Author: richardvk

Adding a custom MySQL prompt

September 1, 2018 by richardvk

Filed under Databases

Last modified September 1, 2018

I often work on multiple database instances at the same time. For example, i might be comparing table definitions between a development and production server, or if using a cluster like Percona XtraDB Cluster, you may have sessions open to each of three (or more) of the node servers at the same time to check their synchronisation statuses. Whatever the use case, its extremely helpful …

Sending Pushover notifications via PERL

April 23, 2018 by richardvk

Filed under Monitoring

Last modified April 23, 2018

#!/usr/bin/perl use strict; use LWP::UserAgent; my $s = scalar(@ARGV); exit if ($s!=2); my ($message, $recipient_list) = @ARGV; my @recipients = split(‘,’,$recipient_list); foreach my $recipient(@recipients) { _send_msg($message, $recipient); } sub _send_msg($message, $recipient) { my ($m, $r) = @_; print “Sending: ‘$m’, $r\n”; LWP::UserAgent->new()->post( “”, [ “token” => “<your_token>”, “user” => $r, “message” => $m ]); }

ESP8266 Wifi Repeater and automesh

February 15, 2018 by richardvk

Filed under ESP8266

Last modified February 18, 2018

I recently discovered this video on YouTube and thought it looked like a really interesting idea! Especially since I recently bought a pack of 10 NodeMCU boards for about $27 – just because it was so cheap, not because i actually needed 10 of them! – and was wondering what the heck I was going to do with all these things! I own a commercial …

Notes from Week 06/2018 (February 5-11 2018)

February 12, 2018 by richardvk

Filed under Blog

Last modified February 12, 2018

Good reads: Computing at the Edge of IoT: A very good description of how and why some of the cloud processing needs to move out the cloud and to the edge to accommodate not only the scale of IoT, but also other factors. Notwithstanding the fact that the author is employed by Google, all the Google Cloud services and Android references can effectively be replaced …

The Little Buddy Talker – Arduino Compatible Speech Chip Set (Kickstarter)

February 1, 2018 by richardvk

Filed under Crowdfunding

Last modified February 1, 2018

Tagline:Ā Small, versatile, fun, and inexpensive! Use the 254 word library to bring speech to your Arduino projects! Speak, Arduino, Speak! What would the maker world be without the legendary ESP8266 wifi chip? Whether its the ‘original’ Wemos D1 (a standard Arduino form factor board but with built in WiFi) or its baby brother, the D1 mini, or the NodeMCU’s, these chips have revolutionised the makerspace …

MySQLdump, useful tips and summary notes

February 1, 2018 by richardvk

Filed under Databases

Last modified February 5, 2018

Dumping databases for backups is absolutely essential, but like all things in life, you can never get everything you want – there are tradeoffs….   The most important points probably when dumping databases are: We want it to be as quick as possible We want it to have as little as impact as possible (preferably NO impact) on users experience We want a backup that …

Snapmaker : The All-Metal 3D Printer (Kickstarter)

January 30, 2018 by richardvk

Filed under Crowdfunding

Last modified January 30, 2018

I have never touched a 3D printer in my life. But there are a million things I would love to produce, if only I knew how. This tool promises 3 functions in 1: 3D printing Laser engraving CNC carving My mind is running wild already!! Can wait until this arrives, it promises to be game changing šŸ™‚ Check out more on the Kickstarter campaign hereĀ on …

Nixie Tube SHIELD for Arduino (Indiegogo)

January 30, 2018 by richardvk

Filed under Crowdfunding

Last modified January 31, 2018

Project tagline: With Nixie Tube SHIELD for Arduino you can bring to life any Nixie Tubes and use with your projects! I love my Nixies! I currently have a bunch of IN12B Nixie tubes I bought a few years ago. To date, for testing, I have used a 12v->170v step-up converter to power them, and drove the outputs via some old Russian BCD chips. The …

Get an email notification when someone becomes root (sudo’s) on a Linux server

January 26, 2018 by richardvk

Filed under Linux

Last modified January 31, 2018

I have found this very useful to keep track of when other team members become root on one of our core infrastructure servers. I dont want a notification when I (username=’richard’) log in though, so I exclude myself with a simple ‘if’. Add this to roots ‘.bashrc’ file: WHO=`who am i | cut -d ” ” -f1` if [ “$WHO” != “richard” ]; then echo …

BootStrength: a Bootstrap styled javascript password strength meter

December 18, 2015 by richardvk

Filed under Web Development

Last modified January 31, 2018

A while back I had a requirement to not only give a visual indication of password strength, as a user was entering it in a standard HTLM form password input, but additionally I needed the ability to define what exactly was meant by ‘strength’. For some requirements a minimum length and a combination of alpha-numerics might suffice, but for other requirements we might need to …