Initial usb connection can take up to 30min

Hi All,

Im using the serial monitor sketch with an arduino uno usb connection.
I get a connection via dos
COM1 not found, or may be busy.
Select serial port [ COM2 COM4 ]: com4
Connecting device at com4 to
OpenC0C("\.\com4", baud=9600, data=8, parity=no, stop=1) - OK
Connect(“”, “8442”) - OK

But the actual time to connect to the cloud is 30 -40 min why?
After that I type marco and get polo, connection is good but the initial time to connect is hard to deal with.



Is there any help on this I am unable to connect and cant use blynk, as its too slow to connect, why would this be? I make a code change and the refresh can be 30 min to an hour…
I have tried:
different coms
port forwarding
disabling firewall
making sure dos is running as admin
different ports
resetting arduino

I am getting very slow connection.

Could anyone help please.

I think you’ve probably realised by now that the USB connection is only really there as a quick and dirty way of getting someone up and running with Blynk if all they have is a board with no form of internet connectivity.
It’s not a sustainable solution, as he computer being uses as the gateway needs to be on and the command window (the ‘dos’ as you call it) needs to be open all the time for the serial gateway to work.

Connection is normally very quick, provided you have the macro configured correctly.
The fact that you’ve messed-around with port-forwarding worries me. No port forwarding is necessary or appropriate unless you are running a local Blynk server that you wish to access from outside of your network, so any port forwarding changes you’ve made need to be undone.

You need to identify the COM port that your board is connected to. This is easier in Windows Device Manager, but you should be aware that plugging the board into a different USB port will probably result in a different COM port being allocated.

As far as the port is concerned, you seem to be trying to use an SSL port (8442). I’d suggest that you use port 80 or preferably 8080 instead.

Actually, the real solution is to buy a board that has built-in Wi-Fi connectivity such as a NodeMCU.


Thanks Pete for your information and time,
Its a shame, I wanted to use the usb as I was happy with the hardwired version of a gateway, oh well, I dont know why they use it on blynks YT videos if its a dirty way of using it as you say. Why would you promote this connection if it is suspect, it gave me a second guess experience on the whole thing. So moving forward, if wireless is the way I have a couple node mcus’ laying around as your write up states and ill give them a try. Ill take your advice and take off the port forward.
Once again thanks for your reply,


I think the reason for developing and promoting the USB connection method was because it’s a great way to get people started and interested. Lots of people have an Uno lying around, but no method of connecting it to the internet without getting an Ethernet shields or an ESP-01. This method allows them to try Blynk quickly and easily, and it’s great for that. Once people are hooked on the concept then it’s time to move-on to something like a NodeMCU to make full use of the functionality.
The same applies to Bluetooth to a certain degree - it appeals to people with no Wifi access, and gets them up and running with minimal additional hardware.

Ultimately though, if you want IoT then you need a sensible way of easily connecting to the internet, and WiFi is the simplest way of doing that for most people.


I see,

My reason for the hardwired gateway is I have been toying with lora radios and making mesh networks for long distance collection. I see you have many miles on this forum so may I ask a question. Is Ethernet more reliable for a hardwired master lora radio. Can you use the arduino mega say serial port to via blynk to speak through the serial port? Can you give me pointers on how to do that and where abouts in the reference to look. As I think the forum census states the software serial is what is used to print out but the Serial.print of the Arduino is used for communication with blynk so you dont touch it. Or, again do I stick with wifi and use it for the lora master.



Hi, I don’t have any personal experience of Lora, but there are a few people here who have.
I certainly wouldn’t use serial communications between devices.

Maybe if you explain more about what it is that you’re trying to achieve then we could give you some ideas.