[domiflichi] is human and fallible. So he can’t be blamed for occasionally forgetting the laundry in one of the machines and coming back to a less than stellar result. However, while fallible, he is not powerless.
What if his washer/dryer could email or text him about his laundry? It seemed simple enough. Add a vibration sensor to the side of the machine along with some brains. When the load is done it will bother him until he comes down to push the button or There Will Come Soft Rains.
He started off with an Arduino-and-ESP8226 combination and piezo sensors. The piezos had lots of shortcomings, so he switched to accelerometers and things worked much better. We really like the way he mounts them to the side of the washer dryer using the PCB’s mounting screws as angle brackets. The case is a standard project box with some snazzy orange acrylic on the front.
It took some fiddling, but these days [domiflichi]’s clothes are fresher, his cats fed, and his appliances more aware. Video of it in operation after the break.
Considering that you can occasionally buy an inkjet for less than the ink, he decided to take the plunge and see if he could print on a swatch of fabric with his inkjet. The technique requires a printer, some wax paper, scissors, and an iron.
By adhering the wax paper to the fabric properly, it’s possible to run it through the printer without tears. (We’ll let you pick the heteronym.) The final step is to let the ink sit for an hour before running the iron over it again. This seems to cure the ink and it can even survive a few washings.
Being able to make any pattern of cloth on demand seems like a useful thing to keep in the toolbox!
The core of the build is a 16 bit microcontroller a dsPIC33FJ128GP802 from Microchip. It’s a humble chip to be doing so much. It uses a UBlox NEO-6M positioning module for the location and a custom built QFH antenna built after calculations done with an online calculator for the GPS half. The audio half is based around a VLSI VS1003b decoder chip.
The whole build is done with protoboard. Where the built in traces didn’t suffice enamel and wire wrap wire were carefully routed and soldered in place. There’s a 48pin LQFP package chip soldered dead bug style that’s impressive to behold. You can see some good pictures in this small gallery below.
A bit ago I wrote an article called, “Death To The 3.5mm Audio Jack, Long Live Wireless.” A few readers were with me, a few were indifferent, many were vehemently against me, and there was a, not insubstantial, subset in a pure panic about the potential retirement of a beloved connector. Now I used a lot of opinionated language dispersed with subjectively evaluated facts to make a case that the connector is out. Not today maybe, but there is certainly a tomorrow not so far off where there are more wireless headsets at the electronics store than wired ones.
The bumper design is particularly interesting. The magic happens with two rings of conductive filament. the bottom one is stationary while the top one is a multi material print with a flexible filament. When the ball runs into the bumper the top filament flexes and the lower rings contact. Awesome. Who wants to copy this over to a joystick or bump sensor for a robot first? Send us a tip!
The whole document can be read as a primer on pinball design. [Tony] starts by describing the history of pinball from the French courts to the modern day. He then works up from the play styles, rules, and common elements to the rationale for his design. It’s fascinating.
Then his guide gets to the technical details. The whole machine was designed in OpenSCAD. It took over 8.5 km of eighty different filaments fed through 1200+ hours of 3D printing time (not including failed prints) to complete. The electronics were hand laid out in a notebook, based around custom boards, parts, and two Arduinos that handle all the solenoids, scoring, and actuators. The theme is based around a favorite bowling alley and other landmarks.
It’s a labor of love for sure, and an inspiring build. You can catch a video of it in operation after the break.
We got quite a few tips in about a paper from Vanderbilt about a cool scrap metal battery they’ve been playing with. They made some pretty bold claims and when we fed the numbers in they pretty much say they’ve got a battery you can make at home, that can hold half as much as a lead acid, can be made out of scraps in a cave (even if you’re not Tony Stark), charge super fast,and can cycle 5,000 times without appreciable capacity loss. Needless to say that’s super cool.
Of course, science research is as broken as ever and the paper was hidden behind a paywall. Through mysterious powers such as the library and bothering people we were able to get past this cunning defense and read the paper. Unfortunately the paper reads more like a brag track than a useful experimental guide on how to build the dang battery. It’s also possible that our copy was missing some pages. Anyway, we want to do science!
Anyway, here’s what we know. The battery is based on an ancient battery called the Baghdad Battery. The ancient battery supposedly used iron and copper with a mystery electrolyte. The scrap battery, however, is made from scrap iron and scrap brass. The iron makes sense, but why brass? Well, brass has copper in it, and you can still get at it chemically even if it’s alloyed.
To that end, the next step was to throw some oxygen atoms in with those pesky Fe and Cu ones. The goal is to get a redox reaction going. If you do it right you can achieve pseudocapacitance. To to this the researchers used “common household chemicals and voltages” to anodize the iron and copper inside the brass. The press photo have them holding a gallon of muratic acid, if that helps. We don’t know, but if they can jam a few oxygen atoms in there then so can we!
After that it’s all about sitting the electrodes in a bath of potassium hydroxide. We guess you can scrape the inside of an AA for that. Anyway, the paper’s light on process but the battery seems really cool. They’re not pursuing this research for commercialization, instead going the OSHW route. They hope to get to the point where anyone can just grind up a bunch of scrap steel and brass, maybe throw it in a birdcage, anodize it, and get a super long life battery for grid use for less than a lead acid. If any of you manage to build one of these drop us a tip!
Raspberry Pi’s are a little weird. They mostly get crammed into the slots microcontrollers used to live in. The nice part about microcontrollers is that they just turn on and start going. There’s no OS to boot. No file system to mount. Of course the downside to microcontrollers is often that there’s no OS to boot and file system to mount. Regardless, mostly you’ve got to spend a bit configuring a Raspbian install before a Raspberry Pi really starts to encroach on the microcontroller’s territory.
Pi Bakery abstracts all this. You can drag blocks, representing scripts, in the order you’d like them run. If you want to your Pi to boot up, connect to WiFi, and then start a VNC server it’s as easy a dragging the blocks in the right order and filling in the blanks. You can see an example of it in operation in the video after the break.