Writable values on services

RE: Writable values on services

Edvin — Mon, 21 Sep 2020 13:36:15 GMT

Then I suggest you look into the ble_app_uart example.

You can read the test description here.

BR,
Edvin

RE: Writable values on services

Zero.cool — Mon, 21 Sep 2020 11:51:46 GMT

You're right.
Actually I will try to explain here,
In project we have IOS app, which is hiding mac of device + generic attributes, and only exposing services.
So I just wanted to check If I can make one service with writable such that data sending from IOS can be tried.

your suggestions are most welcome here :-)

RE: Writable values on services

Edvin — Mon, 21 Sep 2020 10:59:20 GMT

You can try to make the battery service writable, just for testing.

It would be adding something like:

add_char_params.char_props.write = 1;

after

add_char_params.char_props.read = 1;

And then you would have to implement something to handle the write events in the on_write() function in ble_bas.c.

However, the heart rate characteristic is only one byte by default, so you would have to change that if you want to send more data:

    add_char_params.max_len           = sizeof(uint8_t);
    add_char_params.init_len          = sizeof(uint8_t);

To be honest, it may be easier for you to add the nus service from the ble_app_uart example. Look at how it is implemented in that example. Using that service, you are free to send more data, and you can send this custom data both ways.

RE: Writable values on services

Zero.cool — Mon, 21 Sep 2020 10:07:55 GMT

Ok,

So, Is there any service I can make it as Writable in heart rate example just to quickly check for one experiment.
or I need to create one service to make it writable. ?

RE: Writable values on services

Edvin — Mon, 21 Sep 2020 08:55:37 GMT

Hello,

According to the Battery Service specification, which you can find here (click on the 1.0-link next to "Battery Service"), the battery level characteristic can not be written to:

So while it probably is possible to implement it, you will not be able to certify the product with Bluetooth if that is possible.

Best regards,

Edvin