Advertise two services at the same time?

[devops]

EDIT: I have added the battery data in percentage to scan response manufacturer specific data. Is that the only possible way?

Hello,

I am working on a beacon application that updates the advertisement every second.

I have a "time counter", so to say, that is stored in the manufacturer specific data. Additionally, I have a "temperature" or "rotation speed" service. It depends on the hardware of the node.

I would like to advertise a second service for seeing the battery percentage status but cannot figure out how to do it. I tried to do this but obviously it seems I just overwrite first temperature advdata with battery data and then I advertise only battery service. I would like to see both temperature and battery data on the nRF Connect app.

uint8_t rotation_data[] = {value_0,value_1,value_2,value_3};
rotation.data.p_data = rotation_data;
rotation.data.size = sizeof(rotation_data);
rotation.service_uuid = 0x1815; //Official SIG temperature service
init.advdata.p_service_data_array = &rotation;
    
uint8_t battery_data[] = {percentage_batt_lvl};
battery.data.p_data = battery_data;
battery.data.size = sizeof(battery_data);
battery.service_uuid = 0x180F; //official SIG battery service
init.advdata.p_service_data_array = &battery;

[Simon]

What you are doing now is to just overwrite the old data (as you mentioned). What you need to do is the following:

#define SIG_TEMP_SERVICE_UUID 0x1815 //Official SIG temperature service
#define SIG_BAT_SERVICE_UUID 0x180F  //official SIG battery service

ble_advdata_service_data_t service_data[2] = {};

//Creating data structure for temperature
uint8_t rotation_data[] = {1, 2, 3, 4, 5};
uint8_array_t rotation;
rotation.size = sizeof(rotation_data);
rotation.p_data = rotation_data;

// Adding temperature "service" to service_data array
service_data[0].service_uuid = SIG_TEMP_SERVICE_UUID; 
service_data[0].data = rotation;


//Creating data structure for battery
uint8_t battery_data[] = {6, 7, 8, 9, 10};
uint8_array_t battery;
battery.size = sizeof(battery_data);
battery.p_data = battery_data;

// Adding temperature "service" to service_data array
service_data[1].service_uuid = SIG_BAT_SERVICE_UUID; 
service_data[1].data = battery;

init.advdata.service_data_count = 2;
init.advdata.p_service_data_array = service_data;

The changes I made from your code was roughly:

• Created an array of type ble_advdata_service_data_t and assigned the temperature info to field 0 and the battery info to field 1
•  Set the field init.advdata.service_count to 2
• Excluded the & sign when assigning service_data to the init structure, since the variable is turned in to pointer when declared as array

The reason for these changes can be found in the function advertising_init()->ble_advdata_encode(..)->service_data_encode(..)

service_data_encode(..){
.
.
for (i = 0; i < p_advdata->service_data_count; i++)
{
    ble_advdata_service_data_t * p_service_data;
    uint32_t                     data_size;

    p_service_data = &p_advdata->p_service_data_array[i];
.
.

As you can see, it will only encode as may GAP data types of "Service Data" as specified by service_data_count. 

Best regards, Simon

[devops]

Thank you for such a thorough response. I will try to implement the changes you described over the weekend and will update the post.

EDIT:

Your solution works very well and I have implemented it to my code. I removed the scan response packet and am now advertising two services instead. The current consumption should go down as well, right?