If someone lobs a grenade, it’s fair to expect that something unpleasant is going to happen. Tear gas grenades are often used by riot police to disperse an unruly crowd, and the military might use a smoke grenade as cover to advance on an armed position, or to mark a location in need of an airstrike. But some gas grenades are meant to help, not hurt, like this talking gas-sensing grenade that’s a 2015 Hackaday Prize entry.
Confined space entry is a particularly dangerous aspect of rescue work, especially in the mining industry. A cave in or other accident can trap not only people, but also dangerous gasses, endangering victims and rescuers alike. Plenty of fancy robots have been developed that can take gas sensors deep into confined spaces ahead of rescuers, but [Eric William] figured out a cheaper way to sniff the air before entering. An MQ2 combination CO, LPG and smoke sensor is interfaced to an Arduino Nano, and a 433MHz transmitter is attached to an output. A little code measures the data from the sensors and synthesizes human voice readings which are fed to the transmitter. The whole package is stuffed into a tough, easily deployed package – a Nerf dog toy! Lobbed into a confined space, the grenade begins squawking its readings out in spoken English, which can be received by any UHF handy-talkie in range. [Eric] reports in the after-break video that he’s received signals over a block away – good standoff distance for a potentially explosive situation.
Continue reading “Hackaday Prize Entry: Gas Grenade Helps Instead of Exploding”
[Ray] is in a bit of a pickle. All appeared well when he began selling an ESP8266-based product, but shortly thereafter some of them got hot and let the smoke out. Not to worry, he recommends ignoring the problem since once the faulty components have vaporized the device will be fine.
The symptom lies in the onboard red power indicator LED smoking. (Probably) nothing is wrong with the LED, because upon testing the batch he discovered its current limiting resistor is sometimes a little bit low to spec. Off by a hair of, oh, call it an even 1000x.
Yep, the 4700 ohm resistor is sometimes replaced with a 4.7 ohm. Right across the power rail. That poor little LED is trying to dissipate half a watt on a pinhead. Like a sparrow trying to slow a sledgehammer, it does not end well. Try not to be too critical, pick ‘n place machines have rough days now and then too and everyone knows those reels look practically the same!
The good news is that the LED and resistor begin a thermal race and whoever wins escapes in the breeze. Soon as the connection cuts the heat issue disappears and power draw drops back to normal. Everything is fine unless you needed that indicator light. Behold – there are not many repairs you can make with zero tools, zero effort, and only a few seconds of your time.
[Ray] also recommends measuring and desoldering the resistor or LED if you are one of the unlucky few, or, if worst comes to worst, he has of course offered to replace the product too. He did his best to buy from authentic vendors and apologizes to the few customers affected. As far as he knows no one else has had this problem yet so he wanted to share it with the community here on Hackaday as soon as possible. Keep an eye out.
If you have never seen
smoke ISO9001-certified electronics repair before, there is a short video of this particular disaster upgrade caught live on tape after the break.
Continue reading “Faulty ESP8266s Release Smoke, Then Keep Working?”
The greatest of Halloween costumes start with an idea, but they’ve also got to have strong execution to pull the whole thing off. This year [Johanna Jenkins] decided to put together a Fembot Halloween costume which is a wonderful example of this concept. Going as a Fembot from Austin Powers: International Man of Mystery sounds like a lot of fun right off the bat, but a bit of work at the sewing machine and access to a wig shop in Hollywood really brought it to the next level. But [Johanna] didn’t stop at that. The Fembots have machine guns in their bras. After they’ve torn through all of their ammo they’re left with smoking barrels as nipples, and that final touch even made it into the costume. In the video after the break you can see [Johanna] showing off the small battery operated fog system she piped into the costume bra.
Continue reading “Fembot costume includes smoking nipples”
Moscow is in a bit of a hot spot right now, dealing with a heat wave and enormous wildfires. The combination of smoke, ash, and heat was driving Andrew up a wall so he built a contraption to provide some relief. It has two chambers, the bottom houses ice water, the top is an air baffle. A small DC fan pumps air into the upper chamber where it encounters the water being sprayed in from the lower reservoir. What results is a heat exchange similar to other diy AC setups we’ve seen. But Andrew also notes that after running the device for a while the smell of smoke and ash is gone. Can this setup be seen as an effective way to trap airborne smoke particles?
[Joel] wanted to use his newly acquired welding skills to make something useful. With tasty flesh in mind he put together this meat smoker. What resulted is incredible, but the fact that he then gave it away as a gift is just amazing.
A curved joint between two pipes is known as a ‘fish mouth’. They can be a hassle, as with the pirate wheel project, but [Joel] used his noggin to make things easier. He first modeled two 55 gallon drums in CAD. The intersecting curve was then generated by the software, printed out on paper, and stenciled on the drum to be cut out with a jigsaw.
[Joel’s] writeup is greatly detailed and shares many pictures. He makes every part of this smoker, including the wood handles and the stainless steel grates. The guy really knows how to build stuff, but we should have known that after seeing the Crushtoberfest.