The "cw" plugin for SDRuno is - as the name suggests - a plugin for decoding CW (continuous waves) signals.
Since cw is a small band signal (a few dozens of Hz in this plugin), the samplerate used as input for the plugin is 192000 samples/second. The SDRuno framework provides the 192000 samples/second stream using the SP1 port. Note that a small signal is hard to detect on a 2 MHz wide spectrum, so use the zooming facility of the main spectrum display to show a smaller signal.
The plugin itself can be stored in the folder for community plugins
The plugin is - as other plugins - developed under MSVC. Its functioning depends on lots of other "dll's" (Dynamic Load Libraries);
If a 0x000012f error is encountered on trying to load the plugin, it means that dll's from the Visual C++ Redistributable(VS 2015) are not found.
CW (continuous Wave) is probably the oldest communication form on radio. This plugin implements a - pretty straightforward - decoder.
The spectrumdisplay shows a width of 62.5 KHz, CW signals are easily recognizable. Tuning to a CW signal is howver not always easy: the transmissions in the amateur bands are usually short. Happily, the main spectrum display on SDRuno has an excellent zoom facility, furthermore, there is an auxiliary (small) spectrum window, on which further zooming in is possible.
A key issue in decoding is the WPM (words per minute): they decide what the length of a dot, a space and a dash are. The default setting in the plugin is 30 WPM, the catch range is then roughly 20 .. 40.
The current implementation has an additional button that - when enabled - is able to shift the signal frequency a few Hz towards the nearest strong signal.
The implementation of the algorithm is taken from the swradio-8 implementation.