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”

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Hackaday Links: October 1, 2023

We’ve devoted a fair amount of virtual ink here to casting shade at self-driving vehicles, especially lately with all the robo-taxi fiascos that seem to keep cropping up in cities serving as testbeds. It’s hard not to, especially when an entire fleet of taxis seems to spontaneously congregate at a single point, or all it takes to create gridlock is a couple of traffic cones. We know that these are essentially beta tests whose whole point is to find and fix points of failure before widespread deployment, and that any failure is likely to be very public and very costly. But there’s someone else in the self-driving vehicle business with way, WAY more to lose if something goes wrong but still seems to be nailing it every day. Of course, we’re talking about NASA and the Perseverance rover, which just completed a record drive across Jezero crater on autopilot. The 759-meter jaunt was completely planned by the onboard AutoNav system, which used the rover’s cameras and sensors to pick its way through a boulder-strewn field. Of course, the trip took six sols to complete, which probably would result in negative reviews for a robo-taxi on Earth, and then there’s the whole thing about NASA having a much bigger pot of money to draw from than any start-up could ever dream of. Still, it’d be nice to see some of the tech on Perseverance filtering down to Earth.

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High-Speed Camera Plus Lawnmower Equals Destructive Fun

I hate gratuitous destruction videos. You know, the ones that ask “what happens if we drop a red-hot ball of Plutonium onto a bag of Cheetos?” There’s a lot of smoke, flames and a big pile of ad revenue for the idiots behind it.

This destruction video is a little different, though. [Tesla 500] wanted to mount his high-speed camera onto a rotating blade, but without destroying the camera. In this video, he documents the somewhat nerve-wracking process of building a rig that spins a $3000 camera at several thousand revolutions per second minute. It’s all about the balance, about building a rig that balances the weight of the camera and the blade properly at high speed.

It took several attempts to get it right, and [Tesla 500] shows how he tested and refined each version, including shifting weights to account for the different densities of the camera itself, which has the heavy batteries at one side. And then he drops things onto the blade to see what they look like when sliced. Naturally.

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TI Chronos Watch Monitor Your Sleeping Infant

[Bill] wants a little piece of mind when his infant is sleeping in the other room. For him, the audio-only baby monitor could use some improvement. His proof-of-concept is that blue patch Velcroed on the swaddled infant. It monitors movement, orientation, and temperature and alerts you when something’s amiss.

Inside the pouch you’ll find a TI Chronos eZ430 wristwatch with the band removed. It’s a nice hardware choice because it includes an accelerometer, temperature sensor, and RF link to a USB dongle. [Bill’s] code sends a data packet to the PC about once a second. The PC watches to make sure there’s slight motion, indicating the baby is breathing. This part doesn’t work all that well as the accelerometer doesn’t pick up tiny movements all too well, but it does have potential. In the video after the break you can see the functions which make sure the baby doesn’t roll onto its belly, and that she’s not too cold do work extremely well.

We wonder if the accelerometer would pick up more motion if the watch was hung from a string inside of a small enclosure. This way it would swing back and forth with small movements. But perhaps that would make the whole thing too bulky?

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Fifa Looks At Electronic Augmentation

The [Fédération Internationale de Football Association] is joining the growing list of professional sports that is adopting technological means in an attempt to help the human referees. After a botched call in 2010 the organization called for a system that would work day or night, with 100% accuracy and the ability to report to the Refs in less than 1 second. The applicants have been weeded out and it comes down to two systems, both of which use a piece of personal hardware we’re quite familiar with. [Fe80], who sent in the tip, recognized the TI Chronos eZ430 watch in the image above.

The two systems both use the watch as an interface, but work very differently. The first, called GoalRef, uses a sensor suspended inside the ball. This detects a magnetic field made up by the goal posts. We’d guess it’s an inductance sensor that is triggered when it passes a coil in the goal posts (we didn’t find much in the way of technical info so please do your own speculation in the comments). The second system is very familiar. It’s the Hawkeye camera system used by the APT (Tennis) in all the major tournaments.

Ti Chronos Watch Controls Raspberry Pi

[Mike Field] was working on interfacing his TI Chronos eZ430 watch with the Raspberry Pi. As things were going pretty well, he took a side-trip from his intended hack and implemented watch-based control for an RPi audio player.

It really comes as no surprise that this is possible, and even easy. After all, the RPi board has native USB capability for hosting the watch‘s RF dongle, and it’s running Linux which we know already works well with the Chronos platform. But we still love the thought of having automation controls strapped to our wrist!

mpg321 is the audio playback program used for this hack. It plays MP3 files using ALSA for sound, which does have a few hiccups on the RPi. [Mike] found workarounds and included them in the C program he uses to gather everything into one nice code package. Control depends on keypresses sent from the watch (meant for use with PowerPoint) which are translated by his code and pushed to the audio/mp3 programs.

Hacking The Chronos And Exploring The ISM Bands

Take a few minutes and watch [atlas of d00m], at Shmoocon 2012, presenting information about using the RF dongle from the Chronos to explore ISM bands. Admittedly, I’m not very familiar with many of the things he discusses, but the words make sense. The bits and pieces I am familiar enough with to comprehend are truly fascinating. He covers typical methods of RF modulation as well as some hardware specific information to that dongle.

If you have a few minutes, or want more security related stuff, check out all the coverage from Shmoocon 2012. Tons of great videos here.

Continue reading “Hacking The Chronos And Exploring The ISM Bands”