characteristic with read & notify repeatedly update in nRF connect app with same value

RE: characteristic with read & notify repeatedly update in nRF connect app with same value

OldXiao — Tue, 04 Feb 2025 03:31:12 GMT

I have tested the orignal Blinky again, same. The nRF connect app will repeatedly update the LED state and button state.Looks like this is app's intentionally action.

So ignore it now, I will check with center app later.

By the way, about debug log, can I use the USB to output log to PC?

I have no JLink, only a 3rd vendor's CMSIS-DAP debugger.

I just tried JLink viewer with my debugger, it can't find the debugger.

And I don't want to connect another board between PCA10059 and PC.

Thanks.

RE: characteristic with read & notify repeatedly update in nRF connect app with same value

OldXiao — Tue, 04 Feb 2025 03:03:52 GMT

In my code as showed in attahed files,there only 1 place to call sd_ble_gatts_hvx():

uint32_t ble_tgoi_on_SOMI_change(uint16_t conn_handle, ble_tgoi_t * p_tgoi, uint8_t* data,uint16_t dataLen)
{
    
	  ble_gatts_hvx_params_t params;
    
    memset(&params, 0, sizeof(params));
    params.type   = BLE_GATT_HVX_NOTIFICATION;
    params.handle = p_tgoi->SOMI_char_handles.value_handle;
    params.p_data = data;
    params.p_len  = &dataLen;

    return sd_ble_gatts_hvx(conn_handle, &params);
    
		/*
	  ble_gatts_value_t p_value;
    p_value.len = dataLen;
    p_value.offset = 0;
    p_value.p_value = data;	
	  return sd_ble_gatts_value_set(conn_handle,p_tgoi->SOMI_char_handles.value_handle,&p_value); 
	  */
}

and this function called in button event handler:

uint8_t testCnt = 1;

static void button_event_handler(uint8_t pin_no, uint8_t button_action)
{
    ret_code_t err_code;
	  uint8_t data[10] = {0xFF,0xFF,0xFF,0xFF,5,6,0xFF,0xFF,0xFF,0xFF};

    switch (pin_no)
    {
        case LEDBUTTON_BUTTON:
            NRF_LOG_INFO("Send button state change.");
				
				    //测试，按下按钮时生成10个字节的数据，发送给server
				    
						data[4] = testCnt++;
				    data[5] = testCnt++;
				
            err_code = ble_tgoi_on_SOMI_change(m_conn_handle, &m_tgoi, data,sizeof(data));
            if (err_code != NRF_SUCCESS &&
                err_code != BLE_ERROR_INVALID_CONN_HANDLE &&
                err_code != NRF_ERROR_INVALID_STATE &&
                err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
            {
                APP_ERROR_CHECK(err_code);
            }
            break;

        default:
            APP_ERROR_HANDLER(pin_no);
            break;
    }
}

I have set break point in these functions,no stop during repeatedly sending last data.

That means those 2 functions not been executed.

Any other attributes can be set to control the data transfering between peripheral & center?

RE: characteristic with read & notify repeatedly update in nRF connect app with same value

Kenneth — Mon, 03 Feb 2025 15:47:03 GMT

I can't think of anything, unless you somewhere are calling sd_ble_gatts_hvx(). If you have a sniffer log that might help.

Kenneth

RE: characteristic with read & notify repeatedly update in nRF connect app with same value

OldXiao — Mon, 03 Feb 2025 14:42:22 GMT

Nice, it receives only 10 bytes now.

But,why It repeatedly send the last data?

It will not send any data if I never send data,and it will repeatedly send the last data if I send data once.

RE: characteristic with read & notify repeatedly update in nRF connect app with same value

Kenneth — Mon, 03 Feb 2025 12:48:56 GMT

Hello,

Before calling characteristic_add(), can you set:

add_char_params.is_var_len = true; /**< Indicates if the characteristic value has variable length.*/

Kenneth