Android controlled RC Car

Check out my project here:

My question: I am having a delay between the computer's signal being sent and the motors kicking in. Any ideas on making things go a little faster between the android and the arduino?

Also, I am having some noise when reading the frequency within the arduino. Any ideas on another method to communicating via 3.5mm jack between arduino and the android phone? I considered FFT, FSK, and ASK. Plz let me know which is best since I dont have much processing power...

Thanks, Rohit

It looks like you have made a home-made data link using pulses over a loop. How much latency are you getting just over the data link? I'm not clear how your solution works but assuming you do have two wires isn't that enough to use a conventional serial bitstream?

What is conventional serial bitstream? I have it doing frequency modulation so the frequency changes from high to low for 1's and 0's but is there a better way to do it? I did consider doing amplitude modulation but there is too much noise. Is there a way to do FFT on an arduino without killing the speed?

When I saw this today

I said, "Hey, I've seen that before."

rkrishnan2012: What is conventional serial bitstream?

I mean just using a DC pulse train. Unless you're going for huge data rates or distances, why you you need to encode it on a carrier?