* Relative start time of the latest press of the button */
int64_t press_start_time;
/* Dimmer direction */
enum dim_direction direction;
/* Long press work (Dimmer mode) */
struct k_work_delayable long_press_start_work;
struct k_work_delayable long_press_stop_work;
/* Current lightness level for temperature mapping */
uint16_t current_lightness;
};

/** Context for a single scene button instance */
struct scene_btn_ctx {
/** Scene client instance for this button */
struct bt_mesh_scene_cli client;
/** The currently recalled scene*/
uint16_t current_scene;
/** Time when button was pressed */
int64_t press_start_time;
};

#if IS_ENABLED(CONFIG_BT_MESH_NLC_PERF_CONF)
static const uint8_t cmp2_elem_offset[1] = { 0 };

static const struct bt_mesh_comp2_record comp_rec[2] = {
{/* Basic Scene Selector NLC Profile 1.0.1*/
.id = BT_MESH_NLC_PROFILE_ID_BASIC_SCENE_SELECTOR,
.version.x = 1,
.version.y = 0,
.version.z = 1,
.elem_offset_cnt = 1,
.elem_offset = cmp2_elem_offset,
.data_len = 0
},
{/* Dimming Control NLC Profile 1.0.1 */
.id = BT_MESH_NLC_PROFILE_ID_DIMMING_CONTROL,
.version.x = 1,
.version.y = 0,
.version.z = 1,
.elem_offset_cnt = 1,
.elem_offset = cmp2_elem_offset,
.data_len = 0
}
};

static const struct bt_mesh_comp2 comp_p2 = {
.record_cnt = 2,
.record = comp_rec
};
#endif

static void dimmer_start(struct k_work *work)
{
struct dimmer_ctx *ctx = CONTAINER_OF(k_work_delayable_from_work(work), struct dimmer_ctx,
long_press_start_work);

struct bt_mesh_lvl_move_set move_set = {
.delta = (ctx->direction == DIM_UP) ? DELTA_MOVE_STEP :
(int16_t)(-1 * DELTA_MOVE_STEP),
.transition = &(struct bt_mesh_model_transition){ .time = 500 },
};

LOG_INF("Start dimming %s...", (ctx->direction == DIM_UP ? "UP" : "DOWN"));

/* Use traditional level control for continuous dimming - CTL will be set on release */
if (bt_mesh_model_pub_is_unicast(ctx->lvl_client.model)) {
bt_mesh_lvl_cli_move_set(&ctx->lvl_client, NULL, &move_set, NULL);
} else {
bt_mesh_lvl_cli_move_set_unack(&ctx->lvl_client, NULL, &move_set);
}

k_work_reschedule(&ctx->long_press_stop_work, LONG_PRESS_TIMEOUT_SEC);
}

static void dimmer_stop(struct k_work *work)
{
struct dimmer_ctx *ctx = CONTAINER_OF(k_work_delayable_from_work(work), struct dimmer_ctx,
long_press_stop_work);

struct bt_mesh_lvl_move_set move_set = {
.delta = 0,
.transition = NULL,
};

if (bt_mesh_model_pub_is_unicast(ctx->lvl_client.model)) {
bt_mesh_lvl_cli_move_set(&ctx->lvl_client, NULL, &move_set, NULL);
} else {
bt_mesh_lvl_cli_move_set_unack(&ctx->lvl_client, NULL, &move_set);
}
}

static struct dimmer_ctx dimmer = {
.lvl_client = BT_MESH_LVL_CLI_INIT(NULL),
.onoff_client = BT_MESH_ONOFF_CLI_INIT(NULL),
.ctl_client = BT_MESH_LIGHT_CTL_CLI_INIT(&ctl_handlers),
.press_start_time = 0,
.direction = DIM_DOWN,
.current_lightness = 0
};

/* Helper function to map lightness level to color temperature */
static uint16_t lightness_to_temperature(uint16_t lightness)
{
/* Linear mapping: 0 lightness = 2700K, 65535 lightness = 6500K */
uint32_t temp_range = CTL_TEMP_MAX - CTL_TEMP_MIN;
uint32_t temp = CTL_TEMP_MIN + ((uint32_t)lightness * temp_range) / 65535;
return (uint16_t)temp;
}

/* Helper function to set both lightness and temperature */
static int set_light_ctl(uint16_t lightness, const struct bt_mesh_model_transition *transition)
{
uint16_t temperature = lightness_to_temperature(lightness);

struct bt_mesh_light_ctl_set set = {
.params = {
.light = lightness,
.temp = temperature,
.delta_uv = CTL_DELTA_UV,
},
.transition = transition
};

dimmer.current_lightness = lightness;

LOG_INF("Setting CTL: lightness=%u, temp=%uK, delta_uv=%d", lightness, temperature, CTL_DELTA_UV);

/* Use unacknowledged message for group addresses or to avoid blocking */
return bt_mesh_light_ctl_set_unack(&dimmer.ctl_client, NULL, &set);
}

/* CTL status handlers */
static void ctl_status_handler(struct bt_mesh_light_ctl_cli *cli,
struct bt_mesh_msg_ctx *ctx,
const struct bt_mesh_light_ctl_status *status)
{
LOG_INF("CTL status: light=%u, temp=%u", status->current_light, status->current_temp);
dimmer.current_lightness = status->current_light;
}

static void temp_status_handler(struct bt_mesh_light_ctl_cli *cli,
struct bt_mesh_msg_ctx *ctx,
const struct bt_mesh_light_temp_status *status)
{
LOG_INF("CTL temp status: temp=%u, delta_uv=%d",
status->current.temp, status->current.delta_uv);
}

static void dimmer_button_handler(struct dimmer_ctx *ctx, bool pressed)
{
int err;

if (pressed) {
ctx->direction = (ctx->direction == DIM_UP) ? DIM_DOWN : DIM_UP;

ctx->press_start_time = k_uptime_get();
err = k_work_reschedule(&ctx->long_press_start_work,
K_MSEC(SHORT_PRESS_THRESHOLD_MS));

if (err < 0) {
LOG_ERR("Scheduling dimming to start failed: %d", err);
}
} else {
if ((k_uptime_get() - ctx->press_start_time) >= SHORT_PRESS_THRESHOLD_MS) {
/** Button was released after a long time.
* Stop dimming immediately.
*/
err = k_work_reschedule(&ctx->long_press_stop_work, K_NO_WAIT);

if (err < 0) {
LOG_INF("Scheduling dimming to stop failed: %d", err);
}

} else {
/** Button was released after a short time.
* Cancel dimming operation and toggle light on/off with CTL.
*/
k_work_cancel_delayable(&ctx->long_press_start_work);

uint16_t target_lightness = (ctx->direction == DIM_UP) ? 65535 : 0;
LOG_INF("Toggle light %s with CTL (lightness=%u)",
(ctx->direction == DIM_UP ? "ON" : "OFF"), target_lightness);

err = set_light_ctl(target_lightness, NULL);
if (err) {
LOG_ERR("Failed to send CTL set message: %d", err);

/* Fallback to basic on/off control */
struct bt_mesh_onoff_set set = {
.on_off = ctx->direction,
};

if (bt_mesh_model_pub_is_unicast(ctx->onoff_client.model)) {
err = bt_mesh_onoff_cli_set(&ctx->onoff_client, NULL, &set, NULL);
} else {
err = bt_mesh_onoff_cli_set_unack(&ctx->onoff_client, NULL, &set);
}

if (err) {
LOG_ERR("Failed to send OnOff fallback message: %d", err);
}
}
}
}
}

static struct scene_btn_ctx scene_btn = {
.current_scene = 1,
.press_start_time = 0
};

static void scene_button_handler(struct scene_btn_ctx *ctx, bool pressed)
{
if (pressed) {
ctx->press_start_time = k_uptime_get();
} else {
int err;

if (k_uptime_get() - ctx->press_start_time > SHORT_PRESS_THRESHOLD_MS) {
/* Long press, store scene */
LOG_INF("Storing scene %d", ctx->current_scene);
err = bt_mesh_scene_cli_store_unack(&ctx->client, NULL,
ctx->current_scene);

if (err) {
LOG_ERR("Failed to send Scene Store message: %d", err);
}
} else {
/* Short press, recall next scene */
ctx->current_scene = (ctx->current_scene >= SCENE_COUNT) ?
1 : ctx->current_scene + 1;
LOG_INF("Recalling scene %d", ctx->current_scene);
err = bt_mesh_scene_cli_recall_unack(&ctx->client, NULL,
ctx->current_scene, NULL);

if (err) {
LOG_ERR("Failed to send Scene Recall message: %d", err);
}
}
}
}

static void button_handler_cb(uint32_t pressed, uint32_t changed)
{
if (!bt_mesh_is_provisioned()) {
LOG_ERR("Node is not provisioned");
return;
}

if (changed & BIT(0)) {
dimmer_button_handler(&dimmer, pressed & BIT(0));
}
if (changed & BIT(1)) {
scene_button_handler(&scene_btn, pressed & BIT(1));
}
}

/* Set up a repeating delayed work to blink the DK's LEDs when attention is
* requested.
*/
static struct k_work_delayable attention_blink_work;
static bool attention;

static void attention_blink(struct k_work *work)
{
static int idx;
const uint8_t pattern[] = {
#if DT_NODE_EXISTS(DT_ALIAS(sw0))
BIT(0),
#endif
#if DT_NODE_EXISTS(DT_ALIAS(sw1))
BIT(1),
#endif
#if DT_NODE_EXISTS(DT_ALIAS(sw2))
BIT(2),
#endif
#if DT_NODE_EXISTS(DT_ALIAS(sw3))
BIT(3),
#endif
};

if (attention) {
dk_set_leds(pattern[idx++ % ARRAY_SIZE(pattern)]);
k_work_reschedule(&attention_blink_work, K_MSEC(30));
} else {
dk_set_leds(DK_NO_LEDS_MSK);
}
}

static void attention_on(const struct bt_mesh_model *mod)
{
attention = true;
k_work_reschedule(&attention_blink_work, K_NO_WAIT);
}

static void attention_off(const struct bt_mesh_model *mod)
{
/* Will stop rescheduling blink timer */
attention = false;
}

static const struct bt_mesh_health_srv_cb health_srv_cb = {
.attn_on = attention_on,
.attn_off = attention_off,
};

static struct bt_mesh_health_srv health_srv = {
.cb = &health_srv_cb,
};

BT_MESH_HEALTH_PUB_DEFINE(health_pub, 0);

static struct bt_mesh_elem elements[] = {
BT_MESH_ELEM(1,
BT_MESH_MODEL_LIST(BT_MESH_MODEL_CFG_SRV,
BT_MESH_MODEL_HEALTH_SRV(&health_srv, &health_pub),
BT_MESH_MODEL_ONOFF_CLI(&dimmer.onoff_client),
BT_MESH_MODEL_LVL_CLI(&dimmer.lvl_client),
BT_MESH_MODEL_LIGHT_CTL_CLI(&dimmer.ctl_client),
BT_MESH_MODEL_SCENE_CLI(&scene_btn.client)),
BT_MESH_MODEL_NONE),
};

static const struct bt_mesh_comp comp = {
.cid = CONFIG_BT_COMPANY_ID,
.elem = elements,
.elem_count = ARRAY_SIZE(elements),
};

const struct bt_mesh_comp *model_handler_init(void)
{
#if IS_ENABLED(CONFIG_BT_MESH_NLC_PERF_CONF)
if (bt_mesh_comp2_register(&comp_p2)) {
printf("Failed to register comp2\n");
}
#endif

static struct button_handler button_handler = {
.cb = button_handler_cb,
};

dk_button_handler_add(&button_handler);
k_work_init_delayable(&attention_blink_work, attention_blink);
k_work_init_delayable(&dimmer.long_press_start_work, dimmer_start);
k_work_init_delayable(&dimmer.long_press_stop_work, dimmer_stop);

return &comp;
}

[Elfving]

Hi Jack, 

That's okay, we can keep it here.

I'll look into it, but I might have to get back to you on this next week.

Regards,

Elfving

[Elfving]

Hi again, and thanks for the patience on this one.

I bet the issue is related to how you are addressing the light fixture, and the fact that Light CTL happens to be on another element than the ones related to lightness on the light fixture node. I haven't gotten around to get properly tested yet, but I figured it was better to get to you on this sooner rather than even later. Your code looks ok.

I realize it's been a while since you asked. Any update on this one from your side? How are you configuring the addressing?

Regards,

Elfving

[ji_584]

Funny you should post this, last night it started working and I was puzzled as to why.

I had originally been using no subscription address for the servers and 0xFFFF (all nodes) publish address for the clients. Recently, I switched from the Android app to iOS, which is much easier to configure, and I used a group for both publish and subscribe.  It seems that CTL started to work when configured this way.

So my conclusion is that something in the CTL server and client doesn't work with 0xFFFF addresses.  I don't know if the issue is that the CTL client won't send to all nodes, or if the CTL server doesn't respond to those messages.

Would you expect all of the servers to work when an appropriate client message is sent to 0xFFFF even if no subscribe address is set on the server?

This is great progress.

Thanks,

Jack

[Elfving]

ji_584 said:

I had originally been using no subscription address for the servers and 0xFFFF (all nodes) publish address for the clients. Recently, I switched from the Android app to iOS, which is much easier to configure, and I used a group for both publish and subscribe.  It seems that CTL started to work when configured this way.

That does make some sense; the address of the node is its primary/first element address. So I wonder if the 0xFFFF address wouldn't target secondary elements. I typically use group addresses for quick tests like these.

For this reason 0xFFFF is eg. not recommended for a DFU. I've handled a case where that was a problem before.

ji_584 said:

Would you expect all of the servers to work when an appropriate client message is sent to 0xFFFF even if no subscribe address is set on the server?

Yeah, I believe that is generally true: the node doesn't need to subscribe to anything to receive a message to 0xFFFF, though once again: that might just be the primary element. 

Regards,

Elfving

[ji_584]

Ok, so that mystery is solved thank you!.  I'm still doing some testing, will let you know when I close it out.

Jack

[Elfving]

Sounds good! Feel free to open more cases here as well if anything pops-up.

Regards,

Elfving