event form read request

[Shimon_nohayo]

Hi,

I'm using SDK 15.2 with Nrf52832,

I've implemented a custom service with read, write and notification services.

I would appreciate if you could send me an example of how to get an event of a read request, I understand that its part of the SodtDevice and I can get authorize read event - but it is not clear how...

Shimon

[Vidar Berg]

Hi Shimon, 

Normal read requests are handled without application interaction. If you want to receive an event you need to enable authorization like you indicated (MSC). Below is a diff showing the changes needed to enable this in the ble_app_blinky_example.

Fullscreen auth_read.diff Download

diff --git a/components/ble/ble_services/ble_lbs/ble_lbs.c b/components/ble/ble_services/ble_lbs/ble_lbs.c
index 1c83a99..5324428 100644
--- a/components/ble/ble_services/ble_lbs/ble_lbs.c
+++ b/components/ble/ble_services/ble_lbs/ble_lbs.c
@@ -60,6 +60,24 @@ static void on_write(ble_lbs_t * p_lbs, ble_evt_t const * p_ble_evt)
     }
 }
 
+static void on_rw_authorize_request(ble_lbs_t * p_lbs, ble_evt_t const * p_ble_evt)
+{
+      ble_gatts_rw_authorize_reply_params_t        reply_params;
+      ble_gatts_evt_rw_authorize_request_t const * p_evt_rw_auth = &p_ble_evt->evt.gatts_evt.params.authorize_request;
+
+      memset (&reply_params, 0, sizeof(ble_gatts_rw_authorize_reply_params_t));
+
+      if ( (p_evt_rw_auth->type == BLE_GATTS_AUTHORIZE_TYPE_READ) &&
+           (p_lbs->button_char_handles.value_handle == p_evt_rw_auth->request.read.handle))
+      {
+          reply_params.type = BLE_GATTS_AUTHORIZE_TYPE_READ;
+          reply_params.params.read.gatt_status = BLE_GATT_STATUS_SUCCESS;
+
+          (void) sd_ble_gatts_rw_authorize_reply(p_ble_evt->evt.common_evt.conn_handle, &reply_params);
+          
+      }
+
+}
 
 void ble_lbs_on_ble_evt(ble_evt_t const * p_ble_evt, void * p_context)
 {
@@ -71,6 +89,10 @@ void ble_lbs_on_ble_evt(ble_evt_t const * p_ble_evt, void * p_context)
             on_write(p_lbs, p_ble_evt);
             break;
 
+        case BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST:
+            on_rw_authorize_request(p_lbs, p_ble_evt);
+            break;
+
         default:
             // No implementation needed.
             break;
@@ -106,6 +128,8 @@ uint32_t ble_lbs_init(ble_lbs_t * p_lbs, const ble_lbs_init_t * p_lbs_init)
     add_char_params.max_len           = sizeof(uint8_t);
     add_char_params.char_props.read   = 1;
     add_char_params.char_props.notify = 1;
+    add_char_params.is_defered_read   = 1;
+
 
     add_char_params.read_access       = SEC_OPEN;
     add_char_params.cccd_write_access = SEC_OPEN;

If anything is unclear, let me know. 

Vidar

[ref]

Hi Shimon,

I have a similar problem of getting an event for a read request. Searching for answer I ran into this post. I followed your recommendation above and modified my code based on the example you provided. Unfortunately, I didn't work out for me. As soon as I add this line:   add_char_params.is_defered_read   = 1;  the NRF_connect freezes for a few seconds and then gives me "Gatt timeout error". If I remove this line, everything works well, except I won't get any event for my read requests.  I was wondering if you have any comments.

I really appreciate any help.

Thanks,

Reza

[Shimon_nohayo]

Hi Reza,

Sorry for the late response 

In the service init did you add:

// Initialize CUS Service init structure to zero.
cus_init.evt_handler = on_cus_evt;

BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.cccd_write_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.read_perm);
BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cus_init.custom_value_char_attr_md.write_perm);

err_code = ble_cus_init(&m_cus, &cus_init);
APP_ERROR_CHECK(err_code);
}

?

[ref]

Hi Shimon,

Thanks for you reply. I used the following to set the security open:

add_char_params.char_props.read = 1;
add_char_params.char_props.notify = 1;
add_char_params.is_defered_read = 1;

add_char_params.cccd_write_access = SEC_OPEN;
add_char_params.read_access = SEC_OPEN;

Basically, I followed Vidar's example code (above). The example seems very simple but I get the error below:

Error when calling 'reduceApp': Cannot read property 'toUppedCase' of null

I appreciate any comment.

Thanks,

Reza

[ref]

Hi Shimon,

Sorry for multiple posts. I just found what the problem was. I make a mistake when I copied Vidar's example. I copied the whole example and it worked. 

Thanks again for your help.

Sincerely,

Reza

[Shimon_nohayo]

Great, happy I could assist.