Drone-FabAcademy-2025/docs/final_project/drone_code.md

# Coding the drone

## What does every part of my code do?
### #include
`#include` includes an external library into the project so you can use it.

//TODO: add docs about working code not broken code

## Issues

### Using the wrong library for the BNO085
First used the wrong library I used the Adafruit bno0xx library instead of the Sparkfun bno08x library. The Example script below this reads the BNO085 sensor and returns the values in the arduino serial console.

??? failure

    ```cpp
    #include "conf.h"
    #include <Adafruit_BNO08x.h>
    #include <sh2.h>
    #include <sh2_SensorValue.h>
    #include <sh2_err.h>
    #include <sh2_hal.h>
    #include <sh2_util.h>
    #include <shtp.h>

    Adafruit_BNO08x bno08x(BNOINTERRUPTSIG);
    sh2_SensorValue_t sensorValue;

    void setup() {
    Serial.begin(9600);
    Serial.println("setup started");
    // Setup all ESC
    // ledcAttach(MOTOR1, PWMFREQ, PWMRESOLUTION);
    // ledcAttach(MOTOR2, PWMFREQ, PWMRESOLUTION);
    // ledcAttach(MOTOR3, PWMFREQ, PWMRESOLUTION);
    // ledcAttach(MOTOR4, PWMFREQ, PWMRESOLUTION);
    Serial.print("Setup Started");
    }

    void loop() {
    // put your main code here, to run repeatedly:
    sleep(3)
    if (!bno08x.begin_I2C()) {
        Serial.println("Failed to find BNO08x chip");
        sleep(1);
    }


    Serial.print("Game Rotation Vector - r: ");
    Serial.print(sensorValue.un.gameRotationVector.real);
    Serial.print(" i: ");
    Serial.print(sensorValue.un.gameRotationVector.i);
    Serial.print(" j: ");
    Serial.print(sensorValue.un.gameRotationVector.j);
    Serial.print(" k: ");
    Serial.println(sensorValue.un.gameRotationVector.k);
    }

    //https://randomnerdtutorials.com/esp32-pwm-arduino-ide/
    //https://github.com/adafruit/Adafruit_BNO08x/blob/master/examples/rotation_vector/rotation_vector.ino#L25
    ```

??? example

    ```cpp
    #include <SparkFun_BNO080_Arduino_Library.h>
    #include <Wire.h>
    #include "conf.h"

    BNO080 myIMU;

    void setup() {
    Serial.begin(9600);
    Serial.println("setup started");
    // Setup all ESC
    // ledcAttach(MOTOR1, PWMFREQ, PWMRESOLUTION);
    // ledcAttach(MOTOR2, PWMFREQ, PWMRESOLUTION);
    // ledcAttach(MOTOR3, PWMFREQ, PWMRESOLUTION);
    // ledcAttach(MOTOR4, PWMFREQ, PWMRESOLUTION);
    Serial.print("Setup Started");

    Wire.begin();
    myIMU.begin();
    Wire.setClock(400000);           //Increase I2C data rate to 400kHz
    myIMU.enableRotationVector(50);  //Send data update every 50ms}
    }


    void loop() {

    if (myIMU.dataAvailable() == true) {
        float roll = (myIMU.getRoll()) * 180.0 / PI;    // Convert roll to degrees
        float pitch = (myIMU.getPitch()) * 180.0 / PI;  // Convert pitch to degrees
        float yaw = (myIMU.getYaw()) * 180.0 / PI;      // Convert yaw / heading to degrees

        Serial.print(roll, 1);
        Serial.print(F(","));
        Serial.print(pitch, 1);
        Serial.print(F(","));
        Serial.print(yaw, 1);

        Serial.println();
    }
    }
    void calibrateESC() {
    ledcWrite(MOTOR1, 1100);
    ledcWrite(MOTOR2, 1100);
    ledcWrite(MOTOR3, 1100);
    ledcWrite(MOTOR4, 1100);
    }

    //https://randomnerdtutorials.com/esp32-pwm-arduino-ide/
    //https://github.com/sparkfun/SparkFun_BNO080_Arduino_Library/blob/main/examples/Example24-UncalibratedGyro/Example24-UncalibratedGyro.ino
    ```

## New driver
After researching for a while and looking through other fab academy projects I found out that other people also made drones with micro controllers and used a pre-made driver that they customized (https://fab.cba.mit.edu/classes/863.23/Architecture/people/Zhixing/finalproject.html). After doing some research on how to keep the drone upright I also decided to use an existing driver because the math required for that is way above my level.

### The new driver
Im gonna be using the [dRhemFlightVTOL](https://github.com/nickrehm/dRehmFlight/tree/master) driver. The only problem is that it doesn't support my Inertial measuring unit (BNO085). So I will have to customize the driver to make it work with it.


//TODO: reverse engineer the driver and see what all pwm channels do from the controller
//TODO: See if i can use playstation controller as RC controller

```cpp
  thro_des = (channel_1_pwm - 1000.0) / 1000.0;  // Between 0 and 1
  roll_des = (channel_2_pwm - 1500.0) / 500.0;   // Between -1 and 1
  pitch_des = (channel_3_pwm - 1500.0) / 500.0;  // Between -1 and 1
  yaw_des = (channel_4_pwm - 1500.0) / 500.0;    // Between -1 and 1
```