Edit - Arduino Stack Exchange

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

Required fields*

Serial debug output looking messy

I've got this quite basic code running on an Arduino Mega 2560, and the output is looking like I have the serial settings wrong, though I can't work out what to change.

void setup() 
{
 Serial.begin(9600);
 Serial.println("test123");
}
void loop()
{
 Serial.println("test" + millis());
}

The output looks like this:

×ばつ¤¿ïßûÏûýoÏ¿îãõI
õfwi÷`p¬1⁄2Ïa»QáÀa»¦·ð¦·Z©÷
test123
D
4ñjü ̄÷~μÞMz1Ý~1⁄4
Ûþ}iû}ÒÖ¦Ç¿÷ÿÂï1⁄2Õ3⁄4;îö

I'm using the inbuilt "Serial Monitor" in the Arduino suite with settings 9600 baud and no line endings.

I see that the first println in setup() is sending the data as expected but all other comms are coming through as nonsense.

Any suggestions of what to do?

Answer*

Draft saved

Draft discarded

Edit Summary*

Cancel

Add a comment |

How to Edit

Correct minor typos or mistakes
Clarify meaning without changing it
Add related resources or links
Always respect the author’s intent
Don’t use edits to reply to the author

How to Format

create code fences with backticks ` or tildes ~
```
like so
```
add language identifier to highlight code
```python
def function(foo):
print(foo)
```
put returns between paragraphs
for linebreak add 2 spaces at end
_italic_ or **bold**
indent code by 4 spaces
backtick escapes `like _so_`
quote by placing > at start of line
to make links (use https whenever possible)

<https://example.com>

[example](https://example.com)

<a href="https://example.com">example</a>

formatting help »
answering help »

How to Tag

A tag is a keyword or label that categorizes your question with other, similar questions. Choose one or more (up to 5) tags that will help answerers to find and interpret your question.

complete the sentence: my question is about...
use tags that describe things or concepts that are essential, not incidental to your question
favor using existing popular tags
read the descriptions that appear below the tag

If your question is primarily about a topic for which you can't find a tag:

combine multiple words into single-words with hyphens (e.g. arduino-uno), up to a maximum of 35 characters
creating new tags is a privilege; if you can't yet create a tag you need, then post this question without it, then ask the community to create it for you

popular tags »