Setting PID (Proportional-Integral-Derivative) values for a quadcopter involves tuning the parameters to achieve stable flight characteristics. Here’s a basic overview of the process:

1. Understand the PID Controller: Each component of the PID controller affects the behavior of the quadcopter:
   • Proportional (P): Directly adjusts the motor output in response to the error (the difference between desired and actual orientation).
   • Integral (I): Integrates the error over time and helps in eliminating steady-state errors, such as those caused by wind.
   • Derivative (D): Predicts future error by considering its rate of change and helps in reducing overshoot and oscillations.
2. Start with Default Values: Most flight controllers come with default PID values. These values are typically a good starting point for tuning. If your quadcopter is flying reasonably well with these defaults, you may not need to make significant adjustments.
3. Manual Tuning:
   • Proportional (P): Start by increasing the P value until the quadcopter exhibits oscillations or instability. Then, reduce it slightly until the oscillations dampen.
   • Integral (I): Increase I value to eliminate any steady-state errors. However, be cautious as too much I can lead to overshoot or instability.
   • Derivative (D): Gradually increase D to dampen oscillations and reduce overshoot. Be careful not to set it too high, as it can cause instability.
4. Test and Refine: After adjusting each parameter, test the quadcopter’s flight performance. Monitor for oscillations, overshoot, and response to control inputs. Refine the values iteratively until you achieve the desired stability and responsiveness.
5. Consider Flight Modes: PID values might need adjustment depending on the flight mode (e.g., stabilized, acrobatic). You may need different settings for different modes to optimize performance.
6. Use Tuning Software: There are various tuning software tools available that can assist in PID tuning by providing real-time feedback on the quadcopter’s response to parameter changes. Examples include Betaflight, Cleanflight, or even custom MATLAB scripts.
7. Document Changes: Keep track of the changes you make to the PID values and their effects on flight performance. This documentation will help you revert to previous settings if needed and serve as a reference for future tuning sessions.
8. Be Patient: PID tuning can be time-consuming and requires patience. Small incremental adjustments are key to finding the optimal values without destabilizing the quadcopter.

Remember, PID tuning is somewhat of an art and requires experimentation and observation to find the right balance for your specific quadcopter and flying style.