Multiwii code

Hello,

I'm building my drone but I am having some problems to set the right configuration. I have already tried to set it, but still doesn't make any variation in the PWM output.

Drone specs:

4x D2826-6 brushless motors
4x ESC's 50A mystery
1 Arduino mega + IMU gy-80
1 Futaba RC controller + receiver

This is the only thing that avoids him to fly? Or there another thing that I should look at?