Nus profile seems to cause system reset if the data length too long.

[Ted]

iphone5_b.psdm370_android6_b.psdlong_write_error.pngI using SDK11. I porting nus profile to my system and make a customer's UUID. I use Lightblue on iPhone 5 to connect my system. I sent a data through my customer's UUID. My system work fine when the data length is less than or equal 20 bytes. It will cause system reset if the data length is great than 20 bytes. Was the softdevice error, or I made something wrong?

[Petter Myhre]

The system is probably reset because APP_ERROR_CHECK() is called with something else than NRF_SUCCESS (0x00000000) somewhere. If you call ble_nus_string_send() with a longer length than 20 bytes it will return NRF_ERROR_INVALID_PARAM.

The maximum ATT MTU with the S130 v2 is 23 bytes, the header is 3 bytes, so up to 20 bytes of data is allowed.

[Ted]

Oh, it is very strange. I use your code and then I send 22-byte data. I receive BLE_EVT_USER_MEM_REQUEST event 1 time and call the API of sd_ble_user_mem_reply(m_conn_handle, NULL). Then I get first BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST event and call the API of sd_ble_gatts_rw_authorize_reply(m_conn_handle, &rw_authorize_reply_params). I get the error code == 0. (success). Then I get second BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST event and call the API of sd_ble_gatts_rw_authorize_reply(m_conn_handle, &rw_authorize_reply_params). I get the error code == 7. (failure. system reset).