Hi @robolink_leila,
I had tried, but it is still not working 
The following code is executed. Although the drone gradually went to a higher level, it was still hopping against the floor and cannot hover.
from CoDrone.codrone import *
if __name__ == '__main__':
drone = CoDrone()
drone.pair(drone.Nearest, "/dev/ttyUSB0")
# Fly 1500mm away from bottom and hover
drone.takeoff()
drone.go_to_height(2000)
drone.land()
Hi @robolink_leila,
Thank you for the call on Tuesday. Since I am not allowed to buy the updated version of CoDrone, may I have the old firmware that capable with the old flow sensor?
Thank you for the prompt reply. I had tried to fly again on a floor covered with cotton cloth after switching the motors, but I still encountered the same problem as before. Sure, I would be happy to set up a call if time allows (I am from Hong Kong).
Hi,
I found my drone keeps bouncing along the ground and drifting in one direction when I use the "takeoff" command in the official mobile app ("Petrone"). I had tried to trim the drone but it still cannot fly upwards, except I keep pressing the "throttle" in the mobile controller (but it cannot hover).
I had also tried to calibrate the drone. Yet, it just hopped once and drifted again. Its LED blinked yellowish green at last.
The following videos show how the calibration goes:
https://drive.google.com/drive/folders/16k_T26cYZuUcO_PPJx71CEiEkd3XgxZP?usp=sharing
How could I solve the issue?
p.s. I had checked the motor and propellers and tested with full battery.