Description

SMS CW provides a Morse code interface for receiving and composing SMS messages on Pebble smartwatches. The application is intended for amateur radio operators and others familiar with conventional CW operation. 

CW timing is central to the application. Paddle input generates timed dits and dahs, while straight-key input allows the operator to control element duration directly. Character and word spacing are determined by keying intervals rather than separate spacing commands. 

Features 

CW Reception: Incoming messages can be converted to Morse code and played through the watch. 

Audio and Haptic Output: Configurable audible CW tones and vibration, with independent receive and send settings. 

Paddle Input: The upper and lower buttons operate as dit and dah inputs. Assignments can be reversed. 

Straight-Key Input: The center button provides manually timed keying, with element recognition based on press duration. 

Automatic Spacing: Character and word boundaries are determined by standard CW timing. 

Adjustable Parameters: Configure operating speed, tone frequency, volume, haptic synchronization, and straight-key decoding thresholds through the Pebble phone application's settings. 

Operation 

When a message is received, the operator can initiate CW playback on the watch. Playback follows the configured speed and audio or vibration preferences. 

Press and hold the lower button from Receive mode to enter Send mode. The upper and lower buttons provide paddle input, and the center button operates as a straight key. 

The application interprets pauses between elements to establish character and word boundaries. No dedicated space key is required. 

Development 

SMS CW was developed with assistance from generative AI through an iterative process commonly called vibe coding. The software has been compiled, tested, and revised through direct interaction with the hardware. 

The application may contain errors or limitations. Reports concerning CW timing, input decoding, audio synchronization, and device compatibility are welcome. 

Source Code and Android Companion 

The project is open source. 

https://github.com/Darachnid/pebble-cw-messenger 

The required Android companion APK and installation instructions will be provided through the repository when the release is available. 

Contributions 

Operators and developers are encouraged to inspect the source code, report defects, contribute improvements, or fork the project for further development. Contributions concerning CW timing, alternative keying methods, accessibility, and additional device support are particularly welcome.