[Mathieu] wrote in with his laser target practice game. It’s not the most amazing hack in the history of hackery, but it’s an excellent example of the type of simple and fun things you can do with just a little bit of microcontrollering.
First off, the gun is a broken toy gun that used to shoot something other than red collimated light beams. The Arduino knockoff inside reacts to a trigger pull and fires the laser for around 200 milliseconds. The gun also has a “gas gauge” that fills up with repeated shots and cools down over time. And therein lies the game — a simple race to ten, where each player only has a fixed number of shots over time.
The targets are simply a light sensor, scorekeeping LED display, and a buzzer that builds tension by beeping at you as the countdown timer ticks down. The bodies are made out of 3D-printed corners that connect some of [Mathieu]’s excess wooden goat-cheese lids.
All the code is up on GitHub so you can make your own with stuff that you’ve got lying around the house. The “gun” can be anything that you can embed a laser in that makes it aimable. Good clean fun!
[Sven337]’s rebuild of a cheap and terrible baby monitor isn’t super visual, but it has so much more going on than it first seems. It’s also a how-to for streaming audio via UDP over WiFi with a pair of ESP8266 units, and includes a frank sharing of things that went wrong in the process and how they were addressed. [Sven337] even experimented with a couple of different methods for real-time compression of the transmitted audio data, for no other reason than the sake of doing things as well as they can reasonably be done without adding parts or spending extra money.
The original baby monitor had audio and video but was utterly useless for a number of reasons (French). The range and quality were terrible, and the audio was full of static and interference that was just as loud as anything the microphone actually picked up from the room. The user is left with two choices: either have white noise constantly coming through the receiver, or be unable to hear your child because you turned the volume down to get rid of the constant static. Our favorite part is the VOX “feature”: if the baby is quiet, it turns off the receiver’s screen; it has no effect whatsoever on the audio! As icing on the cake, the analog 2.4GHz transmitter interferes with the household WiFi when it transmits – which is all the time, because it’s always-on.
Small wonder [Sven337] decided to go the DIY route. Instead of getting dumped in the trash, the unit got rebuilt almost from the ground-up.
Continue reading “Baby Monitor Rebuild is also ESP8266 Audio Streaming How-To”
Hackers can be a diverse bunch. My old hackerspace had folks ranging from NSA employees (ahem, independent security contractors) to space-probe pilots to anarchist vegan punks. And we all got along because we shared a common love for what we’re doing. One summer night we were out late in Adams Morgan and my vegan-punk friend reaches into the trash can and pulls out a discarded pepperoni Jumbo Slice.
“Wait a minute! Vegans don’t eat pepperoni pizza with cheese.” But my friend was a “freegan” — a vegan who, for ethical reasons, won’t buy meat or milk but who also won’t turn it down if it’s visibly going to waste. It’s actually quite a practical and principled moral proposal if you think about it: he’s not contributing to the use of animals that he opposes, but he gets to have a slice of pizza just the same. And fishing a slice of pizza, in a cardboard container, off the top of the trashcan isn’t as gross as you’d imagine, although it pays to be picky.
A Fracker is Born
That was the night that we realized we all had something deeper in common: we were all “frackers”. If you’ve been around hackers long enough, you’ll have noticed this tendency, but maybe you’ve never put a name to it. Tearing something apart, even if you might break it in the process, isn’t a problem if you fished it out of the e-waste stream to begin with. If you’re able to turn it into something, so much the better. It’s all upside. Need practice de-soldering tricky ICs? Looking for a cheap target to learn reverse engineering on? Off to the trashcan! No hack is too dirty, no method too barbaric. It’s already junk, and you’re a fracker.
Do you have a junk shelf where you keep old heatsinks in case you need to cut some up and use it? Have you used a heat gun more frequently for harvesting parts than for stripping paint? Do you know that certain satisfaction that you get from pulling some old tech out of the junk pile and either fixing it up again or, better yet, making it do something else? You might just be a fracker too.
Continue reading “Frackers: Inside the Mind of the Junk Hacker”
Over here at Hackaday, we love stuff made from other (unrelated) stuff. Maybe it’s the ingenuity behind the build or the recycling of parts… or it could be both. Either way, it’s cool and a side benefit of re-using parts from the junk drawer is that it keeps the project cost down, maybe enough that the project wouldn’t even be feasible without the re-use of parts.
That brings us to the topic of this post, a Delta-style 3D Printer made from recycled parts not typically seen in such a machine. It was built by DIYer [hesamh] and is almost unrecognizable visually. The usual extruded aluminum or precision shaft frame has been replaced with 5 pieces of MDF, finger-jointed together at the seams. Attached to the 3 vertical MDF frame pieces are rail and carriage assemblies scavenged from Epson dot matrix prints saved from the scrap yard. The best part is that these rail/carriage assemblies already had stepper motors and belts installed!
The end effector is also unique among delta-style printers. This one is made from aluminum plate and provides a mount for the extruder. There is no need for a bowden tube setup when the extruder is mounted on the end effector, although the increase in mass may reduce the printer’s top speed. That’s fine by us as we’d rather have a good-looking slow print than a fast ball of spaghetti. Another scavenged stepper motor is used for the extruder. The accompanying belt pulley acts as a direct drive feed gear.
The print bed is a re-purposed flatbed scanner. The guts were removed and a heating element was placed under the glass. The bed heater is controlled separately by way of a household thermostat. An Arduino Leonardo and 4 stepper drivers replace the normally used Mega/RAMPS/Pololu combo. Overall, this is a cool build that shows what is possible with a little thought and resourcefulness. The only part used in this build that was actually made for use in a 3D Printer is the hotend!
[BenN] was at his local hackerspace one day when a friend stopped by and offered him a used 5AH lead acid battery. As any good tinkerer would, he jumped on the opportunity and immediately started looking around for a project to use the battery in. One of [BenN’s] recent other projects involved 12volt landscaping lights, the same voltage as the battery he was just given. At this point it was clear that he had a good start to making a lantern. This lantern project also supports [BenN’s]
obsession with hobby of preparing for the zombie apocalypse.
A lantern needs an enclosure. Over on the hackerspace’s spare-parts rack was an old ATX power supply. All of the internal electrical components were removed to make room for the battery which fit inside nicely. The landscaping light just happened to be slightly larger than the power supply’s fan cut outs. Once the grill was removed from the metal power supply enclosure, the lamp fit in nicely and was secured using silicone glue which can tolerate any temperature the bulb can produce.
The feature that separates a lantern from a flashlight is the top-mounted carrying handle and this lantern will receive one made from the wiring removed from the ATX power supply. The electrical wiring is fairly straight forward. The battery is connected to the landscaping light by way of the original ATX on/off switch. The two terminals of the battery were also wired to the power supply’s AC input connector. This allows [BenN] to connect a DC battery charger to two of the three pins in order to charge the battery. Although this is a creative way to re-use the AC connector, it leaves quite a bit of potential to accidently plug in a 120v AC cord!
Hardware hackers and makers like us may not be well known for our excellent hygiene habits, but after [Dan]’s creation, no one can claim he doesn’t know how to use one! Either out of a total disdain for tooth care, or hopefully, after using one properly for many months, [Dan] decided to turn his electric toothbrush into an engraving tool!
At around $4 and meant for cleaning plaque off teeth, this tool isn’t the most powerful engraver on the block, but is capable of good work on softer material such as acrylic. Be sure to check out the heart that was made with this improvised tool that introduced us to [Dan]’s work.
This is really a clever use of your resources, and the article gives a nice account of how the toothbrush was modified with pictorial directions. Besides it’s use as an engraving tool, this might give someone other ideas for alternate toothbrush uses. For another neat alternate home-item use, why not check out how to repurpose an air freshener as a camera trigger?
[Roy] over at GeekDad had a dead laptop battery on his hands, and decided he would disassemble it to see what useful things he could do with the cells inside. He mentions in his article that even though your laptop might be convinced that its battery is toast, more often than not just one or two cells are damaged. This may not be news to all of our readers, but is worth pointing out to those who might not be aware.
With the bad cells separated from the good, [Roy] thought up a couple of different uses for his newly acquired batteries. His initial idea was to power an LED flashlight that was made to run on the 18650 cells he recovered from his laptop – not a stretch of the imagination, but definitely useful. The second use he came up with was to pair two of the cells together in order to simultaneously power an Arduino and some small Lego motors.
[Roy] lays out all of the standard caveats you would expect regarding the care and feeding of the lithium cells, and even suggests rebuilding the laptop battery as an option for the more skilled members of his audience.
Now we understand that dismantling and re-using old laptop cells is not necessarily groundbreaking, but it’s definitely something that’s worth a bit of discussion. [Roy] admits that his two ideas fall far short of the “18650 Things” his article title suggests, so how about adding a few of your own?
If you have stripped down some laptop batteries to salvage the cells, let us know what you did with them in the comments – we would be interested in hearing about it.