Arduino IDE Blank Serial Monitor

I’m new to Arduino and have a Seeeduino Wio Lite W600 I’m learning on.

I’m currently just trying to get something to show up on the Serial Monitor in Arduina IDE with simple “Hello World” code:

void setup() {

void loop() {
Serial.println(“Hello, world!”);

I can Compile and Upload successfully, but Serial Monitor is blank.

Any ideas what I can try to get the data to the Serial Monitor?


I’ve been doing some more digging and I’m wondering if this could be due to a USB Driver issue? Does anyone have any information of where I can find a USB Drive for the Wio Lite W600? I can’t find one in the Wiki or anywhere else online.

Which is the Arduino board JSON link you are using?

If you really can upload successfully then the USB drivers should be fine I would think.

Since you set your baud rate in the code to 9600… so did you have the Serial Monitor set to the same baud rate? If not it will often print garbage or not print anything at all.


I detected the same problem as @jrosshort.
This is the simple testing code I used at first, with a relay:

void setup() {
pinMode(5, OUTPUT); // initialize pin D5 as OUTPUT

void loop() {
digitalWrite(5, HIGH); // turn relay on
Serial.println(“Relay on”);
digitalWrite(5, LOW); // turn relay off
Serial.println(“Relay off”);

Relay switches on and off fine…but the serial monitor remains empty.
I tried the “hello world” code too. No difference.
Baud rates are matching.
JSON link:

Hey Baozhu,
Thanks for following up on this!
I am using as the Arduino board JSON. Let me know if there is a different link I should be trying?

Hey Dennis,
That’s what I thought as well, so I’m confused. I confirmed the baud rates are matching with a few different sets of code I tried… Any other thoughts on what i could try?

Since I do not have this board I had to do a little digging and found that Serial seems to be the UART pins, not for printing over the USB.

To print over the USB serial port replace “Serial” with “SerialUSB”.

This is similar to how the Arduino DUE and ZERO work as well which are also SAMD21 processors. Let me know if this works.


void setup() {

void loop() {
   SerialUSB.println(“Hello, world!”);
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From our Wiki documentation,
You should use the link below.

Brilliant!!! Thanks so much Dennis, that worked!
Appreciate it.

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Hi @Baozhu,

I do not find Wio Lite W600 among the boards in the Arduino IDE.

Using the other json I cyted earlier I did for a while, but for 2 days I haven’t find either.
What mistake I do?
Recently we have adjusted the software, please use the product according to the Wiki @vidist

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Well, setting w600 as Wio Lite MG126 works as a temporary solution…thanks.

@vidist, I’ve also been able to get it to work using Arduino MKRZERO.

Hi @jrosshort, yes that works and MKR Wifi 1010 too. The main challenge here is to use the wifi…

Hey @vidist,
Based on this thread (Seeeduino_samd_zero is not listed in Arduino IDE board manager), the board configuration file should now be fixed and you should select Seeeduino Zero as the board (Wio Lite 600 is included there).
Hope that helps.