Introduction – how’s it going This post will cover the logging of data in Cacti using non SNMP/WMI sources. We’ll gather local RPi information and plot it in Cacti. Then we will go through the procedures to gather data from the internet and process it into Cacti. This is an expansion of the NOAA XML file processing done in an earlier post. Purpose – having a reference can give you an idea of were you’re going Cacti is a multi…
Introduction – a practical need I want to automate the task of changing when my house heater turns on or off. You’re probably thinking, use a thermostat. That works with conventional forced air heating. We use radiant floor heating that is from the hot water supply for the home. There is a wider hysteresis. It’s more likely the warmth effects will last longer after the conventional thermostat triggers off. This is also the case when it needs to heat the…
Introduction – There is more to the picture for the eye In the last post we extracted data from images and processed it. In this post we will cover the topic of image manipulation based on external data. This is useful because it allows us to combine data sets into a single point of observation. I’ll go through how to take an image and convert it based on variable conditions. I’ll also cover how to overlay text data into an…
Introduction – processing images with ImageMagick I first posted about ImageMagick in early June, last year. Then late November, I covered the steps to install it and use it on RPi. The features of ImageMagick are fairly extensive, I won’t go into all of them here. As a guide, I recommend Michael Still’s book titled “The Definitive Guide to ImageMagick” through APress publishing. For additional information, you may want to look at Sohail Salehi’s book titled “ImageMagick Tricks” from Packt Publishing. ImageMagick is defined on…