https://speakerdeck.com/electricshaman 2017-09-11 16:51:58 -0400 In this talk, Jeff will pull back the curtain on `gen_statem` and provide a useful reference for how and when to use it and why the apparent complexity might be worth it. What are its strengths and weaknesses? Is there anything `gen_statem` can do that `GenServer` can't? In this talk, Jeff will explore these questions while providing some guidance and clarity on this mysterious behaviour available since the release of OTP 19. In this talk, Jeff will pull back the curtain on `gen_statem` and provide a useful reference for how and when to use it and why the apparent complexity might be worth it. What are its strengths and weaknesses? Is there anything `gen_statem` can do that `GenServer` can't? In this talk, Jeff will explore these questions while providing some guidance and clarity on this mysterious behaviour available since the release of OTP 19. Thu, 28 Feb 2019 00:00:00 -0500 https://speakerdeck.com/electricshaman/pretty-state-machine https://speakerdeck.com/electricshaman/pretty-state-machine As part of the next generation air traffic control system, regulators in the United States and abroad will require most aircraft to be equipped with avionics by 2020 that automatically broadcast identity, position, and velocity data at regular intervals using a standard radio messaging protocol. This technology, known as Automatic Dependent Surveillance Broadcast (ADS-B), is already in use by the majority of aircraft today and can easily be received on the ground by anyone using cheap Software Defined Radio (SDR) hardware purchased online. Because ADS-B messages can come from hundreds (if not thousands) of aircraft operating in the sky in parallel at any given time, Elixir is well suited to elegantly handle the problem of tracking them all concurrently in realtime. In this talk, we'll explore highly concurrent approaches to solving this problem using the tools and techniques offered by OTP and GenStage. We'll examine how SDR hardware support is provided using Nerves on an embedded Linux platform such as Raspberry Pi. Finally, we'll take a look at some ways we can visualize all of this flight activity on the web in realtime using Phoenix. Links Squitter app: https://github.com/electricshaman/squitter Parts List: https://www.dropbox.com/s/prkyoin528ylvcz/Squitter%20Parts%20List.pdf?dl=0 ADS-B on FlightAware: http://flightaware.com/adsb/ ADS-B Decoding Guide: https://adsb-decode-guide.readthedocs.io/en/latest/index.html Custom Nerves System for SDR on Raspberry Pi 3: https://hex.pm/packages/nerves_system_rpi3_sdr LeafletJS: http://leafletjs.com/ Hobbyist's Guide to the RTL-SDR: https://www.amazon.com/Hobbyists-Guide-RTL-SDR-Software-Defined/dp/1514716690 RTL-SDR Amazon.ca: https://www.amazon.ca/gp/product/B01GDN1T4S RTL-SDR Amazon.com: https://www.amazon.com/dp/B01GDN1T4S As part of the next generation air traffic control system, regulators in the United States and abroad will require most aircraft to be equipped with avionics by 2020 that automatically broadcast identity, position, and velocity data at regular intervals using a standard radio messaging protocol. This technology, known as Automatic Dependent Surveillance Broadcast (ADS-B), is already in use by the majority of aircraft today and can easily be received on the ground by anyone using cheap Software Defined Radio (SDR) hardware purchased online. Because ADS-B messages can come from hundreds (if not thousands) of aircraft operating in the sky in parallel at any given time, Elixir is well suited to elegantly handle the problem of tracking them all concurrently in realtime. In this talk, we'll explore highly concurrent approaches to solving this problem using the tools and techniques offered by OTP and GenStage. We'll examine how SDR hardware support is provided using Nerves on an embedded Linux platform such as Raspberry Pi. Finally, we'll take a look at some ways we can visualize all of this flight activity on the web in realtime using Phoenix. Links Squitter app: https://github.com/electricshaman/squitter Parts List: https://www.dropbox.com/s/prkyoin528ylvcz/Squitter%20Parts%20List.pdf?dl=0 ADS-B on FlightAware: http://flightaware.com/adsb/ ADS-B Decoding Guide: https://adsb-decode-guide.readthedocs.io/en/latest/index.html Custom Nerves System for SDR on Raspberry Pi 3: https://hex.pm/packages/nerves_system_rpi3_sdr LeafletJS: http://leafletjs.com/ Hobbyist's Guide to the RTL-SDR: https://www.amazon.com/Hobbyists-Guide-RTL-SDR-Software-Defined/dp/1514716690 RTL-SDR Amazon.ca: https://www.amazon.ca/gp/product/B01GDN1T4S RTL-SDR Amazon.com: https://www.amazon.com/dp/B01GDN1T4S Thu, 07 Sep 2017 00:00:00 -0400 https://speakerdeck.com/electricshaman/keep-an-eye-on-the-sky-with-nerves-and-phoenix https://speakerdeck.com/electricshaman/keep-an-eye-on-the-sky-with-nerves-and-phoenix