File content as of revision 2:f0a9ecb4d049:

/*   X- Configuration
        m2   m3                      --           >
          \ /                      /    \       /
          / \                            V     |
        m1   m0                                 \
                                    ROLL       PITCH */
#include "mbed.h"
#include "LED.h"        // LEDs framework for blinking ;)
#include "PC.h"         // Serial Port via USB by Roland Elmiger for debugging with Terminal (driver needed: https://mbed.org/media/downloads/drivers/mbedWinSerial_16466.exe)

#include "IMU_10DOF.h"  // Complete IMU class for 10DOF-Board (L3G4200D, ADXL345, HMC5883, BMP085)
#include "RC_Channel.h" // RemoteControl Channels with PPM
#include "PID.h"        // PID Library (slim, self written)
#include "Servo.h"      // Motor PPM using any DigitalOut Pin

#define PPM_FREQU       495     // Hz Frequency of PPM Signal for ESCs (maximum <500Hz)
#define INTEGRAL_MAX    300     // maximal output offset that can result from integrating errors
#define RC_SENSITIVITY  30      // maximal angle from horizontal that the PID is aming for
#define YAWSPEED        1.0     // maximal speed of yaw rotation in degree per Rate
#define AILERON         0       // RC
#define ELEVATOR        1
#define RUDDER          2
#define THROTTLE        3
#define CHANNEL8        4
#define CHANNEL7        5
#define CHANNEL6        6
#define ROLL            0       // Axes
#define PITCH           1
#define YAW             2

#define SQRT2           0.7071067811865

bool  armed = false;                    // is for security (when false no motor rotates any more)
bool  debug = true;                     // shows if we want output for the computer
bool  RC_present = false;               // shows if an RC is present
float P_R = 6, I_R = 0, D_R = 0;        // PID values for the rate controller
float P_A = 1.865, I_A = 1.765, D_A = 0;// PID values for the angle controller
float PY = 3.2, IY = 0, DY = 0;         // PID values for Yaw
float RC_angle[] = {0,0,0};             // Angle of the RC Sticks, to steer the QC
float Motor_speed[4] = {0,0,0,0};       // Mixed Motorspeeds, ready to send

LED         LEDs;
PC          pc(USBTX, USBRX, 115200);   // USB
//PC          pc(p9, p10, 115200);       // Bluetooth
IMU_10DOF   IMU(p5, p6, p7, p19);
RC_Channel  RC[] = {RC_Channel(p8,1), RC_Channel(p15,2), RC_Channel(p17,4), RC_Channel(p16,3), RC_Channel(p25,2), RC_Channel(p26,4), RC_Channel(p29,3)}; // no p19/p20 !
PID         Controller_Rate[] = {PID(P_R, I_R, D_R, INTEGRAL_MAX), PID(P_R, I_R, D_R, INTEGRAL_MAX), PID(PY, IY, DY, INTEGRAL_MAX)}; // 0:X:Roll 1:Y:Pitch 2:Z:Yaw
PID         Controller_Angle[] = {PID(P_A, I_A, D_A, INTEGRAL_MAX), PID(P_A, I_A, D_A, INTEGRAL_MAX), PID(0, 0, 0, INTEGRAL_MAX)};
Servo       ESC[] = {Servo(p21,PPM_FREQU), Servo(p22,PPM_FREQU), Servo(p23,PPM_FREQU), Servo(p24,PPM_FREQU)};   // use any DigitalOit Pin

extern "C" void mbed_reset();

void executer() {
    char command = pc.getc();
    if (command == 'X')
        mbed_reset();
    if (command == '-')
        debug = !debug;
        
    if (command == 'w')
        P_R += 0.1;
    if (command == 's')
        P_R -= 0.1;
        
    if (command == 'q')
        armed = true;
    if (command == 'a')
        armed = false;
        
    pc.putc(command);
    LEDs.tilt(2);
}

int main() {
    pc.attach(&executer);
    while(1) {
        // IMU
        IMU.readAngles();
        
        // Arming / disarming
        RC_present = !(RC[AILERON].read() == -100 || RC[ELEVATOR].read() == -100 || RC[RUDDER].read() == -100 || RC[THROTTLE].read() == -100); // TODO: Failsafe
        if(RC[THROTTLE].read() < 20 && RC[RUDDER].read() > 850) {
            armed = true;
            RC_angle[YAW] = IMU.angle[YAW];
        }
        if((RC[THROTTLE].read() < 30 && RC[RUDDER].read() < 30) || !RC_present) {
            armed = false;
        }
        
        // Setting PID Values from auxiliary RC channels
        for(int i=0;i<3;i++)
            Controller_Angle[i].setPID(P_A,I_A,D_A);
        for(int i=0;i<2;i++)
            Controller_Rate[i].setPID(P_R,I_R,D_R); // give the new PID values to roll and pitch controller
        Controller_Rate[YAW].setPID(PY,IY,DY);
        
        // RC Angle ROLL-PITCH-Part
        for(int i=0;i<2;i++) {    // calculate new angle we want the QC to have
            if (RC_present)
                RC_angle[i] = (RC[i].read()-500)*RC_SENSITIVITY/500.0;
            else
                RC_angle[i] = 0;
        }

        // RC Angle YAW-Part
        float   RC_yaw_adding;                  // temporary variable to take the desired yaw adjustment
        if (RC_present && RC[THROTTLE].read() > 20)
            RC_yaw_adding = -(RC[RUDDER].read()-500)*YAWSPEED/500;  // the yaw angle is integrated from stick input
        else
            RC_yaw_adding = 0;
        
        RC_angle[YAW] = RC_angle[YAW] + RC_yaw_adding < -180 ? RC_angle[YAW] + 360 + RC_yaw_adding : RC_angle[YAW] + RC_yaw_adding; // make shure it's in the cycle -180 to 180
        RC_angle[YAW] = RC_angle[YAW] + RC_yaw_adding > 180 ? RC_angle[YAW] - 360 + RC_yaw_adding : RC_angle[YAW] + RC_yaw_adding;
        

        // Controlling
        for(int i=0;i<2;i++) {
            Controller_Rate[i].setIntegrate(armed); // only integrate in controller when armed, so the value is not totally odd from not flying
            Controller_Rate[i].compute((RC[i].read()-500.0)*100.0/500.0, IMU.mpu.Gyro[i]); // give the controller the actual gyro values and get his advice to correct
        }
        Controller_Rate[2].setIntegrate(armed); // only integrate in controller when armed, so the value is not totally odd from not flying
        if (RC[THROTTLE].read() > 20)
            Controller_Rate[2].compute(-(RC[2].read()-500.0)*100.0/500.0, IMU.mpu.Gyro[2]); // give the controller the actual gyro values and get his advice to correct
        else
            Controller_Rate[2].compute(0, IMU.mpu.Gyro[2]); // give the controller the actual gyro values and get his advice to correct
        
        
        // Mixing
        Motor_speed[0] = RC[THROTTLE].read()   +SQRT2*Controller_Rate[ROLL].Value  -SQRT2*Controller_Rate[PITCH].Value;  // X Configuration
        Motor_speed[1] = RC[THROTTLE].read()   -SQRT2*Controller_Rate[ROLL].Value  -SQRT2*Controller_Rate[PITCH].Value;  // 
        Motor_speed[2] = RC[THROTTLE].read()   -SQRT2*Controller_Rate[ROLL].Value  +SQRT2*Controller_Rate[PITCH].Value;  // 
        Motor_speed[3] = RC[THROTTLE].read()   +SQRT2*Controller_Rate[ROLL].Value  +SQRT2*Controller_Rate[PITCH].Value;  // 
        
        Motor_speed[0] -= Controller_Rate[YAW].Value;
        Motor_speed[2] -= Controller_Rate[YAW].Value;
        Motor_speed[3] += Controller_Rate[YAW].Value;
        Motor_speed[1] += Controller_Rate[YAW].Value;
        
        if (armed) // for SECURITY!
        {       
                debug = false;
                // PITCH
                //ESC[0] = (int)Motor_speed[0]>50 ? (int)Motor_speed[0] : 50;
                //ESC[2] = (int)Motor_speed[2]>50 ? (int)Motor_speed[2] : 50;
                // ROLL
                //ESC[1] = (int)Motor_speed[1]>50 ? (int)Motor_speed[1] : 50;
                //ESC[3] = (int)Motor_speed[3]>50 ? (int)Motor_speed[3] : 50;
                for(int i=0;i<4;i++)   // Set new motorspeeds
                    ESC[i] = (int)Motor_speed[i]>50 ? (int)Motor_speed[i] : 50;
                
        } else {
            for(int i=0;i<4;i++) // for security reason, set every motor to zero speed
                ESC[i] = 0;
            debug = true;
        }
        
        if (debug) {
            pc.printf("$STATE,%d,%.3f\r\n", armed, IMU.dt);
            //pc.printf("$RC,%d,%d,%d,%d,%d,%d,%d\r\n", RC[AILERON].read(), RC[ELEVATOR].read(), RC[RUDDER].read(), RC[THROTTLE].read(), RC[CHANNEL6].read(), RC[CHANNEL7].read(), RC[CHANNEL8].read());
            pc.printf("$GYRO,%.3f,%.3f,%.3f\r\n", IMU.mpu.Gyro[ROLL], IMU.mpu.Gyro[PITCH], IMU.mpu.Gyro[YAW]);
            //pc.printf("$ACC,%.3f,%.3f,%.3f\r\n", IMU.mpu.Acc[ROLL], IMU.mpu.Acc[PITCH], IMU.mpu.Acc[YAW]);
            //pc.printf("$ANG,%.3f,%.3f,%.3f\r\n", IMU.angle[ROLL], IMU.angle[PITCH], IMU.angle[YAW]);
            //pc.printf("$RCANG,%.3f,%.3f,%.3f\r\n", RC_angle[ROLL], RC_angle[PITCH], RC_angle[YAW]);
            pc.printf("$CONT,%.3f,%.3f,%.3f,%.3f,%.3f,%.3f\r\n", Controller_Rate[ROLL].Value, Controller_Rate[PITCH].Value, Controller_Rate[YAW].Value, P_R, I_R, D_R);
            pc.printf("$MOT,%d,%d,%d,%d\r\n", (int)Motor_speed[0], (int)Motor_speed[1], (int)Motor_speed[2], (int)Motor_speed[3]);

            wait(0.04);
        }

        LEDs.rollnext();
    }
}