Robert Eisele
Engineer, Systems Architect and DBA

Operate a Syma S107G Remote Control Helicopter with an Arduino

Some time ago I saw people reverse engineering the infrared protocol of the Syma S107G toy helicopter and I wanted to get my hands on it as well. It is a coaxial helicopter, which means that it doesn't require a torque cancelling tail rotor. Yaw is controlled by using the speed difference to a second rotor underneath the main rotor, which spins in the opposite direction. It's really astonishing what good quality you get for just 20 bucks. It crashed quite often and it still flies like new.

How to map a Square to a Circle

When you work with a game controller, you would expect the joystick coordinates to be circular. In reality, you get the information from two seperated axis, which spans a rectangular coordinate-frame. I was thinking about how to derive a way of mapping a rectangular grid to a circular space like so (use your mouse):

Using Gamepads in JavaScript via node.js

I needed game controller support in node.js for a bigger JavaScript robotics project I'm currently working on. There are a few libraries already but none of them were sufficient for this job, so I wrote an own library called gamecontroller myself.

Set up Internet Sharing on Mac OSX using Command Line Tools

Even if Mac-OSX has a Unix core, Apple put some layers on top of it, which makes it rather hard to freely hack around. That's why I wrote an own small DHCP server recently. Configuring a Mac (Macbook Pro in my case) to act as a NAT router is hairy as well. Sure, there are the sharing options, but they're quite limited and bring their own DHCP server, with no control over it anymore.

A pure JavaScript DHCP implementation

When people connect to a WIFI to get internet access, they expect everything to work out of the box. This works because a new client on a network gets configured via the DHCP protocol. Most local routers have DHCP servers on it to deliver router-, DNS- and IP- information. What most people don't know is, how many options really can be configured with DHCP, as DHCP is expected to do just what is expected of it, without thinking about it anymore.

Using a Wii Nunchuk with Arduino

We've all grown up with gamepads in the hands, which makes them ideal to combine them with literally any possible application. A great invention of Nintendo is the Nunchuk, a cheap extension for the Wii U remote. As it uses I2C as transportation protocol, it's easy to access the raw data of the controller. As it is so easy, I thought there must be a standard solution for it, but couldn't find a stable implementation, but only loads of code snippets. That's why I focused on filling this gap and here it is. In this article, I'll guide you through the details and implement it for an Arduino.

Creating an Advent Calendar with HTML5 and CSS3

Christmas is near and I wanted to soothe the remaining time till Christmas Eve for my friends with something special. So I thought, why not building an Advent calendar with HTML5 and CSS3 for them, which gets filled with personal things I want to give to them? It turned out to be a very cool project and I wanted to share the thing in order to let you make one yourself for your own friends. If you just want to download the source, you can check it out on github, for everyone else, I'll guide you through the process of making an own Advent calendar.