Bluetooth tank V2

UPDATE

After some research and tests I came up with driver setup.

I am going to use two L298N drivers with heatsink modification. Made some test drive and I am happy with result(it is so fast even in "low" gear :) compared with Tamiya gearbox), but I need to buy one more driver becouse second one is made by me for some testing, here is test drive photo. Will do video after eveything is more user friendly.

And conclusion is that L298N can drive one 12V drill motor with gearbox + tank weight or 4A load.

more photos 

https://picasaweb.google.com/106462055291066309187/September302012ArduinoBluetoothTankRobotNewChassisVersion

UPDATE

I have made new chassis frame and Tamiya gearbox changed with two 12v drill motors(makita 6270d). But as I expected 298N driver is too weak for those motors. When I turn pwm to full power I can hear only sound from motors (input is ~ 9v but output in each motor at that moment is ~ 0.8v - 1v).

Problem is that I dont know any characteristics about those motors. So I dont know what driver should I use.

Here is first version:

https://www.robotshop.com/letsmakerobots/node/33146

So after I have received Arduino Uno clone from dx.com, I decided to upgrade my Bluetooth tank = add speed control (pwm signals) and of-course use android device accelerometer to control tank direction and speed. After msp430 platform, Arduino is so easy to program. And here is results. First video is how it looks when using tablet to control :D, normally I use Desire S(much easier, Desire was used to make those videos, has better camera). In this video I think my samsung tablet is upside down :). Second video: shows climbing performance :D and super truper cover :DDD