I've just started on a project recently called Const Port. (Name is subject to change) The project has now been approved as a Handmade Network project. You can find it here: https://constport.handmade.network/
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Description:
Const Port is a custom designed application for reading and writing to serial COM ports. The current design is focused around providing a smooth and appealing way for firmware engineers to read serial output from embedded applications. The application is aimed at being simpler and more directed than alternatives like Putty and Tera Term while also being cleaner and easier to use. Everything is rendered in OpenGL giving a consistent feel across platforms as well as providing the ability to fully polish the interaction and design of the menus.
Currently Const Port is very early in development. The project should be runnable on any Windows 7+ (x64) based system but has only been tested on Windows 10. The platform layer is mostly in place but will heavily modified for robustness. The application itself supports only the minimum functionality at the moment. Much of the interaction is still done through keyboard shortcuts. Much of the configuration GUI has not been completed yet, which means it will not be suitable for most people as of now. You can, however, download a release of the application if you would like to test and experiment with it. Or you can download the source code if you'd like to compile it yourself.
You can download the initial release from http://www.siltutorials.com/blog/2017/6/18/const-port-v10
Or you can download the Source Code from BitBucket: https://bitbucket.org/stampede247/constport
Const Port is being developed by single person and largely for personal use. I do not guarantee it will work on all platforms. However, I would like to get it to a point of stability that it might be released as a fully Open Source and cross platform project that people can contribute to. If you are interested in helping with the project in it's early stages, send me an email at [email protected]. For further information about me and my projects you can visit my website: https://www.siltutorials.com/
Screenshot:

Versions:
1.0
- View a list of available COM ports (obtained via attempts to connect to known COM port names)
- Connect to a COM port at static settings (115200 baud, 8bits, No Parity, 1 Stop Bit)
- Entire GUI is rendered in custom OpenGL code (GLFW and GLEW used for window and context creation)
- Support for a large number of lines before we start to drop below 60 FPS
- Text is rendered to Bitmap Font using STB TrueType (Temporary implementation version)
- Text selection using custom outline shader
- Timestamps saved for each line of text received (Recorded at receive of first character in the line)
- Hover over a line and hold cntrl for "Time Ago" readout (Hold Shift for formatted date-time)
- Copy selected text to clipboard (Ctrl+C)
- Currently only supports ANSI characters but handles invalid ANSI characters gracefully
- Type into the view port to send ANSI characters (No auto-echo at the moment)
- Enter sends line feed character '\n'
- Line numbers displayed on left (with hovering position in the status bar)
- Ctrl+Shift+C to clear screen
- Ctrl+A to select/deselect all
- Ctrl+O to open COM port window which shows available COM ports. Click on one to connect to it
- Carrot rendered at mouse hover position, along with hovering line is slightly different color
- Home and End go to beginning and end of buffer
- PageUp and PageDown to move a page of text (or click above or below scrollbar)
- Auto follow end of buffer ONLY if you are scrolled to the bottom already
- Should support 64 bit Windows 7-10 operating systems (Though currently testing has only been done on Windows 10)
- Scroll wheel and arrow up/down to move view
- Platform layer loads the application code from a DLL allowing run-time reloading of the application code
- Platform layer is coded in a very "Handmade Hero Way" with minimal function calls in-between the two layers
- Color of line can be determined by application by sending 0x01-0x04 invalid ANSI characters at the beginning of the line (These are not rendered on the screen and do not get copied to clipboard when selected)
- Application icon is embedded in executable (Currently not loaded into the window information though)