I was nerd-sniped (reference from xkcd) by a colleague who wanted to do a cryptographic game for his kids, for a birthday party. The idea was to have a device to allow the kids to encrypt / decrypt a message Principle It's using the Caesar cipher, which is a simple shift cipher. It's super unsafe …
Category: Hacking
From a cheap crate to a treasure chest
For my kids birthday, my wife wanted to organize a treasure hunt. The idea was to have a bunch of indices, that would eventually leading to getting 4 numbers, used to unlock a paddlock holding chains around a chest. While the idea seems sound, devils in the detail as we wanted the cost to be …
Create a video lamp
I'm doing quite a lot of video conferences from home and I've decided to improve my setup, to have better quality, and ideally, at some point, be able to use it for some Youtube tutorials. I still somehow naively think I'll eventually find some time to do that... Anyway, as I've discovered recently and explained …
From better video to better still pictures
Earlier today, I was in a meeting and I was thinking how to improve the quality of my video conference that I often do from home. I was at the time especially focussed on how to improve the sound quality. After some Nerd Sniping from my boss, I ended up reading about some internal document that …
Building a microscope
I recently bought on aliexpress a powerful (and cheap) microscope. For 15 bucks however, the feature set is quite limited and it has no autofocus, meaning the body needs to be moved to put things in focus. As the official support has 2 ball joints, it's almost impossible to be accurate : when moving focus, …
g-watch crashlooping
I have a LG G-watch (android smart watch, the square one). I'm not using it much and it mostly seats on my desk, uncharged. For some reason, I decided to give it another try and it could never start: just after boot, it would say that settings crashed, proposing to wait or to close. Tried …
Box for GoPro batteries
I recently bought a GoPro and wanted to make a box to store the batteries. To be clear, my model is Hero 4 Silver and is using these (AHDBT-401) batteries. It's easy to find the electrical properties (3.8V DC, 1160mAh, 4.4Wh), not so easy to find the physical size. Here is a quick overview of the key …
Box with non vertical sides
While creating a perch for our parrot, I stumbled upon something non trivial : if you want to assemble a box with non vertical sides, what cut angle are you supposed to use to have a nice assembly ? It's obvious that it should be a trapeze, but what would be the α angle ? Easy …
Egg shape and camshaft
Introduction For some tinkering, I wanted to be able to draw a standard, egg-shaped cam and compute the displacement it was generating. I thought this was a trivial problem, but I couldn't find anything, so I'll describe the path I used. As a side note, the end-goal was to generate some 3D animation with persistence …
Screen/laptop holder
Until recently, main screen was resting on thick book to be slightly higher and end up in front of my eyes. As part of a revamp of my setup, I decided it was time for an upgrade. I had some specific needs: my screen needed to be roughly 10cm higher than desk I have a …
