Adding Characteristic User Description 0x2901,0x2902

RE: Adding Characteristic User Description 0x2901,0x2902

Stian Røed Hafskjold — Mon, 27 Apr 2015 08:16:50 GMT

I gave you the answer to this on friday, in the Mypage support portal. A quick search in the forum returns this: devzone.nordicsemi.com/.../

That is the 0x2901.

Add these lines to your code:

static char user_desc[] = "name";
char_md.p_char_user_desc  = (uint8_t *) user_desc;
char_md.char_user_desc_size = strlen(user_desc);
char_md.char_user_desc_max_size = strlen(user_desc);

RE: Adding Characteristic User Description 0x2901,0x2902

Ulrich Myhre — Mon, 27 Apr 2015 08:00:00 GMT

What does the call-stack look like when you end up in the app error handler? What error code are you seeing? If the UD writable you must set the wr_aux flag to 1. I believe this is your problem now.

RE: Adding Characteristic User Description 0x2901,0x2902

Milan — Mon, 27 Apr 2015 06:45:43 GMT

doing same for char_md.p_user_desc_md stops advertising. LED1 doesn't blink after assigning char_md.p_user_desc_md = &ud_md; //ud_md is different instance

RE: Adding Characteristic User Description 0x2901,0x2902

Ulrich Myhre — Fri, 24 Apr 2015 13:33:00 GMT

Again, 0x2901 is User Description. To add the User Description, the char_md.p_user_desc_md must be set as well. Do the same as you do for CCCD, but use different ble_gatts_attr_md_t instances of course.

RE: Adding Characteristic User Description 0x2901,0x2902

Milan — Fri, 24 Apr 2015 13:22:57 GMT

//mj uint32_t err_code; ble_gatts_attr_md_t cccd_md; ble_uuid128_t nus_base_uuid_char = NUS_BASE_UUID_CHAR;

memset(&cccd_md, 0, sizeof(cccd_md));

BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);

cccd_md.vloc = BLE_GATTS_VLOC_STACK;
//mj

memset(&char_md, 0, sizeof(char_md));
	char_md.char_props.indicate			 = 1; //mj
char_md.char_props.write         = 1;
//char_md.char_props.write_wo_resp = 1; //mj
char_md.p_char_user_desc         = NULL;
char_md.p_char_pf                = NULL;
char_md.p_user_desc_md           = NULL;
char_md.p_cccd_md                = &cccd_md; //mj NULL earlier
char_md.p_sccd_md                = NULL;

Still not showing 0x2901 in Mobile Application.

RE: Adding Characteristic User Description 0x2901,0x2902

Ulrich Myhre — Fri, 24 Apr 2015 11:22:30 GMT

Please read the document I linked. 0x2901 is Characteristic User Description. 0x2902 is Client Characteristic Configuration.

RE: Adding Characteristic User Description 0x2901,0x2902

Milan — Fri, 24 Apr 2015 11:20:45 GMT

Hi! I need to add 0x2901 and not 0x2902. was it typo?

RE: Adding Characteristic User Description 0x2901,0x2902

Ulrich Myhre — Fri, 24 Apr 2015 11:09:22 GMT

First of all, here is a reference explaining what the adopted UUIDs mean: developer.bluetooth.org/.../DescriptorsHomePage.aspx. You are lacking a User Description and a CCCD for your characteristic.

To add a user description, see here: developer.nordicsemi.com/.../a00283.html. The p_user_desc_md must be pointing to a proper ble_gatts_attr_md_t. This is very close to how you add a CCCD, so you can look in other examples how that is done. Also set char_ext_props.wr_aux to 1 if it is writable.

Simply add a CCCD to add the UUID 0x2902 descriptor.

RE: Adding Characteristic User Description 0x2901,0x2902

Milan — Fri, 24 Apr 2015 10:56:36 GMT

I don't have any information regarding peer device is doing proper discovery or not.
Only available information is Mobile app and Blugiga device using some propriety service called cable replacement and I am trying to achieve same in nordic soc by modifying ble_uart app.

I don't have idea how to add 0x2901 descriptor. Using Nordic's Master Control android app shows 0x2902 descriptor and I need to add 0x2901.

RE: Adding Characteristic User Description 0x2901,0x2902

Ulrich Myhre — Fri, 24 Apr 2015 10:39:00 GMT

Are you depending on hard-coded handles or will the peer device do a proper discovery? Handles are given out sequentially, so it is not possible to guarantee that every declaration will be given the same handle as the device you are copying.

Please also list how you are unable to add user description fields. How are you trying to do it, and what return codes do you see?