Received my Arduino package on Tuesday (Sept 7th, 2010) from RobotShop.ca!
The WaveShield:
after a few issues (including Swear words & burn & wrong soldering & Soldering Iron issue) and 2 days, I managed to get the WaveShield all solder up and working. It’s not the best shield I could have got but it’s a cheap and cheerful solution for the Mouse Droid audio system. If I have to give comments on it, I’d say it’s an efficient solution if willing to sacrifice on sound quality (still better than some other solution) since the limit for the waves files are 16bits @ 22khz in Mono. As you can read, that’s a bit far from CD quality and galaxy-far from 328kbps MP3s but for replicating a droid which limit itself to ‘beep’ and ‘bloop’ and stuff like that, that’s Plenty. On the other hand, I would not use that shield when I’ll be building the Astromech since the R-Series have a bit more of an evolved sound system needs compared to the mouse droid. Another positive thingy about that shield is that it use SD cards and I had a few extra laying home so… quite a good thing for me.
R/C receiver:
I had this weird idea of using the Arduino to ‘listen’ on my Rx’s channels. At first, it was for fun that I tried but after a few trial/error, I got somewhat dedicated in making this work the way I would like it to so, I spent countless minutes/hours trying to figure out how to interpret the signal/pulse from the receiver with the Arduino. I came up with tons of idea, each weirder than the other but nothing was working. Deception was great BUT… out of a last attempt before giving up (read: to continue later), I tried to hook up the receiver power directly to the Arduino 5V / Gnd (since my batteries were dieing a bit). Out of nowhere, I looked at the serial output and I noticed that everything was working perfectly and my signal was always contained in between 1100 and 1900 microseconds depending on the High/Low of the Tx. Personal Hint: Never underestimate the power of the shared Gnd !
Motor drive:
For the mouse droid, I am still struggling on which approach to use for the wheels. I currently have a scavenged rear wheel assembly from an old R/C car that would fit (wrong wheels but that’s a detail for now) but the motor used in there is a simple 6v DC motor without ESC. I still have to figure out if I’m going to use this way or build another assembly for it. If I decide to use it, I simply have to use a MOSFET that will link the battery w/ the motor and provide power that way. It would sure work but the issue I’ll have is that I won’t have a way to use reverse on this, which is somewhat necessary if I want to use it in the end. Maybe a 2nd MOSFET w/ an inverted circuit and depending on which ‘command’ the Tx send, the proper MOSFET gets activated. Just need to be careful to not activate both at the same time 
(Read: Bzzzzttt!)
Azear's Build-Blog 