Sony Vaio Revived: How Does One Start?

A long-term project of mine is the the Sony Vaio new mainboard project. A year ago, I used it as an example to show you the cool new feature in KiCad 8, known as “background bitmaps”.

There are a heap of cool aspects to this specific Sony Vaio. It’s outrageously cute and purse-sized, the keyboard is nice enough for typing, motherboard schematics are available (very important!), and it’s not too terribly expensive. Of course, the most motivating aspect is that I happen to own one, its mainboard is not in the best state, and I’ve been itching to make it work.

It turned out to be a pretty complicated project, and, there was plenty to learn – way more than I expected in the beginning, too. I’m happy to announce that my v1 PCB design has been working wonders so far, and there are only a few small parts of it left untested.

I know that some of you might be looking to rebuild a lovely little computer of your choice. Hell, this particular laptop has had someone else rebuild it into a Pi-powered handheld years ago, as evidenced by this majestic “mess of wires” imgur build log! In honor of every hacker who has gotten their own almost-finished piece of hardware waiting for them half-assembled on the shelf, inside a KiCad file, or just inside your mind for now, let’s go through the tricks and decisions that helped make my board real.

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Apollo-era PCB Reverse Engineering To KiCad

Earlier this year [Skyhawkson] got ahold of an Apollo-era printed circuit board which he believes was used in a NASA test stand. He took high quality photos of both sides of the board and superimposed them atop each other. After digging into a few obsolete parts from the 1960s, he was able to trace out the connections. I ran across the project just after making schematics for the Supercon badge and petal matrix. Being on a roll, I decided to take [Skyhawkson]’s work as a starting point and create KiCad schematics. Hopefully we can figure out what this circuit board does along the way.

The board is pretty simple:

  • approximately 6.5 x 4.5 inches
  • 22 circuit edge connector 0.156 in pitch
  • 31 ea two-terminal parts ( resistors, diodes )
  • 3 ea trimmer potentiometers
  • 7 ea transistors
  • parts arranged in 4 columns

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Ubiquitous Successful Bus: Version 3

USB 2 is the USB we all know and love. But about ten years ago, USB got an upgrade: USB 3.0. And it’s a lot faster. It started off ten times the speed of USB 2, with 5 Gbps, and later got 20 Gbps and 40 Gbps revisions. How does that work, and how do you hack on it? Well, for a start, it’s very different from USB 2, and the hacking differs in many important ways.

In fact, USB 3 is an entirely separate interface from USB 2, and it does not depend on USB 2 in any way whatsoever – some people think that USB 3 negotiation happens through USB 2, but that’s a complete myth. USB 2 and USB 3 are electrically, physically, and logically distinct interfaces. Except for the fact that USB 3 is backwards compatible with USB 2, they are simply entirely different.

This also means that every USB-A port with USB 3 capabilities (typically blue, but not always) carries two interfaces; indeed, if you want, you can split a typical USB 3 port into a USB 3-only USB-A port and a USB 2-only USB-A port. USB 3-only ports are not legal per USB 3 standard, you’re expected to keep USB 2 there, but only for user convenience; you can split it with a hub and get, like, three extra USB 2 branches for your own use. Even if it’s forbidden, it works flawlessly – it’s what I’m currently using to connect my mouse to my laptop as I’m typing this!

Not to say that USB 3 is all easy to work with – there’s a fair bit of complexity.

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Switching Regulators: Mistake Fixing For Dummies

Some time ago, while designing the PCB for the Sony Vaio replacement motherboard, I went on a quest to find a perfect 5 V boost regulator. Requirements are simple – output 5 V at about 2A , with input ranging from 3 V to 5 V, and when the input is 5 V, go into “100% duty” (“pass-through”/”bypass”) mode where the output is directly powered from the input, saving me from any conversion inefficiencies for USB port power when a charger is connected. Plus, a single EN pin, no digital configuration, small footprint, no BGA, no unsolicited services or offers – what more could one ask for.

As usual, I go to an online shop, set the parameters: single channel, all topologies that say “boost” in the name, output range, sort by price, download datasheets one by one and see what kind of nice chips I can find. Eventually, I found the holy grail chip for me, the MIC2876, originally from Micrel, now made by Microchip.

MIC2876 is a 5 V regulator with the exact features I describe above – to a T! It also comes with cool features, like a PG “Power good” output, bidirectional load disconnect (voltage applied to output won’t leak into input), EMI reduction and efficiency modes, and it’s decently cheap. I put it on the Sony Vaio board among five other regulators, ordered the board, assembled it, powered it up, and applied a positive logic level onto the regulator’s EN pin.

Immediately, I saw the regulator producing 3 V output accompanied by loud buzzing noise – as opposed to producing 5 V output without any audible noise. Here’s how the regulator ended up failing, how exactly I screwed up the design, and how I’m creating a mod board to fix it – so that the boards I meticulously assembled, don’t go to waste.

Some Background… Noise

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Lithium-Ion Battery Hotswapping, Polarity, Holders

Everyone loves, and should respect, lithium-ion batteries. They pack a ton of power and can make our projects work better. I’ve gathered a number of tips and tricks about using them over the years, based on my own hacking and also lessons I’ve learned from others.

This installment includes a grab-bag of LiIon tricks that will help you supercharge your battery use, avoid some mistakes, and make your circuits even safer. Plus, I have a wonderful project that I just have to share.

Hot-swapping Cells

When your device runs out of juice, you might not always want to chain yourself to a wall charger. Wouldn’t it be cool if you could just hot-swap cells? Indeed it is, I’ve been doing it for years, it’s dead simple to support, but you can also do it wrong. Let me show you how to do it right!

Recently, a new handheld has hit the hacker markets – the Hackberry Pi. With a Blackberry keyboard and a colour screen, it’s a pretty standard entry into the trend of handheld Pi Zero-backed computers with Blackberry keyboards. It’s not open-source and the author does not plan to open-source its hardware, so I want to make it absolutely clear I don’t consider it hacker-friendly or worth promoting. It did publish schematics, though, and these helped me find a dangerous mistake that the first revision made when trying to implement LiIon battery hot-swap. Continue reading “Lithium-Ion Battery Hotswapping, Polarity, Holders”

Laser Cutters: Where’s The Point?

It is funny how when you first start doing something, you have so many misconceptions that you have to discard. When you look back on it, it always seems like you should have known better. That was the case when I first got a low-end laser cutter. When you want to cut or engrave something, it has to be in just the right spot. It is like hanging a picture. You can get really close, but if it is off just a little bit, people will notice.

The big commercial units I’ve been around all had cameras that were in a fixed position and were calibrated. So the software didn’t show you a representation of the bed. It showed you the bed. The real bed plus whatever was on it. Getting things lined up was simply a matter of dragging everything around until it looked right on the screen.

Today, some cheap laser cutters have cameras, and you can probably add one to those that don’t. But you still don’t need it. My Ourtur Laser Master 3 has nothing fancy, and while I didn’t always tackle it the best way, my current method works well enough. In addition, I recently got a chance to try an XTool S1. It isn’t that cheap, but it doesn’t have a camera. Interestingly, though, there are two different ways of laying things out that also work. However, you can still do it the old-fashioned way, too. Continue reading “Laser Cutters: Where’s The Point?”

I2C For Hackers: The Basics

You only really need two data wires to transfer a ton of data. Standards like UART, USB2, I2C, SPI, PS/2, CAN, RS232, SWD (an interface to program MCUs), RS485, DMX, and many others, all are a testament to that. In particular, I2C is such a powerful standard, it’s nigh omnipresent – if you were to somehow develop an allergy to I2C, you would die.

Chances are, whatever device you’re using right now, there’s multiple I2C buses actively involved in you reading this article. Your phone’s touchscreen is likely to use I2C, so is your laptop touchpad, most display standards use I2C, and power management chips are connected over I2C more often than not, so you’re covered even if you’re reading this on a Raspberry Pi! Basically everything “smart” has an I2C port, and if it doesn’t, you can likely imitate it with just two GPIOs.

If you’re building a cool board with a MCU, you should likely plan for having an I2C interface exposed. With it, you can add an LCD screen with a respectable resolution or a LED matrix, or a GPS module, a full-sized keyboard or a touchpad, a gesture sensor, or a 9 degree of freedom IMU – Inertial Measurement Unit, like a accelerometer+compass+gyroscope combination. A small I2C chip can help you get more GPIOs for your MCU or CPU, or a multi-channel motor driver, or a thermal camera, or a heap of flash memory; if you’re adding some sort of cool chip onto your board, it likely has an I2C interface to let you fine-tune its fancy bits.

As usual, you might have heard of I2C, and we sure keep talking about it on Hackaday! There’s a good few long-form articles about it too, both general summaries and cool tech highlights; this article is here to fill into some gaps and make implicit knowledge explicit, making sure you’re not missing out on everything that I2C offers and requires you to know!

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