I managed to find a bit of time today and breadboard up my little CW Beacon Keyer with my ATtiny13. The idea was to simply have the MCU drive a NPN transistor to switch a key line. So to that end, I simply wired up the circuit and then connected it to my CPO via the cable connected to my morse key. The video shows the result.
I'm pretty tickled, as this is my first MCU project so it was great to see it achieve what the intention was. It was also good that my CPO has an audio output that I can connect to my computer. With that, I ran FLdigi and it was great to see it had no trouble decoding the morse.
In the video you may also note the little SparkFun Breadboard Power Supply Stick I'm using. This provides a nice easy switchable 5V/3.3V and at the price was more convenient than me putting together a small board with just a 5V regulator. I ordered it from ProtoGear and had it on Friday just in time for the week-end. This will be rather useful for prototyping MCU and other TTL IC circuits on the breadboard.
Next step now is to draw up the simple circuit diagram and put together the full keyer – although that will also have an ISP connector. Might be harder to find time to achieve this next step though, but hey, at least the ideas there. 😉