I have built an Arduino DUE based quadcopter and I am using HC-12 as a transmitter and receiver between my laptop and the quadcopter. What am I doing is just send a speed value from my laptop and apply that value to all the quadcopter motors wirelessly. The problem is my quadcopter is flipping while trying to go up. Watch this video here to get an idea of what I mean. I had tried to make the quadcopter balanced and I got the same problem. By the way, I tried to change the motors and tried many ways to balance it and to make the center of gravity in the center of the quadcopter but I faced the same problem of flipping. I need to make the quadcopter go up normally without control and flipping just by giving the value of the motors speed from the laptop without RC.
Edit: Now I rebuilt it and recalibrated the ESCs after that, I got this result. My quadcopter seems to be hovering from 3 sides and the last one can't hover for the same speed. I tried to increase the speed of that motor and change the motor but I got no difference.