Author: John
How precise is a circa 1999 Garmin eTrex?
This is the first of the tests I’m doing to compare GPS/GNSS receivers. I got my first GPS unit, a Garmin eTrex in 2001 and I used it to Geocache. It’s sat unused for over 12 years, but…
Read More »Measuring GPS (GNSS) Accuracy and Precision
With the recent technological advancements, I’ve recently become interested in RTK GPS and decided it would be fun to compare all the different GPS/GNSS (Global Navigation Satellite System) receivers I own. I ultimately plan to see how they…
Read More »Powering and Grounding 1Wire DS18B20 with Digital IO Pins
Sometimes you find yourself in a situation where your Micro-controller has plenty of spare IO, very little power & ground connectors, and you want to add a 1Wire DS18B20 device as tidily as possible. The classic Dallas 1Wire…
Read More »Converting the pinout on a Tycon POE-INJ-1000-DINx PoE injector
Tycon power sell a relatively cheap high power gigabit PoE injector. The high power bit means that it inserts power on all four ethernet pairs. This is important when using PoE to power devices over long cable lengths,…
Read More »Using LetsEncrypt with Ubiquiti Unifi Video server
I’ve spent a lot of time scratching my head trying to get LetsEncrypt, or more accurately certbot working with Ubiquiti UniFi Video server, especially auto-renewing the certificate every month or so. I found two posts on the Ubiquiti…
Read More »SQL Tips – List of Countries (2018 revision)
Over nine years ago, I published a SQL and tab delimited list of countries sourced from Wikipedia and ISO. After numerous comments about it being out of date, here is an updated version….. The data was sourced from…
Read More »I’m still here
To answer all those messages… Yes, I am still alive! Watch this space, more posts to come very soon
Read More »Cheese fridge repairs
My cheese fridge was partially destroyed at the start of July. A car crashed into a power pole carrying both a 22kv distribution line and the 230v line for our house. They . touched . briefly It turns…
Read More »Setting up a CA SSL certificate in hMailServer
I’m a big fan of hMailServer, but the documentation for setting up SSL certificates and the certification chain is a bit lacking. The easiest way to check if hMailServer is setup correctly is to use OpenSSL. openssl.exe s_client…
Read More »1,500,000,000 the Epochening
Don’t forget that at 2:40am, 14 July 2017 (UTC) the Linux epoch will hit 1,500,000,000 (1.5 Gigaseconds). Visit https://www.john.geek.nz/epoch to watch the excitement! It hit 1,000,000,000 back in September 2001 and it won’t hit 2,000,000,000 until May 2033.
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