Displays We Love Hacking: SPI And I2C

December 21, 2023 by Arya Voronova 18 Comments

I’ve talked about HD44780 displays before – they’ve been a mainstay of microcontroller projects for literal decades. In the modern hobbyist world, there’s an elephant in the room – the sheer variety of I2C and SPI displays you can buy. They’re all so different, some are LCD and some are OLED, some have a touchscreen layer and some don’t, some come on breakouts and some are a bare panel. No matter which one you pick, there are things you deserve to know.

These displays are exceptionally microcontroller-friendly, they require hardly any GPIOs, or none extra if you already use I2C. They’re also unbelievably cheap, and so tiny that you can comfortably add one even if you’re hurting for space. Sure, they require more RAM and a more sophisticated software library than HD44780, but with modern microcontrollers, this is no problem at all. As a result, you will see them in almost every project under the sun.

What do you need for those? What are the requirements to operate one? What kind of tricks can you use with them? Let’s go through the main aspects.

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Hacker Tactic: Internal ESD Diode Probing

December 14, 2023 by Arya Voronova 15 Comments

Humans are walking high voltage generators, due to all the friction with our surroundings, wide variety of synthetic clothes, and the overall ever-present static charges. Our electronics are sensitive to electrostatic discharge (ESD), and often they’re sensitive in a way most infuriating – causing spurious errors and lockups. Is there a wacky error in your design that will repeat in the next batch, or did you just accidentally zap a GPIO? You wouldn’t know until you meticulously check the design, or maybe it’s possible for you to grab another board.

Thankfully, in modern-day Western climates and with modern tech, you are not likely to encounter ESD-caused problems, but they were way more prominent back in the day. For instance, older hackers will have stories of how FETs were more sensitive, and touching the gate pin mindlessly could kill the FET you’re working with. Now, we’ve fixed this problem, in large part because we have added ESD-protective diodes inside the active components most affected.

These diodes don’t just help against ESD – they’re a general safety measure for protecting IC and transistor pins, and they also might help avoid damaging IC pins if you mix. They also might lead to funny and unexpected results, like parts of your circuit powering when you don’t expect them to! However, there’s an awesome thing that not that many hackers know — they let you debug and repair your circuits in a way you might not have imagined.

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PCIe For Hackers: External PCIe And OCuLink

December 13, 2023 by Arya Voronova 23 Comments

We’ve seen a lot of PCIe hacks on Hackaday, and a fair few of them boil down to hackers pulling PCIe somewhere it wasn’t meant to be. Today, we routinely can find PCIe x1, x2 and x4 links sitting around in our tech, thanks to the proliferation of things like NVMe SSDs, and powerful cheap SoCs that make PCIe appear at your fingertips.

In the PCIe For Hackers series, we’ve talked about PCIe and how cool it is, all the benefits it has for hackers, gave you layout and interconnection rules, and even went into things like PCIe switches and bifurcation. However, there’s one topic we didn’t touch much upon, and that’s external PCIe links.

Today, I’d like to tell you about OCuLink – a standard that hackers might not yet know as an option whenever we need to pull PCIe outside of your project box, currently becoming all that more popular in eGPU space. Essentially, OCuLink is to PCIe is what eSATA is to SATA, and if you want to do an eGPU or an external “PCIe socket”, OCuLink could work wonders for you.

Respectable Capabilities

Just like any high-speed standard, PCIe has some tight requirements when things get fast. Even though PCIe is known to be not as sensitive to lower-quality links due to its link training and generation downgrade abilities, at higher link speeds, even through-hole vs SMD sockets can make a difference. So, if you want to go high-throughput, you want proper cabling and connectors, intended for out-of-chassis use – and OCuLink gives you all of this, at a low price.

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Check Your Board: Call For Submissions

December 8, 2023 by Arya Voronova 41 Comments

As both beginning hackers and Silicon Valley investors alike keep discovering, there are a lot of differences between hardware and software. One important difference is cost of iterating over a design. In software, you can comfortably rerun your build process and push updates out near instantly to tons of users. In hardware, all of that costs money, and I do mean, it costs way more money than you’d want to spend.

When I see people order boards that could never work because of some fundamental design assertions, with mistakes entirely preventable, it hurts. Not in an “embarrassment” way – it’s knowing that, if they asked someone to take a look at the design, they could’ve received crucial feedback, pulled the traces on the board differently or added some components, and avoided spending a significant chunk of money and time expecting and assembling a board that has a fundamental mishap.

Every thing like this might set a beginner back on their hacker journeys, or just have them spend some of their valuable time, and we can do a ton to prevent that by simply having someone experienced take a look.

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USB-C For Hackers: Program Your Own PSU

December 4, 2023 by Arya Voronova 20 Comments

Last time, I showed off a few ways you can convert an existing PSU to USB-C duty, and zoomed in on a particular way you can use to convert one of the ever-abundant 18 V – 20 V laptop PSUs to USB-C. All we have left is to write software for it, and I’ll explain how it works. There’s also that one cool USB-C secret I’ve found out, but you’ll have to read on to find out more.

From the last article, we have a board that has an RP2040 and FUSB302 combo on it, which takes a 20 V DC PSU input from a laptop brick, and can switch either 5 V, 20 V or 0 V to its USB-C socket using FETs. The USB-C communication firmware is simple enough, but there’s caveats, especially regarding safety. Let’s go through those!

The Code Logic

VBUS has to be non-powered by default – we only supply 5 V when the FUSB302 detects a 5.1 kΩ pulldown on one of the CC lines. After supplying 5 V, we send out PSU capability advertisements, of the kind that we’ve learned to parse in the Replying PD article – and whenever we get a Request, we have to switch to the requested profile, connecting the voltage rail requested to the FET. I opt to not do any current consumption control in this design, assuming a well-behaved device, but you theoretically should do that. It wouldn’t be hard to add a high-side current sensor, say, something from Analog Devices – I just don’t want to do that now, especially given that I’m already using two of the exposed ADC pins to do Lenovo/HP PSU capability detection instead, one is used up for VBUS measurement, and the fourth is used for VIN (20 V rail) measurement – that’s four ADCs, which is as much as the RP2040 has got. However, if I ever need more ADCs, I can add an analog mux like 4051 in the next version! Continue reading “USB-C For Hackers: Program Your Own PSU” →

Revive A Sony Vaio P-Series With KiCad’s Background Bitmaps

November 20, 2023 by Arya Voronova 31 Comments

You might remember that KiCad 7 came out this February, with a multitude of wonderful features. One of them was particularly exciting to see, and the KiCad newsletter even had an animated GIF to properly demo it – a feature called “Background Bitmaps”, which is the ability to add existing board images into your board editor, both front and back, and switch between them as you design the board. With it, you can draw traces, recreate the outline and place connectors over these images, giving you a way to quickly to reproduce everything on an existing PCB! I’ve seen some friends of mine use this feature, and recently, I’ve had a project come up that’s a perfect excuse for me to try it.

Back in 2020, I managed to get a Sony Vaio P from a flea market, for about 20€. It’s a beloved tiny laptop from 2009, now a collectors item, and we’ve covered a few hacks with it! The price was this wonderful only because it was not fit for regular flea market customers – it was in bad condition, with the original DC jack lost and replaced by some Molex-like power connector, no hard drive, and no battery in sight.

In short, something worth selling to a known tinkerer like me, but not particularly interesting otherwise. Nevertheless, about half a year later, when I fed it the desired 10.5 V from a lab PSU and gave the power button a few chances, it eventually booted up and shown me the BIOS menu on the screen! I’ve disassembled and reassembled it a few times, replaced the DC jack with an original one from a different Vaio ultrabook I happened to have parts from, and decided to try to bring it back to original condition.

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How Framework Laptop Broke The Hacker Ceiling

October 30, 2023 by Arya Voronova 25 Comments

We’ve been keeping an eye on the Framework laptop over the past two years – back in 2021, they announced a vision for a repairable and hacker-friendly laptop based on the x86 architecture. They’re not claiming to be either open-source or libre hardware, but despite that, they have very much delivered on repairability and fostered a hacker community around the laptop, while sticking to pretty ambitious standards for building upgradable hardware that lasts.

I’ve long had a passion for laptop hardware, and when Hackaday covered Framework announcing the motherboards-for-makers program, I submitted my application, then dove into the ecosystem and started poking at the hardware internals every now and then. A year has passed since then, and I’ve been using a Framework as a daily driver, reading the forums on the regular, hanging out in the Discord server, and even developed a few Framework accessories along the way. I’d like to talk about what I’ve seen unfold in this ecosystem, both from Framework and the hackers that joined their effort, because I feel like we have something to learn from it.

If you have a hacker mindset, you might be wondering – just how much is there to hack on? And, if you have a business mindset, you might be wondering – how much can a consumer-oriented tech company achieve by creating a hacker-friendly environment? Today, I’d like to give you some insights and show cool things I’ve seen happen as an involved observer, as well as highlight the path that Framework is embarking upon with its new Framework 16.

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