Traffic Light
Calibration Status
Please perform one of the following calibration tests ...
Short test: Click the 'Reset' button, then key in the letter 'V' three times, dot-dot-dot-dash dot-dot-dot-dash dot-dot-dot-dash. When finished, press the 'Short Test' button.
Long test: Click the 'Reset' button, then key in the word 'PARIS' three times. Finally, press the 'Long Test' button.

After completing one of the calibration tests described above, key in a 'made up' test message. If the keyed message does not display automatically or contains unexpected errors, click the 'Show text' button. (Do not click reset.)

To listen to your keyed-in text sample as Morse code (Chrome or Edge only), correct any errors in the 'Show Text' panel above and then click the 'Play' button.


Acknowledgements and References

Morse code key image adapted from
Traffic signal images adapted from

The full version of this web page makes use of EWD.js together with GT.M, an enterprise database engine, to demonstrate two-way communication via Morse code between different computers on the same Local Area Network. Previously, on another page I summarized my effort to learn EWD.js. There I included one or two EWD.js applications for download as zip archives. One of these is a light IDE, which I have continued to use in subsequent studies, including the present page. Components of the EWD.js Morse code application (this page) may be extracted from The zip archive includes a text file named ‘How_to_install.txt’ and another file named ‘my_cw.pdf’ that explains how to use the EWD.js-connected version of this page. Of course, a functional EWD.js environment is required to install and use this version.

Disclaimer: The contents of this page are intended solely for entertainment. The author makes no claim as to the interest or value of information presented. Any educational benefit is purely accidental. In no event will the author be liable for any damages or lost effort, or anything else related to a decision to install or use this application.