What were some of the best posts on Hackaday last week? Elliot Williams and Al Williams decided there were too many to choose from, but they did take a sampling of the ones that caught their attention. This week’s picks were an eclectic mix of everything from metal casting and plasma cutters to radio astronomy and space telescope budgets. In between? Some basic circuit design, 3D printing, games, dogs, and software tools. Sound confusing? It won’t be, after you listen to this week’s podcast.
Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Download an audiophile-quality oxygen-free MP3 file here.
Episode 267 Show Notes:
News:
What’s that Sound?
- This week, both hosts knew what the sound was, so there was no live guessing. How about you? You could win a Hackaday podcast T-shirt. Fill out this form with your best guess!
Interesting Hacks of the Week:
- More Microwave Metal Casting
- Delays And Timers In LTSpice (no 555)
- Hacked Oscilloscope Plays Breakout, Hints At More
- Plasma Cutter On The Cheap Reviewed
- Still Up And Coming: Non-Planar FDM 3D Printing With 3 Or 6 Axes
- Getting Started With Radio Astronomy
Quick Hacks:
- Elliot’s Picks:
- Al’s Picks:
One of the points about why the 555 is so nice for home-brew synthesizers is that it’s a convenient schmitt-trigger block for oscillators – with the difference that you have the control input which allows you to trim the exact points where it switches. The lower trigger point is always half the control input, so you get well defined amplitudes instead of relying on some random logic chip’s manufacturing tolerances. It means you can do stuff with your signals, like adding and subtracting different waveforms with controllable results because you know the exact voltage offsets and everything.
Without it, you’d have to use some really esoteric chips or use a whole bunch of extra components to build the same thing using comparators. The control input has been used for a bunch of things, like battery float chargers with hysteresis, servo testers, signal decoders… the internals of a 555 just so happen to contain a common analog circuit design element that bends to a wide variety of purpose besides simple timers.
Although Shake the future’s example is just a hook in the guide video he also demonstrates making a egg holder with quite a complex voronoi structure to it.
There’s a special place in Hell for those programmers that wrote books of programs that my friends and I would spend hours upon hours typing in, failed to run, then went assiduously through each and every line again and again to make sure it was correct, only to have it kack, bork, and FAIL again and again. We had no idea that these charlatans were doing it on purpose. I mean, were they? Or were they just being sloppy? It’s not like you could go to the librarian and say, “Hey, maybe contact the publisher of this junk code and ask for the money back.”