Graupner R700 FM receiver – get the PPM signal

This must have already been discussed on plenty of other forums, but here I am, I want to use my Graupner FM transmitter / receiver with my quadcopter.

As Jordi from DIY Drones says “Intercept the PPM signal is the best way to obtain all the channels from any receiver, for a lot of reasons. The first one is performance, and the second is the simplicity (in code =P).“

First of all, here’s a quite useful diagram that explains well how the PPM works, and the relationship between this signal and the individual channels:

RC Receiver Timing Diagram

The Graupner/JR R700 FM receiver is quite easy to hack.

FEZ Domino – .NET Micro Framework

Arduino is great !

But programming in high level languages like Java all day long at work, I was started to grow increasingly frustrated with having to worry about “details” like memory management, no multi threading, string manipulation, etc. ..

So I was really looking for a micro controller / board that could be programmed with “real” java, powerful enough so that one doesn’t have to spend 80% of the time optimising the code, etc. …

I don’t remember how, but I found this FEZ Domino board (from TinyCLR) on the internet and I IMMEDIATELY knew it was for me…

Quite pricey compared with Arduino, but I’ve had it for a month now, and it’s such a pleasure to work with it… you still have to worry about some optimisation (for example I’m having 3 IR receivers on my Toy Tank and they all use interrupts and I realised that if I’m not careful the delay introduced by each, can affect the correct timings of the others !).

FEZ Domino with the "Component Shield" on it (I don't like the JST cable, I much prefer the RC servos ones)

Now I’m upgrading the Toy Tank to use this much more powerful board.