Serial Monitor Extended

Serial Monitor Extended (beta)

I proudly present the "Serial Monitor Extended" application to you. When I started working with Arduino, I wasn't satisfied with the overall options of the official Serial Monitor, so I decided to write my own.

The interface is quite similar to Arduino IDE's own Serial Monitor, but with some tweaks.
This is a work in progress, so expect to see improvements and new features in the future.

Download Now! - Links: Serial Monitor Extended | David Refoua's blog
Please do NOT mirror at all!


    • Auto Close: Using the 'Keep Open' option you can decide whether to keep the port open, or open it ONLy when sending data.
    • Better Status: Now you can actually see if you are connected to a specified port or not, visible at the top of the form.
    • Easy Port Switch: Now you can also easily change the port, without closing the window to change it from the toolbar. You don't even need to close the port to change it!

(Note: To change the port, click on the 'Port COMx is OPEN/CLOSED.')

    • Name Friendly: You can now see what port you are actually connecting to, rather seeing a number. (This is useful for non-Arduino chips and clones, Arduino already shows you what Arduino device are you connected to.)
    • Error Messages: This app will show you a clear and easy-to-understand error message, if anything goes wrong.
    • Line Ending: The line ending selection is now easier, and prettier.

Known Issues:
This is a beta version and may have some problems. One known issue is that the app may freeze if you select a wrong baud rate for now. Don't worry, I will fix it soon.

I will implement these features in the future:

  1. Serial to Mouse, Keyboard, Midi controller bridge.
    (Cool, isn't it? :smiley: I'm working on it)
  2. Disable Auto-Reset by software.
    I know that many people are sometimes annoyed by the arduino's auto-reset on opening a new connections. While there are hardware solutions available,
    I have written a small function to disable the DTR pin while transmitting data. I'll merge that code into Serial Monitor Extended soon.
  3. Serial to TCP connection
    This can be a replacement to setups like Node.JS, a stand-alone easier app. The difference is that you can use the monitor and the network at the same time!
  4. Support for Hyper Terminal's Cursor control escape characters.
  5. Terminal Color Support (+Easy Arduino Library)
  6. Log for sent data, also a history list to automatically re-enter the previous sent data

Misc. Notes:
I hope you like this software. 'Serial Monitor Extended' is a free, and open-source app written by me ( The source-code is written in C# and will be soon available in GitHub, for enthusiastic people.

Please use and share your opinion!
Post your feedback here: Arduino IDE Serial Monitor Improvements [+READ] - Interfacing w/ Software on the Computer - Arduino Forum


I also were not satisfied with the standard Serial Monitor and made my own alternative. I'm wondering if and how you solved a problem I had:

Ideally I would want to make the Arduino IDE start the alternative serial monitor instead of the normal monitor or perhaps via a new menu item. Did you manage to implement this and so how did you do this?

cheers, Nard

Hey @Nard,

Your alternative app seems so promising! As for the question you asked, I actually had the same problem and after hours of Googling, I finally gave up looking for an official solution. Apparently, the Arduino IDE developers that it would be cool to have an external text-editor, but not an external Serial Monitor.

Unofficially, Since I also program in Java, I downloaded the source code for the IDE from GitHub, changed the button to launch my .EXE file, and compiled. It's a simple solution, but I have to modify the code and compile it every time there's an update. I considered pulling a request, but I fear it will get rejected. Most of the times, developers wouldn't like an ideas if it's useful only to a select few. (Even if you already have written a full source-code.)

Now bear with me, I think Arduino lacks both a proper text editor and a proper serial monitor. I really liked your ideas and the app you wrote using Processing, and would like to implement something similar in my own app.

I am also a web designer, and have worked with other Arduino and non-Arduino serial-based monitoring and control software, both written natively and in Web. Would you like to work on a powerful, complete, simple and easy use Serial monitor for general purposes?

I think it can be a great app, and with proper advertisement to Arduino users plus begging asking the official developers, we could be able to finally integrate it into Arduino IDE.

PM me if you are interested!

I like the work both of you have started.

I am interested in extending the serial monitor to it reacts to the cursor/display commands that work with New Haven LCD displays.

Is either of you still actively working on this?

Does anyone have interest in Terminal commands?

I read A better terminal program (Serial Monitor)? - Project Guidance - Arduino Forum and I under @barryjo's frustration with the serial monitor.