This is an Arduino Nano-based Morse key/paddle <-> USB Serial interface and simple keyer, for use in the DigiMorse project.
It has been built using the Arduino IDE v1.6.4 on Windows 10, and uploaded to a third-party Arduino Nano, using the CH340 USB Serial chip. Also buildable in the v1.8.16 IDE on macOS 10.15 (Catalina) (use the 'ATmega328P Old Bootloader' version).
https://www.amazon.co.uk/gp/product/B072BMYZ18/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.elegoo.com/products/elegoo-nano-v3-0
I'd normally use a genuine Arduino, which I'd recommend, but had this to hand. It's £10.99 for a pack of 3 in Nov 2020. The genuine one is £21.60 (for one).
Use of this variant requires downloading their CH340 USB driver.
It is part of the DigiMorse Project.
(C) 2020-2021 Matt J. Gumbley matt.gumbley@devzendo.org @mattgumbley @devzendo http://devzendo.github.io/digimorse
Project started September 2020. Status: initial investigations, feasiblilty, thoughts.
In active development:
- Building the keyer.
First release:
- Sends on/off keying data to the host computer.
- Can sense switches of key or paddle.
- Straight key signalling only (no keyer).
Second release:
- Accepts commands, implements keyer.
- Sidetone generated on-board? (Would be better if this could be generated in real time via the host computer.)
0.0.1 First Release (work in progress)
- Created repository!
The keyer uses the Arduino's Serial over USB protocol, so can be checked with the Arduino IDE's serial console.
When the board initialises, it sends version information to the host in the form of a comment. All comments are to be ignored by the host (they could be logged if necessary). Comments start with a # and end with a \n.
Tapping the Morse key or paddle causes timing events to be emitted. The initial down-press of the key will emit a 'start of keying' code, an ASCII S.
As you release, at the end of the key down, a 'press' code will be emitted. This is a '+' followed by a 16-bit big-endian unsigned binary number giving the duration of the press in milliseconds.
When you next press the key, a 'release' code will be emitted. This is a '-' followed by the duration of the release in milliseconds, as for '+'.
The keyer has a timeout of one second. Currently not configurable. One second after the last event, an 'end of keying' event will be emitted. This is an ASCII 'E'.
In addition to events from the keyer, commands can be issued to change several settings, and to enquire of device status, version, etc.
All commands must start with a '>' (greater than) then the command letter, with any value following immediately, then a return.
>V<return> Display version info.
>!RESET!<return> Reset to all defaults.
(more commands to be implemented in time....)
'S' Start of keying. '+' HH MM Press for HHMM milliseconds. '-' HH MM Release for HHMM milliseconds. 'E' End of keying.
Full documentation to follow.. but in the meantime...
Load digimorse-arduino-keyer.ino into the Arduino IDE. Connect your Arduino Nano via USB. Choose the model and port. Upload...
In the IDE's Serial Monitor, send a V followed by return. You should see some version information returned.
Wire up the Nano as shown in the schematic / wiring diagram in the Docs directory. The only additional components are wires and an appropriate connector for your Morse key / paddle, e.g. a 3.5mm stereo jack socket.
For a Morse key, the tip goes to Arduino pin D5. For a paddle, dit goes to D5, dah goes to D4. (maybe, haven't tested that yet!)
Connect a Morse key / paddle. Tapping the key / paddle should yield single bytes on the Serial Monitor.
The source is split into the following directories:
Libraries - third-party libraries I've used in this project
Docs - pinouts and schematic diagrams.
This directory - the main code, and SCoop library.
This code is released under the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0.html. (C) 2020-2021 Matt Gumbley, DevZendo.org
This project would not have been possible without the hard work and inspiration of many individuals.
Notably, thanks to:
SCoop - Simple Cooperative Scheduler for Arduino and Teensy ARM and AVR https://github.com/fabriceo/SCoop
TBC