Spektrum DX3S Hack (Part 2 - Telemetry and the first RX)

Back to the DX3S hack project, I got some time and took a look at the telemetry data. I didn't do any video, but the information below should be enough.

The telemetry data is fairly simple. On each 8 byte packet sent by the remote, the RF module responds with 8 bytes. Out of this 8 bytes, only bytes 3 and 4 are relevant.

Raspberry Pi (removing hub and adding a Li-Ion battery)

I had some problems regarding USB on the RPi + lapdock. I bought myself a Tp-Link TL-WN723N wireless (b/g/n) USB adapter to use it with my new "laptop". The problem was that it would not work with the lapdock connected at the same time. If I connected only the wireless dongle, it worked fine. Also, if I connected only the lapdock, it worked OK. When both of them were connected at the same time I got freezes and lots of kernel errors.

Raspberry Pi (modding Atrix Lapdock) - update 17 April 2013

I ordered a Motorola Atrix Lapdock to connect it to my Raspberry Pi. It's fairly cheap thinking about what you get (11.6" 1366x768 screen, USB hub, keyboard, touchpad, battery, charger and a case that hosts all of them).

So, the lapdock has a micro HDMI male connector (type D) and a micro USB male connector. The raspberry has a type A HDMI female connector and a female micro USB connector. I tought of adding a male type A HDMI connector to the lapdock so that I could connect the RPi directly to the lapdock.

Raspberry Pi

What is Raspberry Pi?
I don't think I can say it better than the official FAQ:

"The Raspberry Pi is a credit-card sized computer that plugs into your TV and a keyboard. It’s a capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. We want to see it being used by kids all over the world to learn programming."

ARM Music Player

And I finally finished it.


Here is a video showing the functionality. I removed the sound but you can make an idea.

And the source code Download.

Leave your impressions below.

ARM Music Player

As I said, I started working on an ARM music player based on the EMX module from GHI Electronics.

Here is a short video showing where I am with the project. I will release the source code soon.

Please leave your comments below.

Changing platform and results

I was getting a little tired of the little 8 bit microcontrollers and all their limitations so I started searching for a new (powerful) platform. So, what to search for? Because I've worked in the past only with Atmel chips (with some few exceptions) I started looking on the Atmel site on the AVR32 and ARM solutions. After a little discussion with some other people, I decided to start working with ARM chips so I began searching for developing tools (debuggers, programmers, compilers) to see if this would be cost effective. 

In my search I stumbled upon some great arm developing platforms from GHI Electronics that support .NET micro framework. I worked a little with .NET micro framework in the past (a very small project at school) and it seemed pretty great. Well, this modules are light years from great. You can event run unmanaged native code via RLP if you need real time capabilities and everything else you need is there, in the SDK. You can just start working on what you want to do.