We’ve been going on at length in this space about the death spiral that AM radio seems to be in, particularly in the automotive setting. Car makers have begun the process of phasing AM out of their infotainment systems, ostensibly due to its essential incompatibility with the electronics in newer vehicles, especially EVs. That argument always seemed a little specious to us, since the US has an entire bureaucracy dedicated to making sure everyone works and plays well with each other on the electromagnetic spectrum. The effort to drop AM resulted in pushback from US lawmakers, who threatened legislation to ensure every vehicle has the ability to receive AM broadcasts, on the grounds of its utility in a crisis and that we’ve spent billions ensuring that 80% of the population is within range of an AM station.
fireworks28 Articles
Seeing Fireworks In A Different Light
If you’re worried that [Roman Dvořák]’s spectroscopic analysis of fireworks is going to ruin New Year’s Eve or the Fourth of July, relax — the science of this build only adds to the fun.
Not that there’s nothing to worry about with fireworks, of course; there are plenty of nasty chemicals in there, and we can say from first-hand experience that getting hit in the face and chest with shrapnel from a shell is an unpleasant experience. [Roman]’s goal with this experiment is pretty simple: to see if it’s possible to cobble together a spectrograph to identify the elements that light up the sky during a pyrotechnic display. The camera rig was mainly assembled from readily available gear, including a Chronos monochrome high-speed camera and a 500-mm telescopic lens. A 100 line/mm grating was attached between the lens and the camera, a finding scope was attached, and the whole thing went onto a sturdy tripod.
From a perch above Prague on New Year’s Eve, [Roman] collected a ton of images in RAW12 format. The files were converted to TIFFs by a Python script and converted to video by FFmpeg. Frames with good spectra were selected for analysis using a Jupyter Notebook project. Spectra were selected by moving the cursor across the image using slider controls, converting pixel positions into wavelengths.
There are some optical improvements [Roman] would like to make, especially in aiming and focusing the camera; as he says, the dynamic and unpredictable nature of fireworks makes them difficult to photograph. As for identifying elements in the spectra, that’s on the to-do list until he can find a library of spectra to use. Or, there’s always DIY Raman spectroscopy. Continue reading “Seeing Fireworks In A Different Light”
1D Fireworks Are Nice And Quiet
Maybe you do it out of respect for the dogs and parents of young children in the neighborhood. Or maybe you do it because they’re harmful to the environment, or just because it’s too darn cold outside. Whatever your reasoning for not setting off fireworks, don’t fret — you can probably put together your own silent one-dimensional “fireworks” display from what you’ve got in the parts bin.
[Daniel Westhof]’s design is simple, requiring little more than a Wemos D1 Mini and a strip of WS2812 LEDs. Once activated, a red rocket shoots up from the ground and detonates, sending lights in both directions on the strip to imitate the bombs bursting in air. It’s controlled with a small push button switch, and there’s a deliciously large red LED indicator that shows the thing is ready for detonation.
You might be surprised to find that there’s a wide array of 1D gaming and animation projects out there, many of which made possible by the ubiquitous addressable RGB LED strip. We’ve seen a dungeon crawler, at least two different versions of the classic PONG, and even the makings of a simplified Wolfenstein.
Localizing Fireworks Launches With A Raspberry Pi
If you have multiple microphones in known locations, and can determine the time a sound arrives at each one, you can actually determine the location that sound is coming from. This technique is referred to as sound localization via time difference of arrival. [Kim Hendrikse] decided to put the technique to good use to track down the location of illicit fireworks launches.
The build is based on the Raspberry Pi, with [Kim] developing an “autonomous recording unit” complete with GPS module for determining their location and keeping everything time synchronized. By deploying a number of these units, spread out over some distance, it’s possible to localize loud sounds based on the time stamps they show up in the recording on each unit.
Early testing took place with an air horn and four recording units. [Kim] found that the technique works best for sounds made within the polygon. Determining the location was achieved with a sound investigation tool called Raven Lite, developed by Cornell University. The process is very manual, involving hunting for peaks in sound files, but we’d love to see a version that automated comparing sound peaks across many disparate recording units. In any case, it worked incredibly well for [Kim] in practice. Later testing with friends and a network of six recorders spread over Limburg, Netherlands, [Kim] was later able to localize fireworks launches with an accuracy down to a few meters.
Similar techniques are used to locate gunshots, and can work well with pretty much any loud noise that’s heard over a great distance. If you’ve been using your hacker skills to do similar investigative work, don’t hesitate to let us know on the tipsline!
Hackaday Links: July 9, 2023
Good news this week from Mars, where Ingenuity finally managed to check in with its controllers after a long silence. The plucky helicopter went silent just after nailing the landing on its 52nd flight back on April 26, and hasn’t been heard from since. Mission planners speculated that Ingenuity, which needs to link to the Perseverance rover to transmit its data, landed in a place where terrain features were blocking line-of-sight between the two. So they weren’t overly concerned about the blackout, but still, one likes to keep in touch with such an irreplaceable asset. The silence was broken last week when Perseverance finally made it to higher ground, allowing the helicopter to link up and dump the data from the last flight. The goal going forward is to keep Ingenuity moving ahead of the rover, acting as a scout for interesting places to explore, which makes it possible that we’ll see more comms blackouts. Ingenuity may be more than ten-fold over the number of flights that were planned, but that doesn’t mean it’s ready for retirement quite yet.
Launching Fireworks With Raspberry Pi This Fourth Of July
It’s that time of year again in the United States, and the skies will soon be alight with pyrotechnic displays, both professional and amateur. Amazing fireworks are freely available, sometimes legally, sometimes not. For the enthusiasts that put on homebrew displays, though, the choice between watching your handiwork or paying attention to what you’re doing while running the show is a tough one. This Raspberry Pi fireworks show controller aims to fix that problem.
[netmagi] claims his yearly display is a modest affair, but this controller can address 24 channels, which would be a pretty big show in any neighborhood. Living inside an old wine box is a Raspberry Pi 3B+ and three 8-channel relay boards. Half of the relays are connected directly to breakouts on the end of a long wire that connect to the electric matches used to trigger the fireworks, while the rest of the contacts are connected to a wireless controller. The front panel sports a key switch for safety and a retro analog meter for keeping tabs on the sealed lead-acid battery that powers everything. [netmagi] even set the Pi up with WiFi so he can trigger the show from his phone, letting him watch the wonder unfold overhead. A few test shots are shown in the video below.
As much as we appreciate the DIY spirit, it goes without saying that some things are best left to the pros, and pyrotechnics is probably one of those things. Ever wonder how said pros pull it off? Here’s a behind-the-scenes look.
Continue reading “Launching Fireworks With Raspberry Pi This Fourth Of July”
Hackaday Prize Entry: Pyrotechnics Sequencer With Wireless Control
[visualkev]’s friend was putting on his own fireworks show by lighting each one in turn, then running away. It occurred to [visualkev] that his friend wasn’t really enjoying the show himself because he was ducking for cover instead of watching the fun. Plus, it was kind of dangerous. Accordingly, he applied his hacker skills to the challenge by creating a custom fireworks sequencer.
He used a custom PCB from OSH Park with an ATMega328P controlling eight TPIC6C595 8-bit shift registers, which in turn trip the 64 relays connecting to the fireworks. A 5V regulator supplies the project from 5 5AA batteries, and he kept the wires neat with 8-wire ribbon cables.
Starting the sequence is a generic wireless remote — a cheapie from Walmart — allowing [visualkev]’s friend can launch the fireworks with one hand while working the barbecue tongs with the other.