Tag Archives | signal clock

Harmonic Difficulties With High-Speed Clock

Here I am chasing harmonics to drain them to ground. Literally. This is what I spent time doing today. Set up a draft schematic by happenstance with a strong drink, sunglasses, and music too loud.

See that square wave on the scope? That’s exactly what’s supposed to happen given by the drawing. Only, the waveform is somewhat messy. Too many long leads, unstable harmonics, spurious noises, and other monkey business artifacts going on.

On one hand, it is completely unclear what the specific contributing causes are. Yet, on the other hand, it’s perfectly clear what likely needs the most attention in terms of clean up and the use of the specified reference design’s filters. I can see what’s on the other side before the trial concept is finished.

Frequency Selectability Experiment with Arduino

By on in Arduino, Engineering, Research

Here is a short effort to program the control of crystal frequency output. 8MHz as the standing frequency with multipliers asserted one at a time.

This is an experiment to encode in binary a selectable output pulse rate from a 555 timer. Where selected GPIO pins become asserted to set the desired rate. Over an Uno connection with code, I set up a user interface to push millions of pulses through to a defined output. All in a single second each instance. Staring from a single pulse rate with multipliers of 16, 20, 32, and 40. Each one separately is chosen by simply entering what a user wants over a GUI interface.