MorseMaster II shaped code
How many zillions of 555 based code practice oscillators are there beeping away ? Probably quite a few - I remembered that my MorseMaster II project has one, previously mentioned here: https://wb9kzy.blogspot.com/2026/02/bad-cap.html But the original MorseMaster II design by Mike, KJ4LN cleverly upgraded the 555, adding shaping to the waveform and RC filtering: So I thought about adding those circuits to my MorseMaster. One interesting note: the 555 in the Morsemaster II runs continuously so really the circuits add keying, shaping and filtering. The steady 555 current doesn't matter that much considering the power used by the microcontroller is fairly high. First, using a solderless breadboard, here are the full pulse and the zoom in on ramp up / down waveforms all at the the collector of Q4: . 4 ms rise time 8 ms fall time Next, here is the shaped square wave, with rise and fall zooms: That's about as far as I gotten so far, I'll add the filter and LM380...