Strings of LEDs are a staple of the type of project we see here at Hackaday, with addressable devices such as the WS2812 in particular having changed beyond recognition what is possible on a reasonable budget. They’ve appeared in all kinds of projects, but are perhaps most memorable when used in imaging projects such as screen-like arrays or persistence-of-vision systems. There’s another addressable LED product that we haven’t seen here, which is quite a surprise considering that it can be found with relative ease in junk piles and has been on the market for decades. We’re talking about the LED printer, and the addressable LED product in question is a very high density array of LEDs the width of a page, designed to place an image of the page to be printed on the toner transfer drum.
There’s a lot of mysticism around coffee roasting, but in the end it couldn’t be simpler. Take a bunch of beans, heat them up evenly, and stop before they get burned. The rest is details.
And the same goes for coffee roasters. The most primitive roasting technique involves stirring the beans in a pan or wok to keep them from scorching on the bottom. This works great, but it doesn’t scale. Industrial drum roasters heat a rotating drum with ridges on the inside like a cement mixer to keep the beans in constant motion while they pass over a gas fire. Fluidized-bed roasters use a strong stream of heated air to whirl the beans around while roasting them evenly. But the bottom line is that a coffee roaster needs to agitate the beans over a controllable heat source so that they roast as evenly as possible.
My DIY coffee roaster gave up the ghost a few days ago and I immediately ordered the essential replacement part, a hot air popcorn popper, to avert a true crisis: no coffee! While I was rebuilding, I thought I’d take some pictures and share what I know about the subject. So if you’re interested in roasting coffee, making a popcorn popper into a roaster, or even just taking an inside look at a thoroughly value-engineered kitchen machine, read on!
If you have a laser printer, you’ve got your Christmas presents sorted out. At least if your family likes jigsaw puzzles. The idea is very simple, laminate a photograph onto some laser-cuttable board, and then run the laser over the outline of the pieces. Bam! Instant puzzle.
The trick is generating the puzzle outline, and of course there’s an online application for that. It’s got options that let you customize the piece count and shapes, and then download the result as an SVG image.
Unfortunately, it’s closed-source and makes the pieces a little bit too uniform for our liking — many of the pieces have exactly the same shape as each other. Are you up to the challenge of writing a better one? We’d love to see it, because the idea of a simple puzzle overlay for laser cutters is too good. Help us get started with some brainstorming in the comments below. How do you go about generating meaningfully unique jigsaw edges algorithmically?
Once you’ve got the puzzle cut out, you can seal up the surface nicely, toss it in a box, and then you’ve got a personalized present. To put it together, we suggest an accompanying DIY pick-and-place tool. (And kudos to [Kristina] for the best headline of 2015 on that one!)
Thanks to Hackaday alum [George Graves] for the tip!
This experiment was started at Trinity College Dublin way back in 1944. Its purpose is to prove that tar flows, and indeed it does let go of a drop about every ten years. The thing is that nobody has ever seen that happen, bringing up the “if a tree falls in the forest” scenario. The Nature article on this event even mentions another experiment whose last drop was missed because the camera monitoring it was offline. This time around they did get some footage of the (un)momentous event which you can see below.
So here’s the challenge for clever hackers: What’s the easiest rig you can think of that won’t just continuously film the experiment but can also ensure that you get the goods on tape when a drop does fall? We see all kinds of high-speed shutter triggers — here’s one of the latest. But we don’t remember seeing an extremely slow version of the same. Let us know your idea by leaving a comment.
This is Sony’s smart watch, which has been around for a while now. It’s designed for use with your Android phone, and has always included an SDK that allows app developers to interact with it. But now Sony is taking it one big step further. They’ve published everything you need to know to hack your own firmware for the SmartWatch.
The navigation scheme for that articles includes five menu items at the bottom which you’ll want to dig through. The most interesting to us was the one labeled “SmartWatch hacker guide”. It lays bare the hardware used in the watch and how it’s peripheral component connect to each other. This starts with the STM32 (ARM) microcontroller that drives the watch. It goes on to document how the screen is addressed (SPI1) including the pin to turn it on and off. The same goes for the Bluetooth, accelerometer, buzzer, and touch sensors.
Firmware is updated via USB using Device Firmware Upgrade (DFU) mode. We don’t don’t see any way to connect an on-chip debugger. We searched to see if there is a JTAG port on the circuit board and it sounds like getting the watch apart without breaking it is pretty tough.
Now that you don’t need to stick to what Sony had planned for the device, what do you want to do with your strapless wristwatch?
Ever since we played with the original AR drone back at CES a few years ago, we’ve been keeping an eye on them. While we all agree there are better quadcopters out there, the price point for a ready-to-fly quadcopter of this size is really great with these.
When the fake video from FPS Russia of the weaponized drone made the rounds earlier this year, we were surprised at how people reacted. Anyone who has messed with quadcopters recognized it as fake right off the bat (not to mention the overly cliche fake russian character).
We won’t be adding a full fledged firearm to this. Mainly because it simply can’t lift the weight (There are ones that can, but we couldn’t justify the cost just for that). We do have some ideas though.
Lets go over the specs of the AR Drone 2.0 first.
Earlier this week, I showed you [Naim Busek’s] kickstarter for his turn signal helmet. In that article I explained that, while the helmet is a neat idea, I was really interested in what [Naim] had told me about his power consumption. To put it the shortest way, he has made his arduino sleep so efficiently, it can be waiting for input longer than the battery’s optimum shelf life.
After that article, [Naim] wrote in to give me the details on what he did to achieve such an efficient system. You can read his entire explanation, un altered here.