Everything You Wanted To Know About SDRAM Timing But Were Afraid To Ask

One of the problems with being engaged in our hobby or profession is that people assume if you can build a computer out of chips, you must know all the details of their latest laptop computer. Most of the memory we deal with is pretty simple compared to DDR4 memory and if you’ve ever tried tweaking your memory, you know a good BIOS has dozens of settings for memory. [Actually Hardcore Overclocking] has a great description of a typical DDR4 datasheet and you can watch it in the video below.

Of course, he points out that knowing all this really doesn’t help you much with memory overclocking because you can’t really predict the complex effects without trial and error. However, most of us like to understand the knobs we are randomly twisting. On top of that, one theme of the video is that DRAM is dumb and simple. If you’ve ever thought about using it in a project, this might be a good place to start.

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E-paper Price Tags Combined To Create A Large Wireless Display

E-paper price tags have become popular for retail stores over the past few years, which is great for hackers since we now have some more cheap commodity hardware to play with. [Aaron Christophel] went all on creating grid displays with E-paper price tags, up to a 20×15 grid.

E-paper price tags are great for these kinds of projects, since they are wireless, lightweight, and can last a long time with the onboard batteries. To mount the individual tags on the plywood backboard,[Aaron] simply glued Velcro to the backboard of the tags. The displays’ firmware is based on the reverse engineering work of [Dmitry Grinberg], flashed to a few hundred tags using a convenient 3D printed pogo pin programming jig. All the displays are controlled via a Zigbee USB dongle plugged into a PC running station software.

[Aaron] is also experimenting with the displays removed from their enclosure and popped into a 3D printed grid frame. The disadvantage is the loss of the battery holders and the antenna, which are both integrated into the enclosure. He plans to get around this by powering the displays from a single large battery, and connecting an ESP32 to the displays via ISP or UART.

This project comes hot on the heels of another E-ink grid display project that uses Bluetooth and a rather clever update scheme.

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Lawnmower Doesn’t Need A Base Station

A recent tour of an old WWII-era aircraft carrier reminded us how hard navigation was before the advent of GPS. It used to be the work of skilled people to sight the sun or the stars and use giant books to figure out a vessel’s position. Now you just ask your phone to listen to some GPS satellites and you have precision undreamed of with other systems. But GPS sometimes isn’t enough. Just using conventional GPS, you can locate yourself to a couple of meters. The new L5 band, which isn’t on all satellites yet, can get you to about 30cm. But if you need better — up to around 1 or 2 cm — you need to use special techniques lumped together as GNSS enhancements. [Viktor] wanted to have an Arudino -based lawnmower, but wanted to use more conventional GPS techniques along with ultrawideband (UWB) ranging tags.

Given that the ranging anchors are in the mowing area, we aren’t sure why the mower even has GPS other than to geofence so you can’t start autonomous operations until you are in range of the tags. The three anchors are placed in a triangle, so if the robot knows the distance to each tag it can use some math to locate itself inside the area quite precisely.

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BPS.Space Succesfully Lands A Model Rocket

If you’ve been following [Joe Barnard]’s rocketry projects for the past few years, you’ll know that one of his primary goals has been to propulsively land a model rocket like SpaceX. Now, 7 years into the rollercoaster journey, he has finally achieved that goal with the latest version of his Scout rocket.

Rocket touching down
We have touchdown!

Many things need to come together to launch AND land a rocket on standard hobby-grade solid fuel rocket motors. A core component is stabilization of the rocket during the entire flight, which achieved using a thrust-vectoring control (TVC) mount for the rocket motors and a custom flight computer loaded with carefully tuned guidance software. Until recently, the TVC mounts were 3D printed, but [Joe] upgraded it to machined aluminum to eliminate as much flex and play as possible.

Since solid-fuel rockets can’t technically be throttled, [Joe] originally tried to time the ignition time of the descent motor in such a manner that it would burn out as the rocket touches down. The ignition time and exact thrust numbers simply weren’t repeatable enough, so in his 2020 landing attempts, he achieved some throttling effect by oscillating the TVC side to side, reducing the vertical thrust component. This eventually gave way to the final solution, a pair of ceramic pincers which block the thrust of the motors as required.

Another interesting component is the landing legs. Made from light carbon fiber rods, they are released by melting a rubber band with nichrome wire and fold into place under spring tension. They also had to be carefully refined to absorb as much impact as possible without bouncing, which killed a few previous landing attempts.

Scrolling back through [Joe]’s videos and seeing the progress in his engineering is absolutely inspiring, and we look forward to his future plans. These include a functional scale model of the belly-flopping starship, a mysterious “meat rocket”, and the big one, a space shot to exceed 100 km altitude.

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ESP32 Powers Covert Pentesting Device

Looking to expand their hardware design experience, [mentalburden] recently put together a low-cost handheld gadget that can be used for various security-related tasks such as logging WiFi traffic, operating as a dead drop, and performing deauthentication attacks.

The custom PCB plays host to the essentials — an ESP32-S microcontroller, AMS1117 3.3 V regulator, a SSD1306 OLED, and a couple of buttons. This lets the user navigate through a simple menu system and select whatever function they wish to enable. During testing, a pair of 18650 cells kept the electronics running for an impressive 22 hours.

A second version of the PCB fixed a few bodges that were required to get the original prototype working, and given how energy efficient the hardware ended up being,  [mentalburden] decided to drop the power supply down to a single 18650 for a total runtime of around 15 hours. A 3D printed case and some silicone buttons, produced with a simple clay mold, completed the package.

There’s still some improvements that could be made, namely integrating a battery charging circuit into the PCB and switching over to USB-C, but overall its a solid prototype with an impressive per-unit cost of less than $10 USD. Though if you’re looking for something even cheaper, we’ve seen an even more simplistic approach based on the ESP-01.

Books You Should Read: The Hardware Hacker’s Handbook

Here on Hackaday, we routinely cover wonderful informative writeups on different areas of hardware hacking, and we even have our own university with courses that delve into topics one by one. I’ve had my own fair share of materials I’ve learned theory and practical aspects from over the years I’ve been hacking – as it stands, for over thirteen years. When such materials weren’t available on any particular topic, I’d go through hundreds of forum pages trawling for details on a specific topic, or spend hours fighting with an intricacy that everyone else considered obvious.

Today, I’d like to highlight one of the most complete introductions to hardware hacking I’ve seen so far – from overall principles to technical details, spanning all levels of complexity, uniting theory and practice. This is The Hardware Hacking Handbook, by Jasper van Woudenberg and Colin O’Flynn. Across four hundred pages, you will find as complete of an introduction to subverting hardware as there is. None of the nuances are considered to be self-evident; instead, this book works to fill any gaps you might have, finding words to explain every relevant concept on levels from high to low.

Apart from the overall hardware hacking principles and examples, this book focuses on the areas of fault injection and power analysis – underappreciated areas of hardware security that you’d stand to learn, given that these two practices give you superpowers when it comes to taking control of hardware. It makes sense, since these areas are the focus of [Colin]’s and [Jasper]’s research, and they’re able to provide you something you wouldn’t learn elsewhere. You’d do well with a ChipWhisperer in hand if you wanted to repeat some of the things this book shows, but it’s not a requirement. For a start, the book’s theory of hardware hacking is something you would benefit from either way. Continue reading “Books You Should Read: The Hardware Hacker’s Handbook”

Hackaday Podcast 180: Tiny CRTs, Springy PCBs, And Measuring Trees

The demogorgon just wants to be friends. See? He’s waving hello.

This week, Editor-in-Chief Elliot Williams and Assignments Editor Kristina Panos traded sweat for silence, recording from their respective attic-level offices in the August heat unaided by fans (too noisy). We decided there’s no real news this week that lacks a political bent, except maybe that Winamp is back with a new version that’s four years in the making. (Is Winamp divisive?) Does it still whip the llama’s ass? You be the judge.

After Elliot gives Kristina a brief math lesson in increasing area with regard to 3D printer nozzle sizes, we talk a bit about 3D pens, drool over a truly customizable macropad that uses a microcontroller for each keyswitch, and  discuss dendrometers and tree health. Then it’s back to keyboards for one incredible modular build with an e-ink display and haptic feedback knob which is soon to go open source.

Finally, we talk tiny CRTs, a USB drive that must have the ultimate in security through obscurity, discuss the merits of retrograde clocks, and wonder aloud about the utility of jumping PCBs. Don’t bounce on us just yet — not until you hear about our first electronics wins and learn the one thing Kristina doesn’t do when she’s spending all day in the heat.

Direct download. And listen with Winamp!

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

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