When you learn CW you’ll want to practice sending at some point. Many programs help you with that, but you’ll need to connect a paddle (or other key) to your computer somehow. Following you’ll find out how I did it.

Software

I used the package unixcw which provides a set of programs. For sending I use xcwcp, which is a GUI version of cwcp. The advantage of the GUI is that you can use the mouse as input. This option allows you to use the left and right mouse buttons for dits and dahs.

Hardware

Now you only need a way to connect your paddle to the computer, that the paddles are recognized as mouse buttons. For that I sacrificed an old, broken mouse. With a multimeter I found where the buttons and ground connected to the main board. Then I took a 3,5mm jack socket and soldered as following:

Tip   > Left Button
Ring  > Right Button
Sleve > Ground

Most paddles have a jack plug to connect which fits perfectly in the socket. Voilà, you can use your paddle with your computer.