Continuous Wave or “CW” is a simple way to transmit Morse code over radio waves, and is still popular today, including in the form of contests, where enthusiasts race to generate codes as quickly as possible.

In addition to these encoding activities, decoding is also necessary if you want to understand what was transmitted, which is where PJRC forum member pd0lew’s CW decoder project comes in handy.

The project is based on a Teensy 3.6 + Audio Adaptor Board, with additional automatic gain control (AGC). Once the signal is decoded, it is output to an RA8875-based TFT LCD via SPI, which can accommodate five lines of text, and it can also be read over USB. A custom CNC-machined PCB ties it all together inside an attractive aluminum enclosure. Find out more on the CW monitor project page, or in the video below.

Before this final version housed in a beautiful enclosure, earlier versions were made without any case, and with a milled PCB and die cast enclosure.

In this video the older version can be seen and heard (starting at 0:47) displaying the Morse Code.