If you dig microcontrollers, and you like to dig into how they work, Elecia White wants to help you navigate their innermost secrets with the help of memory map files. In this refreshingly funny, but very deep keynote talk from the 2021 Hackaday Remoticon, Elecia guides us through one of the most intimidating artifacts of compilation — a file that lists where everything is being put in the microcontroller’s memory — and points out landmarks that help to make it more navigable.
And when you need to look into the map file, you probably really need to look into the map file. When your embedded widget mysteriously stops working, memory problems are some of the usual suspects. Maybe you ran out of RAM or flash storage space, maybe you have some odd hard fault and you want to know what part of the program is causing the trouble, or maybe you need to do some speed profiling to make it all run faster. In all of these cases, you get an absolute memory address. What lives there? Look it up in the memory map!
Gravity causes space-time to stretch — think back to the diagrams you’ve seen of a massive orb (a star or planet) sitting on a plane with grid lines drawn on it, the fabric of that plane being stretch downward from the mass of the orb. If you have two massive entities like black holes orbiting each other, they give off gravitational waves. When they collide and merge, they create a brief but very strong train of waves. Evidence of these events are what LIGO is looking for.
Rai Weiss had the idea to look for gravitational waves using laser interferometers in about 1967, but the available laser technology was too new to accomplish the feat. In an interferometer, a laser is shot through a beam splitter and one beam reflects out and back over a distance, and is then recombined with the other half using a photodetector to measure the intensity of light. As the distance in the long leg changes, the relative phase of the lasers shift, and the power detected will vary.
LIGO is not your desktop interferometer. It uses a 5 kW laser input. The 4 km legs of the interferometer bounce the light back and forth 1,000 times for an effective 4,000 km travel distance. These legs are kept under extreme vacuum and the mirrors are held exceptionally still. It’s worth it; the instrument can measure at a precision of 1/10,000 the diameter of a proton!
All talk and schedule information is available on the conference webpage, but here are the things you don’t want to miss (all times are Pacific time zone):
10:10 am | Keynote: Keith Thorne
5:25 pm | Keynote: Jeremy Fielding
6:25 pm | Hackaday Prize Ceremony
7:35pm | After party live set from DJ Jackalope — watch on Twitch, socialize on Discord
If you’re reading this post while the bits are still fresh, you’ve got about four hours until day two of Hackaday Remoticon 2021. You can feel the electricity in the air, right? We’ve got an absolutely stellar line-up this year: every talk is gonna be a good talk.
Friday was great fun, and you can still still rewind Friday’s live stream if you hurry. Otherwise, at 11:00 AM PST, we’ll start up day two with a keynote talk by Keith Thorne, who’s going to take us through all of the work, and hacks, that made the LIGO experiment the most sensitive instrument mankind has ever made. Bookending the talks, just before the Hackaday Prize announcement and after-party DJ Jackalope Live Set, Jeremy Fielding is going to be walking through everything about his robotic arm and what you need to know about anything that moves.
Watch some great talks, and then hang out with the presenters afterwards over on our Discord server. What more do you want on a Saturday?
We really don’t want you to miss out on anything, but in case you come late to the talks, you can rewind the live stream to catch up. After it’s all done, we’ll slice and dice up the talks so you can find them later. But if you miss out on the discussions, the chance to ask our speakers questions, and the pervasive Jolly Wrencher ambiance, you’ve just missed out. Join us live if you possibly can! We’d love to see you.
This article is part of the Hackaday.com newsletter, delivered every seven days for each of the last 200+ weeks. It also includes our favorite articles from the last seven days that you can see on the web version of the newsletter.
Want this type of article to hit your inbox every Friday morning? You should sign up!
All talk and schedule information is available on the conference webpage, but here are the things you don’t want to miss (all times are Pacific time zone):
With just a few days to go before the kickoff of the 2021 Hackaday Remoticon, we’re still working furiously behind the scenes to pack as much content as possible into the two day virtual event. In fact, there’s so much going on that we thought you’d appreciate getting a bit of a head start as far as planning your own personal course through the weekend goes. The event might be free, but that’s no reason not to squeeze as much out of it as you can.
Chat It Up on Discord
To begin with, you’re really going to want to join the official Hackaday Remoticon Discord server. We know some subset of the Hackaday readership would rather we used Matrix, or IRC, or maybe carefully modulated smoke signals; but at the end of the day, Discord has bubbled to the top as the defacto choice for this kind of thing. Give it a shot, you might actually like it.
The Discord server isn’t just a place for like-minded hackers to hang out and discuss the musical stylings of DJ Jackalope during the Saturday afterparty. It’s also how attendees can ask questions at the end of each presenter’s talk, as we’ll be turning off YouTube chat to keep things centralized. Even if you don’t plan on communicating with others (though you really should), the Discord server has an interactive schedule of events which will let you sign up to be notified when the talks you’ve selected are about to start, and we’ll be dropping important announcements and links in there as the event goes on.
Friday Bring-a-Hack on Gather Town
Like this, but with soldering irons.
Friday night ends with a Bring-a-Hack where attendees can show off whatever they’ve been working on using Gather. It’s a video chat platform inside a virtual 2D world that looks a bit like Legend of Zelda.
Using this virtual environment, you can easily drop into an ongoing video stream simply by walking up to the presenter. Once you’ve seen enough, just walk over to the next little cluster of users. The point is to recreate the experience of stopping by a crowded after party where everyone brought some hardware project along with them to get spark conversations. Space will be limited, with ticket holders and people in Discord getting the first dibs, so keep an eye on your inbox for information about how to join.
Of course this is not the only Friday evening activity. A few weeks ago we announced that Lewin Day will be hosting Hacker Trivia, giving our beloved commenters the chance to show off your unimpeachable knowledge of technology and Hackaday history. The Friday talk stream will dump immediately into trivia, but here’s the dedicated link if you want to set a reminder for yourself.
Try It, You’ll Like It!
It’s difficult, perhaps even impossible, to truly recreate the experience of going to an in-person hacker con. But with interactive events and the latest and greatest communication software, we’re hoping the 2021 Remoticon can get pretty close. All the pieces are in place, the only thing we need now is to have a whole bunch of excited hackers to join in and have a good time. Think you can help us out?
Remoticon is almost here, but by Saturday night it’ll be gone! The best sendoff we can think of is with a party, and DJ Jackalope is playing a live set to make that happen.
DJ Jackalope [Photo credit: Eli Omen Photography]We’ve been lucky to have live music from DJ Jackalope at numberous Hackaday Superconferences immediately after the Hackaday Prize ceremony. This year she reached out and suggested we continue the tradition, offering up her Twitch stream as the audio/video platform.
Everyone can enjoy the music, and still socialize via the Remoticon Discord server (invites will be sent out on Wednesday). Her set is scheduled to begin at 7:35 pm Pacific time on Saturday, November 20th.
But really you should plan to show up on the Remoticon live stream for Jeremy Fielding’s keynote at 5:25 pm followed by the Hackaday Prize ceremony at 6:25 pm — if not for the entire day. You can see why we need to cap the evening with a party!
All speaker and schedule info is available on the Remoticon website. Be sure to grab a free ticket; we’ll remind you about the live stream links, and that’s also how you’ll get access to Friday night’s Bring-a-hack. It bums us out that we can’t be together in person this year, but we’re going to do everything possible to enjoy each others’ company — come be a part that!
Friday was great fun, and you can still still rewind 
