Blynk 앱을 이용하여 arduino uno로 LED 켜보기 하려는데, 아래 부분에서 에러가 뜨며 연결이 안되네요.

답변 부탁드립니다.

C:\Program Files (x86)\Arduino\libraries\blynk-library-0.2.1\scripts>blynk-ser.bat -c COM3 -b 9600 -s cloud.blynk.cc -p 8442
COM3 not found, or may be busy.
Select serial port [ ~1 ]:
Connecting device at COM3 to cloud.blynk.cc:8442...
OpenC0C("\\.\COM3", baud=9600, data=8, parity=no, stop=1) - OK
Connect(): connect("cloud.blynk.cc", "8442") ERROR Unknown error (10061)
Reconnecting in 3s...

0초 기다리는 중, 계속하려면 아무 키가 누르십시오 ...
OpenC0C("\\.\COM3", baud=9600, data=8, parity=no, stop=1) - OK
Connect(): connect("cloud.blynk.cc", "8442") ERROR Unknown error (10061)
Reconnecting in 3s...