adding custom characteristic to HRS

[Lakshmikanth Satyavolu]

Hi All,

I am trying to add custom characteristic to existing HRS profile. I am making few modifications to this profile for my custom requirement. 

I am adding new characteristic like below. 

 

// Add Last Packet Counter characteristic FIXME: remove hardcoding
memset(&add_char_params, 0, sizeof(add_char_params));

add_char_params.uuid = MY_CUSTOM_UUID;
add_char_params.max_len = 2;
add_char_params.init_len = 2;
add_char_params.p_init_value = 0;
add_char_params.is_var_len = true;
add_char_params.char_props.read = 1;
add_char_params.char_props.write = 1;
//add_char_params.cccd_write_access = p_hrs_init->hrm_cccd_wr_sec;
add_char_params.read_access = p_hrs_init->bsl_rd_sec;

err_code = characteristic_add(p_hrs->service_handle, &add_char_params, &(p_hrs->hrm_handles));
if (err_code != NRF_SUCCESS)
{
return err_code;
}

This code doesn't throw any error return code. Which means the characteristic is getting added successfully. 

But after adding this, I unable to see the data, and application hangs somewhere in the code always restarts and starting advertisement. 

Is there anything to be taken  care of apart from simply adding characteristic? Please guide me. 

However I am creating completely a new custom profile for my application. Meanwhile I would like to experiment with adding characteristics to existing profile and see how it works.

Please let me know what I am doing wrong. 

Regards

Lakshmi 

[Mttrinh]

Hi,

Try settting DEBUG in your preprocessor definitions/symbols and debug through your code and see if you see where the code hangs. Which function does the application stop at? Getting any error codes now?

[Lakshmikanth Satyavolu]

Hi Mttrinh,

Thanks for responding. I found the reason for hang. I am not declaring ble_gatts_char_handles_t handles for my custom characteristics. 

Now I able to connect with the nRF connect. But when I enalbe notifications, it is saying "sensor contact not supported" received. 

Why is it happening? 

Regards

Lakshmikanth 

[Mttrinh]

Hi, 

Are you using nRF Connect for Desktop or nRF Connect for iOS/Android?

[Lakshmikanth Satyavolu]

nRF connect ANdroid. 

[Mttrinh]

Hi,

There is a flag in the hrs packet that indicates whether or not, the Sensor Contact feature is supported. If it isn't detected then the sensor does't support this feature. I suggest you to have a look at the Heart Rate characteristic specification.