Sidney San Martín s4y

How to set up a fresh Pi SD card real fast

Download an OS image from https://www.raspberrypi.com/software/operating-systems/. I like starting with 64 bit lite! It's small and you can always add a desktop later.
Plug the SD card into your mac and use diskutil list to find it. Size is a good trick for picking the right one!
sudo chown "$(whoami)" /dev/rdiskX (where X is the number of the SD card).
xzcat ~/Downloads/2025-10-01-raspios-trixie-arm64-lite.img.xz | dd of=/dev/rdiskX bs=4M

The following FFmpeg filter will populate the red channel of a video with the hue of the video:

geq=r='if(eq(st(3,max(max(st(0,r(X,Y)/255),st(1,g(X,Y)/255)),st(2,b(X,Y)/255))),ld(0)),(ld(1)-ld(2))/(ld(3)-min(ld(1),ld(2))),if(eq(ld(3),ld(1)),2+(ld(2)-ld(0))/(ld(3)-min(ld(0),ld(2))),4+(ld(0)-ld(1))/(ld(3)-min(ld(0),ld(1)))))*42*ld(3)'

You can make a grayscale video by appending the following:

 , geq=g='r(X,Y)':b='r(X,Y)'

	config_version = 1

	[system]
	hostname = "raspberrypi"

	[user]
	name = "pi"
	password = "raspberry"

	[ssh]

	#!/usr/bin/env python3

	# This is a proof of concept for controlling a LaserCube
	# (https://www.laseros.com) over the network. RUNNING THIS CODE WITH A REAL
	# LASERCUBE CAN BE PHYSICALLY DANGEROUS. PLEASE BE CAREFUL, AND, IF IN DOUBT,
	# USE THE SAFETY LENS!

	# Copyright 2021 Sidney San Martín
	#
	# Permission to use, copy, modify, and/or distribute this software for any

	// https://stackoverflow.com/questions/15095909/from-rgb-to-hsv-in-opengl-glsl
	vec3 rgb2hsv(vec3 c) {
	vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
	vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
	vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));

	float d = q.x - min(q.w, q.y);
	float e = 1.0e-10;
	return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
	}

	<!DOCTYPE html>
	<meta name=viewport content="width=device-width">
	<style>
	html, body, #app {
	height: 100%;
	}

	html {
	background: rgb(220, 0, 220, 1);
	}

	:fn sin 1
	:fn cos 1
	:fn vec2.1 1
	:fn vec2 2
	:fn vec3 3
	:fn vec3.1 1
	:fn vec3.2 2
	:fn vec4.1 1
	:fn vec4.2 2
	:fn vec4.3 3

	tell application "Safari"
	repeat
	repeat with theWindow in every window
	repeat with theTab in every tab of theWindow
	if name of theTab contains "Reserve a Time Slot" then
	set checkoutWindow to theWindow
	set checkoutTab to theTab
	end if
	end repeat
	end repeat

	# IP_ADDRESS_HERE -> 192.168…
	openssl req -newkey rsa:2048 -nodes -keyout key.pem -x509 -days 365 -out cert.pem -reqexts SAN -extensions SAN -config <(cat /System/Library/OpenSSL/openssl.cnf <(printf '[SAN]\nsubjectAltName=IP:IP_ADDRESS_HERE\nextendedKeyUsage=serverAuth\nbasicConstraints=critical,CA:TRUE'))

	# coding: utf-8

	import scene
	import motion

	preamble = """
	precision highp float;
	varying vec2 v_tex_coord;
	uniform vec2 u_sprite_size;
	uniform sampler2D u_texture;