CloudACM – Page 25 – Autonomous Computational Machines

RTL_433 SDR IoT Sniffer

November 30, 2018 Patrick Gilfeather

In this post I’ll be covering how to use SDR on Linux to capture data from wireless sensors using Benjamin Larrson’s RTL_433. I’ll start by covering the required install steps followed by some rudimentary examples. First you will need some kind of USB SDR hardware, this example we will be using the NooElec Nano. Here are the steps to install the RTL_433 software. Open a terminal window and enter in the following commands. sudo apt-get install libtool libusb-1.0.0-dev librtlsdr-dev rtl-sdr…

Capturing NOAA Satellite Images with SDR

October 31, 2018 Patrick Gilfeather

There are plenty of examples online (https://learn.adafruit.com/getting-started-with-rtl-sdr-and-sdr-sharp/overview) on how to receive images from NOAA satellites using SDR. This post will be about my experiences and ideas on how to improve the process I used. There are several items needed before having a finished image. These were the pieces used in my setup and some description about each. The first is the SDR hardware. Obviously this will be a requirement. It’s the typical DVB-T USB device most commonly used for SDR….

Cutting through the smoke with Retinex

September 7, 2018 Patrick Gilfeather

This year, most of August was unfit for bike riding due to wildfire smoke in the air. There was a 10 day stretch where the visibility scale reached zero. Standing on the shores at Shilshole, the smoke was so thick that land wasn’t visible across the Puget Sound. I wondered if land was still visible from a digital camera, even though I couldn’t see it. There is an imaging processing technique call Retinex that is used to enhance the dynamic…