# Is my quadcopter loop fast enough?

I've been working on a quad copter for awhile now, recently I've finished the interface for PID tuning and its leading me to question several design decisions.

The quad uses a RaspberryPi as its pilot, the entire loop takes less than 20ms. IMU data is gathered, the throttle speeds are calculated, and then finally sent to an Arduino(micro) over an SPI interface. Where they are analogWrite(...), to each ESC.

Can a quadcopter fly with a loop that slow? 20ms = 50Hz?

• in my application runs at 100 Hz (attitude controller), but in many papers I found up to 1 kHz. Pay attention that the update frequency of the velocity give by your GPS could lead to problems. It runs very slowly compared to the rest of the system. – Dave Jan 1 '15 at 8:36