Screenshot of the OpenAsar config window, showing a few of the configuration options

OpenAsar Tweaks Discord’s Frontend, Improves Performance And Privacy

June 19, 2022 by Arya Voronova 14 Comments

Not all hacking happens on hardware — every now and then, we ought to hack our software-based tools, too. [Ducko] tells us about a partially open-source rewrite of Discord’s Electron-based frontend. Web apps can be hard to tinker with, which is why such projects are to be appreciated. Now, this isn’t a reverse-engineering of Discord’s API or an alternative client per se, but it does offer a hopeful perspective on what the Discord client ought to do for us.

First of all, the client loads noticeably faster, not unlike the famous GTA Online speedup (which was also a user-driven improvement), with channel and server switching made less laggy — and the Linux updater was de-cruft-ified as well. [Ducko] tells us how she got rid of the numerous NPM dependencies of the original code – it turned out that most of the dependencies could be easily replaced with Node.JS native APIs or Linux binaries like unzip. Apart from much-appreciated performance improvements, there are also options like telemetry bypass, and customization mechanisms for your own theming. You won’t get Discord on your Apple ][ just yet, but the native client will be a bit friendlier towards you.

While Discord is ultimately a proprietary platform, we do it see used in cool hacks every now and then, like this tea mug temperature-tracking coaster. Would you like to code your own Discord bot? We wrote a walk-through for that. Last but not least, if you like what we wrote and you happen to also use Discord, you should check out the Hackaday Discord server!

Kved: An Embeddable Key/Value Datastore

June 14, 2022 by Dave Rowntree 7 Comments

At some point when developing embedded applications, you’re going to want to store unique values in non-volatile memory, values that can’t be fixed at compilation time. Many microcontrollers have a small amount of EEPROM memory for this very purpose, but it’s usually rather limited if it’s provided at all. Even if you do have a bit of space on an EEPROM at your disposal, actually formatting your values into the memory and dealing with the pesky problem of wear leveling (necessary for parameters that need to change often) can be a bit of a hassle.

Lucky for us, [Marcelo Barros] decided to share his own implementation, Kved (key/value database) which uses the flash memory instead for such storage. Kved implements a dictionary type data structure, using numeric keys and values, supporting a few integer types. Using the library should be straightforward enough, as [Marcelo] says, all you need are a pair of spare flash sectors and the ability to port the flash the sector read, write, and erase functions. There are plenty of examples of such code available for practically any microcontroller out there, so that should be no barrier. For those who want to play with it right now, the repo currently has ports for the STM32L433RC and STM32F411CE, as well as a simulated version you can compile and run on your computer.

From an implementation perspective, the write algorithm uses a COW (Copy On Write) method. Changed values are invalidated by over-writing the storage location with all-zeros, and re-writing the changed value to a new location, cycling through the unused locations until the sector is full. Data-integrity mechanisms are implemented, preventing corruption of the data structure due to power fail situations, so incorrectly written values will be corrected on start-up and not affect the integrity of the configuration.

When looking around, we found a similar project, Embedis, over on hackaday.IO, as well as this article on the subject of embedded filesystems from a little while back.

Yes We Have Random Bananas

June 12, 2022 by Al Williams 36 Comments

If you ask a normal person to pick a random number, they’ll usually just blurt out a number. But if you ask a math-savvy person for a random number, you’ll probably get a lecture about how hard it is to pick a truly random number. But if you ask [Valerio Nappi], you might just get a banana.

His post, which is in two parts, details how what computers generate are actually pseudo-random numbers. You can easily make sure that every number has the same probability of selection as any other number. The problem is that you have to start with something — usually called a seed. For the purposes of playing games, for example, you can grab some source of entropy like how many microseconds since a hardware timer last rolled over, the number of input pulses you’ve received from a mouse lately, or how long you had to wait for the enter key to depress after asking the user to press it. But if you know that seed and the algorithm you can perfectly predict what number the computer will generate next so it isn’t truly random.

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A Sipeed Tang Nano 9k board on a Thinkpad keyboard, with an LCD panel attached to it

An Open Toolchain For Sipeed Tang Nano FPGAs

June 12, 2022 by Arya Voronova 9 Comments

[Sevan Janiyan] shares their research on putting an open FPGA toolchain together. Specifically, this is an open toolchain for the Sipeed Nano Tang FPGAs, which are relatively cheap offerings by Sipeed from China. The official toolchain is proprietary and requires you to apply for a license that’s to be renewed every year. There’s a limited educational version you can use more freely, but of course, that’s not necessarily sufficient for comfortable work.

This toolchain relies on the apicula project, an effort to reverse-engineer, reimplement and document the Gowin FPGA bitstream format, as well as the gowin integration for nextpnr (an open tool for FPGA place-and-route). With a combination of yosys, apicula, nextpnr and openFPGAloader, [Sevan] put together a set of commands you can use to build gateware for your Nano Tang FPGAs – without any proprietary limitations blocking your way. They show a basic blinkie demo, and also a demo that successfully operates a parallel LCD connected to the board.

The availability of open toolchains for FPGAs has always been somewhat of a sore point. Wondering about open FPGA toolchains? This Supercon 2019 talk by Tim [Mithro] Ansell will get you up to speed!

We thank [feinfinger (sneezing)] for sharing this with us!

Homebrew An OS From Scratch? Snowdrop Shows How It’s Done

June 11, 2022 by Donald Papp 21 Comments

Ever wondered what it would take to roll your own OS? [Sebastian]’s Snowdrop OS might just provide you with some insight into that process, and maybe even some inspiration.

[Sebastian] created Snowdrop completely from scratch, using only x86 assembly language. It’s more than just bare-bones, and boasts a number of useful utilities and programs including a BASIC interpreter and linker (for creating standalone BASIC executables.) That’s not even touching on the useful essentials, like multitasking and a GUI framework. There are even a number of resources specifically for making game development easier. Because as [Sebastian] puts it, what’s a operating system without games?

Interested in giving Snowdrop a try, or peek at the source code? The binaries and sources section has all you need, and the other headings at the top of the page will send you to the various related goodies. If you have a few minutes, we recommend you watch a walkthrough of the various elements and features of Snowdrop in this video tour (embedded after the page break.)

Snowdrop is an ambitious project, but we’re not surprised that [Sebastian] has made it work; we’ve seen his low-level software skills before, with his fantastic efforts around the classic stand-up arcade game, Knights of the Round.

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LTSpice Tips And A Long Tutorial

June 7, 2022 by Al Williams 7 Comments

We always enjoy videos from [FesZ], so when we saw his latest about tips and tricks for LTSpice, we decided to put the 20 minutes in to watch it. But we noticed in the text that he has an entire series of video tutorials about LTSpice and that this is actually episode 30. So there’s plenty to watch.

Like any tips and tricks video, you might know some of them and you may not care about some of them — for example, the first one talks about setting the colors which is a highly personal preference. But it is a good bet you’ll find something to like in the video.

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LED Heart Keeps Tabs On Your RuneScape Character

June 2, 2022 by Tom Nardi 8 Comments

The MMORPG RuneScape holds a special place in the hearts of those who played it in the early 2000s. Sure it might seem exceptionally quaint by modern standards, but at the time it was groundbreaking stuff. Plus you could play it for free, which certainly helped get people onboard. While there’s a more modern build available, many who played the game from the early days prefer to stick with what they know, and continue to run a version of the game that has now become known as Old School RuneScape.

[Austin Blake] is one of those early adopters, and the work he put into this LED health indicator should tell you all you need to know about how dedicated he is to the classic game. The 3D printed heart holds an incredible 312 NeoPixel LEDs, which are controlled by a 5 volt compatible Arduino Nano Every located on the back side. Both the color and “fill level” of the heart will change in real-time to correspond to the health of the player character.

Building the light itself was pretty straightforward, but getting the health value from the game was another story. As [Austin] explains in the video, his first attempt involved using Python and some image recognition routines to literally read the indicator off of the screen. The idea worked, and is frankly a fascinating hack worth keeping in mind on its own, but unfortunately it was too slow to provide the real-time feedback he was looking for.

Eventually he turned his attention to RuneLite, which is an open source client for Old School RuneScape. Thanks to its open source nature he could have hacked a routine to read the current health value and send it off to the Arduino, but thanks to a mature plug-in system, he didn’t have to.

The game’s API let him create a simple and reliable way of getting the data out of the game, similar to what we see in the flight simulator community for driving physical gauges and displays. RuneLite features a repository of community-developed plugins, and [Austin] says that he’d be happy to submit his for inclusion if others are interested in building similar indicators — a perfect match for this motion-sensing RuneScape axe.

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