Free SSL certificates: use Let’s Encrypt with ISPConfig 3

View of the Chrome Certificate info pane for tomlankhorst.nlAs you might have noticed this site uses HTTPS. Obtaining SSL certificates was always a bit of a hassle. Finding a certificate authority, doing regular payment, renewals and installing the certificate on your server. Let’s Encrypt is an initiative to provide a better way of enabling encryption on websites. It is open, automated and above all: it offers free SSL certificates. Learn to use Let’s Encrypt on an ISPConfig 3.0 server.

I assume you already have an ISPConfig server up and running. You might have a number of sites that use plain HTTP of HTTPS that you want to secure with free SSL certificates. That’s good, we’re going to do the following:

  1. Obtaining certbot
  2. Requesting free SSL certificates
  3. Configuring SSL in ISPConfig
  4. Enabling automatic periodical renewal

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Matlab2Tikz: Perfect MATLAB Figures in LaTeX

MATLAB exported TikZ picture with custom stylingPapers and reports can’t do without both but integrating MATLAB figures in LaTeX is not so obvious. Different methods for exporting and including graphics exist but have various downsides like inconsistent scaling, wrong fonts and strange spacing. The best method I have come across so far is using matlab2tikz. It is a MATLAB script that is able to extract all relevant details out of a figure and convert it to PGFPlots (a LaTeX package).

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Estimating transmission time of a DecaWave DW1000 UWB transceiver frame

I like to share with you my C implementation for estimating the DecaWave transmission time because it has been created with help from the community and thus should be shared with it.

The DecaWave DW1000 is a versatile ultra-wideband transceiver that enables long range and fast communication. Due to its wide spectral width it is able to occupy a very narrow temporal with. Precise time-stamping then allows for estimating the time-of-flight which in turn can be used for determining the distance between two nodes.

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