Author Archives: Matthew

Splines in Onshape, part 2

In this second part of the series, I’ll briefly cover drawing splines directly in 3D, and then discuss offset curves, which are the original reason I started on this long journey delving into Onshape curves. Continue reading

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Splines in Onshape, part 1

In this post I talk about splines and various ways they can be represented, with particular reference to Onshape, a web-based CAD system. Continue reading

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Dell Venue 11 Pro travel keyboard troubleshooting

Introduction I recently purchased a pair of Dell Venue 11 Pro 7140 tablet computers — one for myself and one for my girlfriend. I figured this would be a good crossover device between a tablet and a laptop, and so … Continue reading

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Unlocking my Lenovo laptop, part 3

The decryption function If you are just joining this story you may want to start at part 1. In part 2, we discovered that a embedded controller update is performed by uploading a small ‘flasher’ program to the EC. This … Continue reading

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Unlocking my Lenovo laptop, part 2

The embedded controller In part 1, we looked at the communication between a Lenovo Thinkpad X230T laptop and battery, and discovered that there a challenge-response protocol used to authenticate ‘genuine’ Lenovo batteries. On the laptop side, this – and battery … Continue reading

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Unlocking my Lenovo laptop, part 1

Introduction Two months ago, I bought a new battery for my Lenovo laptop (a ThinkPad X230T). I was about to go away on holidays and wanted a battery that could last me through a plane flight; the original battery was … Continue reading

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Introduction to photography slides

These are some slide decks I used to use when I ran introductory courses for the UNSW Photography Club. They are a pretty good set of slides so I figured they should have a home on the Web. Part I: … Continue reading

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Global food security

I went to a great lecture today by Professor Chris Barrett on “The Global Food Security Challenge in the Coming Decades”. The slides from this lecture are available here. Here are my notes: Current global food demand growth is ~1.25% … Continue reading

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Weather balloon physics

One of the simplest solutions for sending measurement instruments up into the stratosphere is a rubber balloon filled with hydrogen or helium. While the physics of such a balloon would seem to be simple, there are actually some interesting considerations.

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New site

Welcome to the newly redesigned zmatt.net. I seem to only get around to upgrading my personal website once every decade so this is a special day indeed. The biggest change is that I now have a blog here (powered by … Continue reading

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