File content as of revision 42:b54a4f294aa9:

#include <mbed.h>
#include <math.h>

#include "PM2_Libary.h"
#include "Eigen/Dense.h"

# define M_PI 3.14159265358979323846  // number pi

// logical variable main task
bool do_execute_main_task = false;  // this variable will be toggled via the user button (blue button) to or not to execute the main task

// user button on nucleo board
Timer user_button_timer;            // create Timer object which we use to check if user button was pressed for a certain time (robust against signal bouncing)
InterruptIn user_button(PC_13);     // create InterruptIn interface object to evaluate user button falling and rising edge (no blocking code in ISR)
void user_button_pressed_fcn();     // custom functions which gets executed when user button gets pressed and released, definition below
void user_button_released_fcn();

// while loop gets executed every main_task_period_ms milliseconds
int main_task_period_ms = 10;   // define main task period time in ms e.g. 50 ms -> main task runns 20 times per second
Timer main_task_timer;          // create Timer object which we use to run the main task every main task period time in ms

// led on nucleo board
DigitalOut user_led(LED1);      // create DigitalOut object to command user led

// Sharp GP2Y0A41SK0F, 4-40 cm IR Sensor
float ir_distance_mV = 0.0f;    // define variable to store measurement
AnalogIn ir_analog_in(PC_2);    // create AnalogIn object to read in infrared distance sensor, 0...3.3V are mapped to 0...1

// 78:1, 100:1, ... Metal Gearmotor 20Dx44L mm 12V CB
DigitalOut enable_motors(PB_15);    // create DigitalOut object to enable dc motors

float   pwm_period_s = 0.00005f;    // define pwm period time in seconds and create FastPWM objects to command dc motors
FastPWM pwm_M1(PB_13);              // motor M1 is closed-loop speed controlled (angle velocity)
FastPWM pwm_M2(PA_9);               // motor M2 is closed-loop speed controlled (angle velocity)

EncoderCounter  encoder_M1(PA_6, PC_7); // create encoder objects to read in the encoder counter values
EncoderCounter  encoder_M2(PB_6, PB_7);

// create SpeedController and PositionController objects, default parametrization is for 78.125:1 gear box
float max_voltage = 12.0f;                  // define maximum voltage of battery packs, adjust this to 6.0f V if you only use one batterypack
float counts_per_turn = 20.0f * 78.125f;    // define counts per turn at gearbox end: counts/turn * gearratio
float kn = 180.0f / 12.0f;                  // define motor constant in rpm per V
float k_gear = 100.0f / 78.125f;            // define additional ratio in case you are using a dc motor with a different gear box, e.g. 100:1
float kp = 0.1f;                            // define custom kp, this is the default speed controller gain for gear box 78.125:1

SpeedController speedController_M1(counts_per_turn, kn, max_voltage, pwm_M1, encoder_M1); // default 78.125:1 gear box  with default contoller parameters
SpeedController speedController_M2(counts_per_turn, kn, max_voltage, pwm_M2, encoder_M2); // default 78.125:1 gear box  with default contoller parameters
// SpeedController speedController_M2(counts_per_turn * k_gear, kn / k_gear, max_voltage, pwm_M2, encoder_M2); // parameters adjusted to 100:1 gear

// sparkfun line follower array
I2C i2c(PB_9, PB_8); // I2C (PinName sda, PinName scl)
SensorBar sensor_bar(i2c, 0.1175f);

// transformations and stuff
float r_wheel = 0.0358f / 2.0f;
float L_wheel = 0.143f;
Eigen::Matrix<float, 2, 2> Cwheel2robot; // transform wheel to robot
Eigen::Matrix<float, 2, 2> Crobot2wheel; // transform robot to wheel
Eigen::Matrix<float, 2, 1> robot_coord;  // contains v and w
Eigen::Matrix<float, 2, 1> wheel_speed;  // w1 w2

float fcn_vel_cntrl(const float& vel_max, const float& vel_min, const float& ang_max, const float& ang);
float fcn_ang_cntrl(const float& Kp, const float& Kp_nl, const float& ang);

int main()
{    
    // attach button fall and rise functions to user button object
    user_button.fall(&user_button_pressed_fcn);
    user_button.rise(&user_button_released_fcn);

    // start timer
    main_task_timer.start();

    // enable hardwaredriver dc motors: 0 -> disabled, 1 -> enabled
    enable_motors = 1;

    // initialise matrizes and vectros
    Cwheel2robot << r_wheel / 2.0f   ,  r_wheel / 2.0f   ,
                    r_wheel / L_wheel, -r_wheel / L_wheel;
    Crobot2wheel << 1.0f / r_wheel,  L_wheel / (2.0f * r_wheel),
                    1.0f / r_wheel, -L_wheel / (2.0f * r_wheel);
    robot_coord << 0.06f, 0.0f;
    wheel_speed << 0.0f, 0.0f;

    while (true) { // this loop will run forever

        main_task_timer.reset();

        if (do_execute_main_task) {

            // read SensorBar
            float sensor_bar_avgAngleRad = 0.0f;
            if (sensor_bar.isAnyLedActive()) {
                sensor_bar_avgAngleRad = sensor_bar.getAvgAngleRad();
            }

            // proportional controller for angle
            //robot_coord(1) = 3.0f * sensor_bar_avgAngleRad;
            // robot_coord(0) = fcn_vel_cntrl(0.10f, 0.02f, 27.0f * M_PI / 180.0f, sensor_bar_avgAngleRad);
            // robot_coord(1) = fcn_ang_cntrl(2.0f, 5.0f, sensor_bar_avgAngleRad);
            const static float vel_max = 0.30f; //0.10f;
            const static float vel_min = 0.02f; //0.02f;
            const static float ang_max = 27.0f * M_PI / 180.0f;
            robot_coord(0) = fcn_vel_cntrl(vel_max, vel_min, ang_max, sensor_bar_avgAngleRad);
            const static float Kp = 2.0f; //2.0f;
            const static float Kp_nl = 17.0f; //10.0f; //5.0f;
            robot_coord(1) = fcn_ang_cntrl(Kp, Kp_nl, sensor_bar_avgAngleRad);

            // transform to robot coordinates
            wheel_speed = Crobot2wheel * robot_coord;

            // read analog input
            ir_distance_mV = 1.0e3f * ir_analog_in.read() * 3.3f;

            //speedController_M1.setDesiredSpeedRPS(1.0f); // set a desired speed for speed controlled dc motors M1
            //speedController_M2.setDesiredSpeedRPS(1.0f); // set a desired speed for speed controlled dc motors M2
            speedController_M1.setDesiredSpeedRPS(wheel_speed(0) / (2.0f * M_PI)); // set a desired speed for speed controlled dc motors M1
            speedController_M2.setDesiredSpeedRPS(wheel_speed(1) / (2.0f * M_PI)); // set a desired speed for speed controlled dc motors M2

            /*
            uint8_t sensor_bar_raw_value = sensor_bar.getRaw();
            for( int i = 7; i >= 0; i-- ) {
                printf("%d", (sensor_bar_raw_value >> i) & 0x01);
            }
            printf(", ");
            */
            
            /*
            int8_t sensor_bar_binaryPosition = sensor_bar.getBinaryPosition();       
            printf("%d, ", sensor_bar_binaryPosition);

            uint8_t sensor_bar_nrOfLedsActive = sensor_bar.getNrOfLedsActive();
            printf("%d, ", sensor_bar_nrOfLedsActive);
            
            float sensor_bar_angleRad = 0.0f;
            float sensor_bar_avgAngleRad = 0.0f;
            if (sensor_bar.isAnyLedActive()) {
                sensor_bar_angleRad = sensor_bar.getAngleRad();
                sensor_bar_avgAngleRad = sensor_bar.getAvgAngleRad();
            }
            printf("%f, ", sensor_bar_angleRad * 180.0f / M_PI);
            printf("%f, ", sensor_bar_avgAngleRad * 180.0f / M_PI);
            */

            printf("%f, %f\r\n", wheel_speed(0) / (2.0f * M_PI), wheel_speed(1) / (2.0f * M_PI));

        } else {

            ir_distance_mV = 0.0f;

            speedController_M1.setDesiredSpeedRPS(0.0f);
            speedController_M2.setDesiredSpeedRPS(0.0f);
        }

        user_led = !user_led;

        // do only output via serial what's really necessary (this makes your code slow)
        // printf("%d, %d\r\n", sensor_bar_raw_value_time_ms, sensor_bar_position_time_ms);

        // read timer and make the main thread sleep for the remaining time span (non blocking)
        int main_task_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(main_task_timer.elapsed_time()).count();
        thread_sleep_for(main_task_period_ms - main_task_elapsed_time_ms);
    }
}

void user_button_pressed_fcn()
{
    user_button_timer.start();
    user_button_timer.reset();
}

void user_button_released_fcn()
{
    // read timer and toggle do_execute_main_task if the button was pressed longer than the below specified time
    int user_button_elapsed_time_ms = std::chrono::duration_cast<std::chrono::milliseconds>(user_button_timer.elapsed_time()).count();
    user_button_timer.stop();
    if (user_button_elapsed_time_ms > 200) {
        do_execute_main_task = !do_execute_main_task;
    }
}

float fcn_vel_cntrl(const float& vel_max, const float& vel_min, const float& ang_max, const float& ang)
{
    const static float gain = (vel_min - vel_max) / ang_max;
    const static float offset = vel_max;
    return gain * fabs(ang) + offset;
}

float fcn_ang_cntrl(const float& Kp, const float& Kp_nl, const float& ang)
{
    float retval = 0.0f;
    if (ang > 0) {
        retval = Kp * ang + Kp_nl * ang * ang;
    } else if (ang < 0) {
        retval = Kp * ang - Kp_nl * ang * ang;
    }
    return retval;
}