Discovery DIS

RE: Discovery DIS

anSolo — Wed, 14 Jul 2021 08:11:53 GMT

I've created message on zephyr mailing list

I write here, If any updates

Thank you for the help!

Please, keep me updated If nordic developers find a solution.

RE: Discovery DIS

Simon — Tue, 13 Jul 2021 12:55:20 GMT

It seems like most of the developers are on vacation. Can you forward the question to any of these places: Zephyr - Asking for help.

If you find a solution, would you be able to share it here, so other people can benefit?

However, I think a workaound is to run bt_gatt_read() two times, with dis->read_params.handle_count = 1;

RE: Discovery DIS

Simon — Mon, 12 Jul 2021 14:13:26 GMT

I'm able to reproduce it. I'm not sure how to go about this, so I have forwarded the question internally. I will keep you updated.

Best regards,

Simon

RE: Discovery DIS

anSolo — Fri, 09 Jul 2021 09:44:12 GMT

I do the same as in the example you provide,

Maybe I didn't describe it correctly,

the problem is that in multiply read I get one callback and one length for all values,
and I don't understand how to split it, and what value for what characteristic is.

RE: Discovery DIS

Simon — Thu, 08 Jul 2021 09:23:12 GMT

I took a brief look at it yesterday, but I would need some more time to understand this.

One option is to run bt_gatt_read with a single handle two times.

You could also take a look at zephyr/subsys/bluetooth/shell/gatt.c

RE: Discovery DIS

anSolo — Wed, 07 Jul 2021 06:02:17 GMT

devzone.nordicsemi.com/.../central_5F00_and_5F00_peripheral.rar

Here you can see my code

RE: Discovery DIS

Simon — Tue, 06 Jul 2021 09:55:03 GMT

Could you upload the code for central_hr and peripheral_hr in zipped format, so I can better understand what you're trying to do?

RE: Discovery DIS

anSolo — Mon, 05 Jul 2021 07:31:54 GMT

Thank you,

I tried it and it works!

I have question about bt_gatt_read().

dis->read_params.func = gatt_read_cb;
dis->read_params.handle_count  = 2;
dis->read_params.handles = dis_handles;
err = bt_gatt_read(dis->conn, &(dis->read_params));

I read two values,

BT_UUID_DIS_MODEL_NUMBER, which is "Model"

and BT_UUID_DIS_SERIAL_NUMBER, with value "serial"

Here you can see part of my log,

gatt read cb

data length 11

data = Modelserial

gatt read cb

data length 0

empty data

1)Is it OK that I get common length for two values, and values are not separated?

How could I split them?

2)Is it OK that I get extra callback with zero length?

RE: Discovery DIS

Hung Bui — Fri, 02 Jul 2021 15:01:20 GMT

Hi anSolo,
I haven't tried on my own to discover and read DIS characteristic, but you can refer to the bt_bas_handles_assign to do something similar.

So you need to make a similar function and instead of assign the BAS service , you call
if (bt_uuid_cmp(gatt_service->uuid, BT_UUID_DIS)) {

After that you need to look for the characteristics inside the DIS service, for BAS it's handled in bt_bas_handles_assign()

So instead of bt_gatt_dm_char_by_uuid(dm, BT_UUID_BAS_BATTERY_LEVEL); you can call bt_gatt_dm_char_by_uuid(dm, BT_UUID_DIS_MODEL_NUMBER); After that you need to get the characteristic handle using bt_gatt_dm_desc_by_uuid()

After you get the characteristic handle, you can do a read of the characteristic using bt_gatt_read(). Note that the DIS service doesn't support notification, so unlike the BAS service, you don't enable notification, you do a read instead.