Posts

Featured Post

Dynamic RAM from First Principles

Image
Before the past year, many of us took computer memory for granted. It was one of the lower-cost parts of a PC build and was usually available in whatever quantity one desired. As its cost has skyrocketed, a lot of PC builders and other users of computers in general are taking a deeper look at memory, how much is really needed, and what its functions truly are. [Igor] is working on a drum sequencer project which needs a small amount of memory, and has built this dynamic RAM from discrete components. The first video goes into the construction of the memory array and how its addressed. It’s only eight bytes total, and using fairly large electrolytic capacitors to store data means that a gigabyte of this memory would take up well over a thousand acres, but it’s still enough memory for [Igor]’s needs. In addition to the capacitor, each bit uses a pair of diodes to determine if a read or write is occuring, and a set of transistors on the read and write busses to perform th...

LightComposer – Reach Out and Touch Your Lighting

Image
While there is a time and place for wirelessly controlled devices, sometimes you want something you can just reach out and touch to interact with, no apps to install or devices to configure. In this case [John] wanted a lamp that was just that. Drawing inspiration from the rotary phone, he created the LightComposer . This small lamp, just a bit smaller than a hockey puck, uses a 3D printed enclosure and a straightforward PCB. It’s a very accessible project to recreate. The 3D prints are well thought out including a TPU ring on the bottom to keep the lamp from sliding around. The light source comes from 32 SK6812 LEDs, which are very similar to NeoPixels. An ATmega328P microcontroller powers the project and can easily be programmed using the Arduino IDE. A rotary encoder in the center, coupled to the top diffuser, lets you control LED brightness and color by turning it. The firmware also includes some fun hidden light-effect modes. Head over to [John]’s site for all the files needed ...

Investigating Annealing as Fix for Poor CF Adhesion in 3D Prints

Image
After recently publishing a few videos covering research into the poor adhesion between chopped carbon fiber (CCF) and the thermoplastic filaments as used with FDM 3D printing, some of the feedback received by [I built a thing] included the idea that the missing step to make CCF additives work was post-print annealing. Naturally this claim had to be investigated , both through the resulting physical characteristics as well as on a microscopic level in the same scanning electron microscope (SEM) as before. Post-annealing SEM scan, showing clear voids. (Credit: I built a thing, Youtube) Theories as to why annealing the parts would help here seem to focus on increased bonding and filling of voids in the printed CCF-infused material, while there are the typical worries with annealing such as parts warping and shrinking to also take into account as potential downsides of this treatment. For the sample materials PETG and PETG-CF, as well as PLA and PLA-CF filaments are used, with each fil...

Breaking Into a Prison Tablet

Image
Usually the term ‘jailbreaking’ isn’t meant to be taken quite that literally, but in the case of the US prison tablet that [Hugh Jeffreys] got sent, it’s really quite apt. Unlike the typical transparent prison electronics, this tablet is hermetically sealed inside an opaque plastic case, with the Windows 10 install firmly locked-down and not allowing anything more to be done with it than access some prison-provided services via the browser in kiosk mode. The first challenge was to see whether it could be booted at all, with just four metal pads visible on the side of the case. These turn out to correspond to USB pins, but the tablet only briefly tries to turn on with a charger connected. This means that a teardown is required, which ended up involving a hacksaw due to the sealed case. Inside the case is the Windows tablet with the back cover removed, presumably for easy access to extend its USB port. All of this is embedded in foam and more gunk that makes dis...

Won’t Somebody Please Think Of Banning The British Children!

Image
The British government is in a headlong rush to ban under-16s from social media, and restrict the access of under-18s. And in typical form, the EFF is here with a warning about the dangers and futility of such legislation . Kids aren’t stupid. They’ll use a fake ID like this one from the satirical https://use-their-id.com/ . Or they’ll become VPN experts. The proposed new law will involve an age restriction policed through online ID verification, something which will not be limited to the young, as every British adult will also have to show ID to access large parts of the Internet. There is little in the way of information about how this unprecedented invasion of privacy will be implemented, however we expect that it will be left to the lax security measures of a range of lowest-bidder third party identity verification services. The resulting database will become a very rich target indeed. The EFF pull no punches in warning of the harms these measures will bring u...

Brewing Espresso with Ultrasonic Assistance

Image
There are as almost as many kinds of coffee as there are of coffee drinkers, with each method for preparing the beverage appealing to a different kind of palate: moka pots, filter coffee, pour-over coffee, French presses, cold brews, espresso, and more produce their own unique flavours by extracting different compounds from the grounds to different degrees. Now, a new method has joined the throng: ultrasonic-assisted extraction, which can produce even an espresso at room temperature. Espresso is normally made by forcing hot water through tightly-packed, finely-ground coffee beans, quickly producing a concentrated extraction. Its one of the hardest kinds of coffee to consistently make well, since the outcome is influenced by everything from grind size and packing density to temperature, pressure, and more. Ultrasonic agitation helps here by creating cavitation bubbles, which form shock waves as they collapse, breaking open the bean structure and producing small, strong jets of water....

Hackaday Links: June 21, 2026

Image
Today marks the summer solstice, the longest day of the year and the start of astronomical summer in the Northern Hemisphere. This doesn’t really have much to do with hacking hardware or building gadgets other than the fact that from this point on you’ll have progressively less daylight hours to do it in each day. Of course, if you do your best work in the middle of the night this won’t impact things much. If you’re as likely to find a controller in your hand as a soldering iron in the evenings, you might be interested in a recent filing against Sony . Lawyers representing a group of four gamers allege that the entertainment giant is violating a California law that says digital storefronts need to make it clear that buyers don’t technically own the games in question but are merely licensing them — a license which, as we’ve seen in the past, can be revoked or modified at any time with no restitution made to the purchaser. Now while we agree con...