Cool Things to Do With Cheap Laser Modules

When I was sleeping on the streets, in the rainy season, I used to enjoy watching the reflection of sodium vapour lamps in the rainwater as it fell on some ceramic paving. The angle of incidence of the street-light on the paving was such that the shadow it cast on the wall showed interference, and those patterns were affected as each drop of rain splashed down. I thought of making a garden sculpture that showed these patterns on a wall, reflected from a fountain or something. See Simone Geirtz - Making a Lamp.


 Subscribe to Zenodilodon.

Comments

Post a Comment

Popular posts from this blog

Steven Johnson - So You Think You Know How to Take Derivatives?

Image
A derivative is linearisation, and differential calculus is essentially linear algebra, ...  See  Freya Holmér - Why Can't You Multiply Vectors?  and  Freya Holmér on Continuity of Splines . See also the MIT OCW page:  Matrix Calculus For Machine Learning And Beyond  (Alan Edelman, Steven G. Johnson) Subscribe to The Julia Programming Language . Alan Edelman talking about expressing mathematics as computer code. The idea is that you can use computer languages to communicate mathematical ideas precisely to other people. See my comments about functional programming languages here:  https://prooftoys.org/ian-grant/hm/ Subscribe to TEDx Talks .
Read more

Hitachi HD44780U LCD Display Fonts

Image
I finally got the bit-mapped fonts from the Hitachi "1602" display :  Here's some JavaScript: const HD44780U01ASCII=[ [],[],[],[],[],[],[],[],[],[],[],[],[],[],[],[], [],[],[],[],[],[],[],[],[],[],[],[],[],[],[],[], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ], [4, 4, 4, 4, 0, 0, 4, 0, 0, 0, ], [10, 10, 10, 0, 0, 0, 0, 0, 0, 0, ], [10, 10, 31, 10, 31, 10, 10, 0, 0, 0, ], [4, 15, 20, 14, 5, 30, 4, 0, 0, 0, ], [24, 25, 2, 4, 8, 19, 3, 0, 0, 0, ], [12, 18, 20, 8, 21, 18, 13, 0, 0, 0, ], [12, 4, 8, 0, 0, 0, 0, 0, 0, 0, ], [2, 4, 8, 8, 8, 4, 2, 0, 0, 0, ], [8, 4, 2, 2, 2, 4, 8, 0, 0, 0, ], [0, 4, 21, 14, 21, 4, 0, 0, 0, 0, ], [0, 4, 4, 31, 4, 4, 0, 0, 0, 0, ], [0, 0, 0, 0, 12, 4, 8, 0, 0, 0, ], [0, 0, 0, 31, 0, 0, 0, 0, 0, 0, ], [0, 0, 0, 0, 0, 12, 12, 0, 0, 0, ], [0, 1, 2, 4, 8, 16, 0, 0, 0, 0, ], [14, 17, 19, 21, 25, 17, 14, 0, 0, 0, ], [4, 12, 4, 4, 4, 4, 14, 0, 0, 0, ], [14, 17, 1, 2, 4, 8, 31, 0, 0, 0, ], [31, 2, 4, 2, 1, 17, 14, 0, 0, 0, ], [2, 6, 10, 18, 31, 2, 2, 0, 0,...
Read more

Using Pipewire to Make A Music Synthesizer

Image
Illustration from Project Gutenberg's The Tenniel Illustrations for Carroll's Alice in Wonderland by Sir John Tenniel. Thinking about the linux desktop audio problem: I'm not the only one who finds this weird: https://t.co/b2BZMiak07 — eternal Doorman (@IanANGrant66) May 17, 2025  I noticed that if you change the volume using the Gnome volume keys it changes it in jumps. Usually you don't notice, but if you play a pure sine tone then you can easily hear the distortion. If you want to play with pipewire from C on Ubuntu 24.04 then it's really easy. The pipewire tutorials and examples can be compiled and run if you just first install the pipewire-0.3-dev package with sudo apt install libpipewire-0.3-dev But the API is sooo far away from pluggable, typed streams that I find it quite depressing. Is it because nobody understands the necessary type system . See  Programming Channel Processes and Alice's Adventures In The Wonderland Wide Web . [Update: y...
Read more