Displays We Love Hacking: Parallel RGB

January 25, 2024 by Arya Voronova 8 Comments

You might have seen old display panels, from 3″ to 10″, with 40-pin FFC connectors where every pin seems to be used for some data signal. We call these displays parallel RGB, or TTL RGB, or DPI, and you can find them in higher-power MCU, Raspberry Pi, and other Linux SBC projects. You deserve to know what to do with those – let’s take a look.

The idea is simple – this interface requires you to constantly send a stream of pixels to the display, and you need to send those pixels through a parallel bus. You can send up to 8 bits per color channel per pixel, which makes for 24 bits, and the 24-bit mode is indeed the standard, but in practice, many parallel RGB implementations don’t bother with more than 5-6 bits of color – two common kinds of parallel RGB links are RGB565 and RGB666. The parallel RGB interface is a very straightforward approach to sending pixels to your display, and in many cases, you can also convert parallel RGB to LVDS or VGA interfaces relatively easily!

If you’re new to it, the easiest way you can drive a parallel RGB display is from a Raspberry Pi, where the parallel RGB interface is known as DPI. This is how 800 x 480 display Pi HATs like the Pimoroni HyperPixel work – they use up almost all of the GPIOs on your Pi, but you get a reasonably high-resolution display with a low power footprint, and you don’t need any intermediate ICs either. FPGAs and some higher-grade MCUs also often have parallel RGB output capability, and surely, someone could even use the RP2040 PIO as well!

Throughout the last decade, parallel RGB has been used less and less, but you will still encounter it – maybe you’re working with an old game console like the PSP and would like to put new guts into it, maybe you’re playing with some tasty display that uses parallel RGB, or maybe you’d like to convert parallel RGB into something else while treating it with respect! Let’s go through what makes parallel RGB tick, what tools you have got to work with it, and a few tips and tricks. Continue reading “Displays We Love Hacking: Parallel RGB” →

Ask Hackaday: What About Imperfect Features?

January 24, 2024 by Arya Voronova 24 Comments

Throughout the last few years’ time, I’ve been seeing sparks of an eternal discussion here and there. It’s a nuanced one, but if I could summarize, it’s about different feature development strategies we can follow to design things, especially if they’re aimed at a larger market. Specifically – when adding a feature, how complete and perfect should it be?

A while back, I read a Mastodon thread about VLC not implementing backwards per-frame skipping. At the surface level, it’s about an indignant user asking – what’s the deal with VLC not having a “go back a frame” button? A ton of video players have this feature implemented. There’s a forum thread linked, and, reading it could leave you with a good few conflicting emotions. Here’s a recap.

In what appears to be one of multiple threads asking about a ‘previous frame’ button in VLC, there’s an 82-post discussion involving multiple different VLC developers. The users’ argument is that it appears to be clearly technically possible to add a ‘previous frame’ button in practice, and the developers’ argument is that it’s technologically complex to implement in some cases – for certain formats, even impossible to implement! Let’s go into the developers’ stated reasoning in more details, then – here’s what you can find in the thread, to the best of my ability.

Continue reading “Ask Hackaday: What About Imperfect Features?” →

Switching Regulators For Dummies

January 22, 2024 by Arya Voronova 30 Comments

We often use linear regulators in our designs. They are cheap and simple – you put the regulator chip itself on the board, add two capacitors, and get a voltage. Linear regulators are imperfect, of course – they can’t help but waste the voltage difference as heat, for a start, which straight up excludes them for high-current purposes, or significant voltage difference conversions, unless you have a hefty heatsink handy. They also can’t boost voltage, which means you can only go from high to low – a bit of a disappointment.

Of course, we haven’t been just throwing our hands up in the air if a linear regulator doesn’t fit our purpose. Switching regulators have none of these disadvantages, which is why your mobile phone alone has a few dozen of these. They are way more efficient and hi-tec, able to convert one voltage into another while losing hardly any power into heat. All that you need to do is switch an inductor at a somewhat high frequency!

However, for some, switching regulators might look a bit intimidating. They tend to have higher standards for board layout compared to linear regulators, and, they do need an inductor – sometimes, a few more components too. Inductors alone are somewhat intimidating components, with a fair few more parameters than we’d expect, and you might get confused when looking into adding a switching regulator to your circuit.

No more! In this article, I shall give you the switching regulator basics, remove any fog of war that might be clouding your vision, and show you just how easily you can get a good few amps at your favourite voltage whenever you need it. Continue reading “Switching Regulators For Dummies” →

Two pictures of the mobo side by side, both with kapton tape covering everything other than the flash chip. On the left, the flash chip is populated, whereas on the right it's not

Enabling Intel AMT For BIOS-over-WiFi

January 5, 2024 by Arya Voronova 28 Comments

Intel ME, AMT, SMT, V-Pro… All of these acronyms are kind of intimidating, all we know about them is that they are tied to remote control technologies rooted deep in Intel CPUs, way deeper than even operating systems go. Sometimes though, you want remote control for your own purposes, and that’s what [ABy] achieved. He’s got a HP ProDesk 600 G3 Mini, decided to put it into a hard to reach spot in his flat, somewhere you couldn’t easily fetch a monitor and a keyboard for any debugging needs. So, he started looking into some sort of remote access option in case he’d need to access the BIOS remotely, and went as far as it took to make it work. (Google Translate)

The features he needed are covered by Intel AMT — specifically, BIOS access over a WiFi connection. However, his mini PC only had SMT enabled from the factory, the cut-down version of AMT without features like wireless support. He figured out that BIOS dumping was the way, promptly did just that, found a suitable set of tools for his ME region version, and enabled AMT using Intel’s FIT (Flash Image Tool) software.

Now, dumping the image could be done from a running system fully through software, but apparently, flashing back requires an external programmer. He went with the classic CH341, did the 3.3 V voltmod that’s required to make it safe for flash chip use, and proceeded to spend a good amount of time making it work. Something about the process was screwy, likely the proprietary CH341 software. Comments under the article highlight that you should use flashrom for these tasks, and indeed, you should.

This article goes into a ton of detail when it comes to working with Intel BIOS images — whichever kind of setting you want to change, be it AMT support or some entirely different but just as tasty setting, you will be well served by this write-up. Comments do point out that you might want to upgrade the Intel ME version while at it, and for what it’s worth, you can look into disabling it too; we’ve shown you a multitude of reasons why you should, and a good few ways you could.

Diagram from the blog post, showing how GATT communication capture works

Hacking BLE To Liberate Your Exercise Equipment

January 4, 2024 by Arya Voronova 17 Comments

It’s a story we’ve heard many times before: if you want to get your data from the Domyos EL500 elliptical trainer, you need to use a proprietary smartphone application that talks to the device over Bluetooth Low-Energy (BLE). To add insult to injury, the only way to the software will export your workout information is by producing a JPG image of a graph. This just won’t do, so [Juan Carlos Jiménez] gives us yet another extensive write-up, which provides an excellent introduction to practical BLE hacking.

He walks us through BLE GATT (Generic Attribute Profile), the most common way such devices work, different stages of the connection process, and the tools you can use for sniffing an active connection. Then [Juan] shows us a few captured messages, how to figure out packet types, and moves into the tastiest part — using an ESP32 to man-in-the-middle (MITM) the connection.

Continue reading “Hacking BLE To Liberate Your Exercise Equipment” →

The Pi Pico replacement board in question, assembled, held diagonally in some type of holder

ProPico For Your Pro Pico Needs

January 3, 2024 by Arya Voronova 6 Comments

Ever feel like the Pi Pico board could be doing way more given its footprint? Does it bother you that the RP2040’s ADC quality is even further decreased because of the noisy onboard switching regulator? Miffed about decisions like the MicroUSB socket, the 2MB flash, or lack of the reset button? [Dmytro] brings us an open-source Pi Pico design, sporting the same RP2040 and a fully compatible footprint, but adding a number of improvements to its surroundings.

There’s a good few additions, all of them hacker-friendly – [Dmytro] adds comfortably-spaced reset and boot buttons, a USB-C socket, a dedicated low-noise voltage reference for the ADC, one more LED, and an I2C EEPROM footprint socket that is compatible with FRAM chips. Everything worth preserving is preserved – the pinout stays the same, including the SWD connector, which now sports an extra RESET pin. The bottom side USB testpoints remain, with only the four testpoints changed for more useful signals. Last but not least, the switching regulator is replaced by the venerable 1117 – you lose the ability to power your Pico from two AAs, and the capacitor series resistor requirement isn’t great, but you can easily put one of the drop-in 1117 replacement regulators on there.

What’s great is that the design is fully open-source, with KiCad files available. Want to design your own Pi Pico footprint board, improve upon this one even further, or maybe make a more tailored one? Treat yourself to the GitHub repository! There’s also a pinout diagram and a KiCanvas schematic for all your tinkering needs. We’ve covered drop-in replacements for classic drawer-inhabiting parts like the Pi Zero, for the 7805 (twice!), the 6502 CPU, and even for the DE9 serial port connector. No matter the purpose, they’re always a joy to see.

The controller after the rebuild, looking just like the stock controller but with an external antenna attached

An Extensive Walkthrough On Building Your Own KSP Controller

January 3, 2024 by Arya Voronova 10 Comments

Having a game-tailored controller is a level-up in more ways than one, letting you perform in-game actions quickly and intuitively, instead of trying to map your actions to a clunky combination of keyboard and mouse movements. [abzman] took the Pelco KBD300A, a DVR-intended camera controller panel with a joystick, reverse-engineered it, and then rebuilt it into a Kerbal Space Program controller. What’s more, he documented every detail along the way!

The write-up is so extensive, it’s four separate posts — all of them worth reading without a doubt. In the first post, he describes the original hardware, the process of reverse-engineering it, and a few tips for your own RE journeys. Next, he covers about making his own board, showing all the small decisions he’s had to make, with plenty of KiCad screenshots. If you are on the lookout for designing such a board, there’s plenty to learn!

The original hardware didn’t go down without a fight — the third post talks about taming the seven-segment displays, the onboard joystick, and fighting with the key matrix wired in exactly the way you wouldn’t want. In the end, he shows us how you could tie a controller easily into Kerbal Space Program.

One more piece of hardware liberated, one more win for the hacker world. Whether it’s a Macintosh SE, a classic ThinkPad, or even a generic rotary tool, these upgrades are always a joy to see. If you wanted to learn to do such an upgrade yourself, here’s us showing how you can pull this off with a classic Sony Vaio!