today's leftovers

• RFID and Raspberry PI: RC522 wiring and code with Python

  RFID systems are common in our lives as they are widely used to secure access, monitor objects’ positions (IoT) and a lot of other applications. Their technology is so mature that they are today reliable components and easy to use. The RC522 module with Raspberry PI can bring to your hands this technology with a few steps and a cheap budget In this tutorial, I’m going to show you how to connect and configure a Raspberry PI with an RFID RC522 module, using Python.

• This DIY basketball scoreboard looks and sounds like the real thing | Arduino Blog

  Inspired by his time as a scorekeeper in elementary school, now-high schooler Collin Wentzien wanted to recreate this setup by building a DIY scoreboard several years ago. His idea involved making a bright display composed of several seven-segment displays that could all be controlled by an external device in order to set scores, start/stop the clock, and more. The controller sits inside of a small custom box that contains a pair of button matrices, which either increment the score for the home/guest team or provides a keypad that can be used to enter numerical values and set the clock. Below its custom PCB is an Arduino Mega 2560 that handles all of the button inputs, along with a character LCD for showing what has been entered and an nRF24L01+ wireless transceiver for sending new data to the scoreboard.

• What Metric to Use When Benchmarking?

  What is the right metric to use when measuring a program's performance? There are various possibilities, from memory usage to branch prediction hit rates, but I'm going to pick on two that I see widely used: CPU instructions executed (what modern CPUs call "instructions retired") and wall-clock time (i.e. "how much time has elapsed in the real world?"). In this post, I'm going to try and compare both, showing why each has fundamental weaknesses, before explaining why I use each in different circumstances.

• Linux Weekly Roundup #189

  Welcome to this week's Linux Weekly Roundup. We had a full week in the world of Linux releases with ArcoLinux 22.07.03, Nitrux OS 20220629, Pisi Linux 2.3, and Condres OS 1.0.

• What if WordPress Didn’t Exist?

  WordPress powers like 40% of the internet or something, so I don’t think it will be going anywhere anytime soon. But what if Matt and the team decide to go in a direction I don’t agree with, like Ghost have? My knee-jerk reaction would be to go back to Jekyll – it’s light and I know it fairly well. But like I said, managing content is painful and Ruby can be a bit of pig to manage.

Programming Leftovers

• A Major Contribution to Learning R

  Prominent statistician Frank Harrell has come out with a radically new R tutorial, rflow. The name is short for “R workflow,” but I call it “R in a box” –everything one needs for beginning serious usage of R, starting from little or no background. By serious usage I mean real applications in which the user has a substantial computational need. This could be a grad student researcher, a person who needs to write data reports for her job, or simply a person who is doing personal analysis such as stock picking. Like other tutorials/books, rflow covers data manipulation, generation of tables and graphics, etc. But UNLIKE many others, rflow empowers the user to handle general issues as they inevitably pop up, as opposed to just teaching a few basic, largely ungeneralizable operations. I’ve criticized the tidyverse in particular for that latter problem, but really no tutorial, including my own, has this key “R in a box” quality.

• The deep learning obesity crisis - Vincent Lequertier's blog

  Deep learning have made dramatic improvements over the last decades. Part of this is attributed to improved methods that allowed training wider and deeper neural networks. This can also be attributed to better hardware, as well as the development of techniques to use this hardware efficiently. All of this leads to neural networks that grow exponentially in size. But is continuing down this path the best avenue for success? Deep learning models have gotten bigger and bigger. The figure below shows the accuracy of convolutional neural networks (left) and the size and number of parameters used for the Imagenet competition (right). While the accuracy is increasing and reaching impressive levels, the models get both bigger and use more and more resources. In Schwartz et al., 2020, as a result of rewarding more accuracy than efficiency, it is stated that the amount of compute have increased 300k-fold in 6 years which implies environmental costs as well as increasing the barrier to entry in the field.

• Mint: A New Programming Language for Building Single Page Apps (SPAs)

  Mint is a refreshing programming language for the front-end web development. It is developed and maintained by a large community of experienced developers.

• Understanding Have I Been Pwned's Use of SHA-1 and k-Anonymity

  Four and a half years ago now, I rolled out version 2 of HIBP's Pwned Passwords that implemented a really cool k-anonymity model courtesy of the brains at Cloudflare. Later in 2018, I did the same thing with the email address search feature used by Mozilla, 1Password and a handful of other paying subscribers. It works beautifully; it's ridiculously fast, efficient and above all, anonymous.

today's howtos

• How to Select All in Vim / Vi

  Knowing how to select all content in Vim or the Vi editor enables you to complete routines like copying and pasting in Linux quickly. The process can be tricky if you don’t understand how to use the editors properly or bind keys. For instance, you can select all in Vim/Vi by combining the gg, V, and G keys. ggVG Before that, you must be in the normal mode and know what the groups of keys mean or do. This article takes you through Vim/Vi modes, commands, and key bindings. You will find it simpler to select and use file contents with this knowledge.

• How to Use Restic to Backup and Restore Data in Linux

  Restic is an open-source, secure, and cross-platform backup program. Using Restic we can store multiple versions of files and directories in an encrypted repository. Restic can be used to back up data to an external device or to cloud storage. Restic encrypts data with the AES-256 in counter mode and then authenticates it using the Poly1305-AES cryptographic message authentication code. This way Restic guarantees confidentiality and data integrity by utilizing cryptography. Restic does incremental backups which makes it easier and faster compared to some other backup programs. What this means is that it stores a base backup image and then for each subsequent backup, it stores the difference between that base image and the source machine. This leads to increased backup speed as only the modified data is backed up. It also consumes less backup space.

• How to install PulseEffects on a Chromebook

  Today we are looking at how to install PulseEffects on a Chromebook. Please follow the video/audio guide as a tutorial where we explain the process step by step and use the commands below.

• Rubenerd: Basic fix between pf tables and macros on FreeBSD

  I worked with a FreeBSD client this morning who’d messed up the pf rules on their VM firewall, and wanted to know how to fix them.