OverviewThe Morse Keyboard is based around an ATMEGA168 microcontroller. The V-USB library is used to provide direct control of USB, eliminating the need for any other active components. A dual 7 segment display is also attached to the IO pins. Also, the Morse key and an additional button (to enable 'learning') is attached. There is really nothing else to it.
A regular USB socket is used to connect directly to a host.
The display is connected directly to some IO pins (via resistors).
The morse key connects via resistors to an IO pin.
A button on board is used to start 'learning' mode. When pressed, you enter the morse "-.-.-" and the firmware starts off with the speed you tapped this code with.
A mini speaker provides a side tone so you can hear what you're tapping. This can be disabled in software.
Parts listSubstitute values also listed where tolerance is not critical. Generally, only the crystal and zener diodes are critical, the rest can be 10-20% out.
PCBWhilst I'm no stranger to etching my own boards, I decided to go the easy route here, and used prototype board, soldering links between components. It's easily reproducible and still fits in the case.
ComponentsI elected to go small but not tiny. Most of the components are thru-hole, but a few are SMD, especially where adjacent pads are used. Resistors are 1/8W, which are much easier to fit on a small board than the larger 1/4w ones. And they were super-cheap from ebay for a bag of 5000 mixed types. The display was found from my junk box.
CaseThe case is an Eclipse mint tin. Like Altoids, these come in a peoper metal tin which lends itself well to this project. A little cutting with a mini dremel tool allows for all the various sockets, button and display.
Morse keyA real morse key. Accept no substitutes.
I can be reached at bb @ cactii . net
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