HOW TO define myself model , for example i want to control a RGB light , not only have on/off state ?

[ycp]

1.do I need to write a XX_client.c and XX_server.c myself ? is there a basic model that I can build on it ?

2.I need myself model to send a custom message, how to do that ?

[Biliban Tierli]

Hi ycp,

I am pretty new to the NRF52 ecosystem and so I was wondering the same. After a lot of research and trial & error I found the following:

A model_init_cb function can be specified in the init_params of the mesh_stack_init function. In your model_init_cb function this should be done:

The function that actually adds the model is access_model_add. This function takes two arguments, access_model_add_params_t and access_model_handle_t which is just a uint16_t. Here is a code example of my usecase:

uint16_t model_handle;

access_model_add_params_t add_params =
{
.model_id = ACCESS_MODEL_VENDOR(0xFFAA, 0xF001),  // Format of ACCESS_MODEL_VENDOR is (model_id, company_id)
.element_index = 0, 
.p_opcode_handlers = &m_opcode_handlers[0], 
.opcode_count = ARRAY_SIZE(m_opcode_handlers), 
.p_args = NULL, 
.publish_timeout_cb = publish_interval_cb
};

uint32_t status = access_model_add(&add_params, &model_handle);

Some of the Parameters inside the access_model_add_params_t need some explaining:

- model_id: The Model ID is used for identifying predefined Models, like the Simple_OnOff_Client you are probably using. If you want to make your own you you can choose your own ID and Company value. What I have found is, that the two MSB of these values should be 1 (0xC0 or higher).

- element_index: Defines in which element your model will be imported. Health and Config Server are at index 0.

-  p_opcode_handlers: This contains your OpCodes and should look something like this:

           static const access_opcode_handler_t m_opcode_handlers[] =
           {
                 {ACCESS_OPCODE_VENDOR(0xC1, 0xF001), your_opcode_handler_function},
           };

          // Format of ACCESS_OPCODE_VENDOR is (opcode, company_id)
          // Again what I have found is, that the two MSB of these values should be 1 (0xC0 or higher).

         // Your OpCode Handler Function should look like this:
        // static void your_opcode_handler_function(access_model_handle_t handle, const access_message_rx_t * p_rx_msg, void * p_args);

- p_args: Can be any additional arguments

- publish_timeout_cb: Haven't played around with it yet, currently is just an empty function for me.

After calling access_model_add you should call access_model_subscription_list_alloc, to allow it to subscribe to addresses. If both of these functions return the status 0 (NRF_SUCCESS) your model is added.

To send data you can now use the access_model_publish function. In my example I have it bound to a button in the button event handler. The parameter for the function look like this:

const uint8_t data[] = {0x00};

const access_message_tx_t msg = {
.opcode = ACCESS_OPCODE_VENDOR(0xC2, 0xF001), // Format of ACCESS_OPCODE_VENDOR is (opcode, company_id)
.p_buffer = &data,
.length = ARRAY_SIZE(data),
.force_segmented = false,
.transmic_size = NRF_MESH_TRANSMIC_SIZE_SMALL,
.access_token = nrf_mesh_unique_token_get()
};

access_model_publish(model_handle, &msg);

Here you can now specify your own data. You could make a Structure with all your Data and a Function which converts it to a uint8_t Array, aswel as a function which can then convert it back from a uint8_t Array to your Structure.

For most of the Information I used the Mesh SDK Documentation: www.nordicsemi.com/.../index

I hope this was helpful and if you have any more questions feel free to ask.

Cheers,

Kilian

[ycp]

yes ,it's very helpful ,thank you for shre your experience , but there are still have some detail , i can't figure it out ?

0.I know the model add process basically now , but dont know the detail yet.

1.if we define a  server type compare to  __generic_onoff_server_t

struct __vendor_xx_server_t

{

      /** Model handle assigned to this instance. */
    access_model_handle_t model_handle;

    /** Tid tracker structure. */
    tid_tracker_t tid_tracker;   .........................does this member must include??

    /** Model settings and callbacks for this instance. */
    vendor_xx_server_settings_t settings;  ..........................and this menber

}

and  the client ........................

struct __generic_onoff_client_t
{
    /** Model handle assigned to this instance */
    access_model_handle_t model_handle;

    /** Holds the raw message packet data for transactions */
    generic_onoff_client_msg_data_t msg_pkt; .........................does this member must include??

    /* Acknowledged message context variable */
    access_reliable_t access_message;  ..................I thanke maybe user access_model_reliable_publish more better

    /** Model settings and callbacks for this instance */
    generic_onoff_client_settings_t settings; .........................does this member must include??
};

2.Because i dont know if don't use some parament , does the state will stable , parament  like  transition_time_ms , tid ..., what those parament used for ?

[ycp]

1.yes ,you are right , now i create server_model successfully ,use mesh app can send message ,and it can return some message .

2.but send from a board client_model ,it is failed , but log show it was transmitted .

3. because i have no 2 J-LINK, i can not see the log both , when i drop the J-LINK the board seems can not run. i am so new to nrf52832,maybe i use the wrong way to download the firmware ,can you show me the wright way? thank you. i am use the SEGGER embedded studio IDE .

4.below is my client_model functions , it runs no error but can not transmit message out :

0).................................................client struct..............................................................

struct __custom_model_client
{

    access_model_handle_t model_handle;
    custom_status_cb_t status_cb;
    custom_model_timeout_cb_t timeout_cb;

    struct
    {
        bool reliable_transfer_active;
        uint8_t* data;          
        uint16_t data_lenth;
    } state;

};

1).....................................................init client.....................................................

uint32_t custom_model_client_init(custom_model_client_t * p_client, uint16_t element_index)
{
    uint32_t status;
    if (p_client == NULL ||
        p_client->status_cb == NULL)
    {
        return NRF_ERROR_NULL;
    }

    access_model_add_params_t init_params;
    init_params.model_id.model_id = CUSTOM_MODEL_CLIENT_ID ;
    init_params.model_id.company_id = CUSTOM_MODEL_COMPANY_ID;
    init_params.element_index = element_index;
    init_params.p_opcode_handlers = &m_opcode_handlers[0];
    init_params.opcode_count = sizeof(m_opcode_handlers) / sizeof(m_opcode_handlers[0]);
    init_params.p_args = p_client;
    init_params.publish_timeout_cb = handle_publish_timeout;
    status =  access_model_add(&init_params, &p_client->model_handle);
    
    if (status == NRF_SUCCESS)
    {
        status = access_model_subscription_list_alloc(p_client->model_handle);
    }

    return status;
}

2).....................................................set.....................................................

uint32_t custom_model_client_set(custom_model_client_t * p_client, uint8_t* data , uint16_t length)
{
    uint32_t status;
    if (p_client == NULL || p_client->status_cb == NULL)
    {
        return NRF_ERROR_NULL;
    }
    else if (p_client->state.reliable_transfer_active)
    {
        return NRF_ERROR_INVALID_STATE;
    }
    printf("\n data:%s...lengh:%d \n",data,length);
    if (access_reliable_model_is_free(p_client->model_handle))
    {
        uint32_t status = send_reliable_message(p_client,CUSTOM_MODEL_OPCODE_SET,data,length);
        if (status == NRF_SUCCESS)
        {
            p_client->state.reliable_transfer_active = true;
        }
    }
    else
    {
        printf("[error]model busy ...\n");
        return NRF_ERROR_BUSY;
    }
    printf("%s...status:%d \n",__FUNCTION__,status);
    return status;

}

3).....................................................application demo.....................................................

 {     
                  memset(custom_data,0,sizeof(custom_data));
                  i++;
                  if(i%2==0)
                    {
                      memcpy(custom_data,"led on",strlen("led on"));
                    }
                  else
                    {
                      memcpy(custom_data,"led off",strlen("led off"));
                    }
                  status = access_model_publish_address_set(custom_client.model_handle,publish_address_handle_dev);
                  (void)access_model_reliable_cancel(custom_client.model_handle);
                  custom_model_client_set(&custom_client,custom_data, strlen(custom_data));
                  hal_led_pin_set(BSP_LED_1, (bool)(i&(0x01)));
                  break;
            }

[Biliban Tierli]

Hi,

to program you can simply press the green play-button, as you probably did. To play it safe(and erase provisioning data) you can also do "Target -> Connect J-Link" and then "Target -> Erase all". I usually only do this, if I program a completely different example on the board or if I get a Mesh assert error right at the start.

You are using the access_model_publish_address_set-function to set the publication address. You can check if this succeeds by using the function ERROR_CHECK() on the status you get back.
But I suspect, that before setting the publication address  you first need to bind a appkey to the model. I think this is done by the provisioner.
I am using the nrf-mesh app on android and provision the nodes by hand. This means I do not bind the appkey as well as set the publication address in my program.

[ycp]

Hi Tierli,

i find i used printf() to print log , when i comment all the printf() functions , it works!! maybe it is the reason ,after comment them all,drop J-LINK can still run !!  i do not know why . i thank i should use __LOG instead , but i do not fully kown what it is..

[Biliban Tierli]

That makes sense. I think printf() sends the data to stdout and LOG will use the J-Link RTT.

[ycp]

yes!