turingbirds

#!/bin/bash

# I do not want my screensaver to auto-activate after a timeout.
# For some reason, you *have* to select a nonzero, finite timeout value for xscreensaver (there's no "infinity").
# I only want my screensaver to active when I lock my system by pressing [Meta]+[L].
# This hotkey is set up to launch this script, which 
# - starts the xscreensaver daemon,
# - activates the screensaver (with lockscreen enabled),
# - waits for it to terminate (unlocking logs an "UNBLANK" event),
# - then kills the xscreensaver daemon.

turingbirds

Connect an IP camera via wired ethernet to an ethernet USB adapter to a Raspberry Pi

Connect the camera to the ethernet USB adapter via a CROSSOVER cable (or via an ethernet switch).

Install DHCP server:

sudo apt install isc-dhcp-server

turingbirds

From InkScape to DXF

1. Save in Inkscape as PDF

Draft your design in InkScape. If there's any text, convert it to a path before or during exporting (Path → Object to Path).

Save as PDF (tested PDF v1.5).

turingbirds

// Beveled wedge shape for OpenSCAD

// Written by C.A.P. Linssen <charl@itfromb.it>, Sept 2018

// This software is distributed under the "CC0 1.0 Universal (CC0 1.0)" license.

// You should have received a copy of the CC0 Public Domain Dedication along with this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.


// module bwedge

turingbirds

turingbirds

ltspice options for high precision simulation/data export

Uses backward Euler integration (maxord=1 option), which can be very slow.

Set maximum iteration counts: DC iteration count limit (itl1, default: 100), DC transfer curve iteration count limit (itl2, default: 50), and transient analysis time point iteration count limit (itl4, default: 10) [ltwiki]_.

.OPTIONS maxord=1

turingbirds

GPIB interfacing using Agilent 82357B on Ubuntu Linux

I initially had some problems installing on my laptop, so decided to boot Ubuntu 12.04.5 LTS, 3.13.0-32-generic from USB and work from there.

For an automated installation script, see gpib_install.sh (and gpib.conf) below. The rest of this document describes the actions of the installation script step-by-step.

First, get the packages that are necessary to support Python bindings:

turingbirds

turingbirds

/**
 * Compute the (Moore-Penrose) pseudo-inverse of a libgsl matrix in plain C.
 *
 * Compile uding:
 *
 *     gcc moore_penrose_pseudoinverse.c -lgsl -lblas
 *
 * Dependencies:
 * - libgsl (GNU Scientific Library) 
 * - libblas (Basic Linear Algebra Subprograms)

turingbirds

GNUPG CHEATSHEET

Setting up: key generation

This generates a public/private keypair.

$ gpg --gen-key
$ gpg --list-secret-keys