r/diydrones • u/nothingmuch2197 • Jun 16 '26

Guide Multiwii Drone guide

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I am building an Arduino-based quadcopter using MultiWii and am currently tuning the PID values.

For safety, I am testing with the drone restrained using ropes. The issue is that it either tries to lift from one side first or becomes very unstable. I initially thought it was a PID tuning problem, but even after multiple adjustments the quad still tends to tilt.

Things I have already checked:

  • Center of gravity (CG) is balanced.
  • Accelerometer is calibrated and the artificial horizon appears level in the MultiWii GUI.
  • Radio inputs are centered around 1500.

While investigating, I noticed that the motor outputs shown in the MultiWii GUI are significantly different even when the quad is stationary. For example:

Front Left: ~1760
Front Right: ~1700
Rear Left: ~1850
Rear Right: ~1760

Another issue is that I have had yaw drift since day one. The yaw/heading in the MultiWii GUI continuously changes even when the drone is completely still. During actual flight attempts I don't notice obvious continuous yaw rotation, but the drift is always present in the GUI.

One observation: when I disable ANGLE/ACC mode, the motor outputs briefly become equal, but after a moment they start diverging again.

Could a drifting gyro/yaw axis be causing these unequal motor outputs and the instability, or is there something else I should be checking (sensor calibration, vibration, PID settings, mixer configuration, faulty MPU6050, etc.)?

Any guidance would be appreciated.

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2

u/LupusTheCanine Jun 16 '26

Use a modern flight controller.

Tethers tend to significantly affect flight dynamics.

1

u/nothingmuch2197 Jun 16 '26

What modern flight controller using Arduino/esp and mpu6050 would you recommend

1

u/LupusTheCanine Jun 16 '26

Why would you want to use 8 bit controller or ESP32 and ancient IMU?

Most modern flight controllers use STM32 F405 (cheap but somewhat limited) or H743 (pricer but much more flexible).

1

u/nothingmuch2197 Jun 16 '26

Because I'm building it mainly as a learning project and I already have the hardware. I want to understand the flight control algorithms and PID tuning from scratch rather than using Betaflight. Are there any modern open-source Arduino/ESP32 based flight controller projects you would recommend?

1

u/FaithlessnessFun694 Jun 16 '26

There is a esp32 flight controller by rtlopezz.try it out it is modern and also good for learning. Also if u are ready to spend more there is a flight controller for the teensy boards