File content as of revision 18:8b3efa4d4a36:

#include "mbed.h"
#include "m3pi.h"

m3pi m3pi;

//File name
#define FILESYS "robot"
#define FILENAME "/robot/data.txt"

// Minimum and maximum motor speeds
#define MAX 0.3
#define MIN 0

// PID terms
#define P_TERM 1
#define I_TERM 0
#define D_TERM 8


//typedef -> definer som type i C++
//uden typedef - det er ikke en type, så du skal skrive struct performance_data
typedef struct performance_data { //<- navn på structen
    float wh;
    int pitstops;
} performance_data;  //<- navn på typen


void write_to_file(performance_data data) {

    //Define file system
    LocalFileSystem local(FILESYS);
    
    //Make a pointer to the file
    FILE *fp = fopen(FILENAME, "w");  //"w" "r" "a"
    
    fprintf(fp, "%0.2f %d", data.wh, data.pitstops);  //write to the file
    
    fclose(fp);  //close when done.

}

performance_data read_from_file() {

    performance_data data;
    
    
    //Define file system
    LocalFileSystem local(FILESYS);
    
    //Make a pointer to the file
    FILE *fp = fopen(FILENAME, "r");  //"w" "r" "a"
    
    //Make some error prevention later
    fscanf(fp, "%f %d", &(data.wh), &(data.pitstops) );  //write to the file
    
    fclose(fp);  //close when done.
    
    return data;
   
}


void sensor_all(int arr[]) //lav en funktion? ved ikke hvad jeg skal her
     {
        m3pi.putc(0x87); // send noget sensor data
    
        for(int n=0; n < 5; n++) // forloop så sensor for data
        {
        char lowbyte = m3pi.getc();
        char hibyte  = m3pi.getc();
        arr[n] = ((lowbyte + (hibyte << 8))); // sensor value
        }
        m3pi.cls();
        m3pi.locate(0,1);
        m3pi.printf("%d", arr[0]);
        m3pi.locate(0,0);
        m3pi.printf("%d", arr[4]);
        }
 
int maze (void)
{
    
    return 1;
}   

void turn_left (void)
{
    m3pi.left(0.3);
    wait (0.22);
}
    
void turn_right (void)
{
    m3pi.right (0.3);
    wait (0.22);
}

int main() {
    
    //test the function to write to a local file
    performance_data robot_stats;
    robot_stats.wh = 120.5;
    robot_stats.pitstops = 200;
    
    write_to_file(robot_stats);
    
    performance_data new_data;
    new_data = read_from_file();
    //might get an error here due to timing
    
    
    new_data.wh = new_data.wh * 2;
    new_data.pitstops = new_data.pitstops * 2;
    
    write_to_file(new_data);
    //should get 247... and 246

    m3pi.locate(0,1);
    m3pi.printf("Line PID");

    wait(1.0);

    m3pi.sensor_auto_calibrate();

    float right;
    float left;
    float current_pos_of_line = 0.0;
    float previous_pos_of_line = 0.0;
    float derivative,proportional,integral = 0;
    float power;
    float speed = MAX;
    int sensor_val[5];
    
    
    /* if restartedFromOff: Load values from file, recalibrate and start.
    */
    
    while (1) {
      
      /*
      switch
          if nothing else: line following
          if low_batt: slow down and continue
          if atPitIntersection: increment internal lap counter
          if low_batt && atPitIntersection: Stop && execute pit navigation program
          if all_sensors == 1000 (lifted from track): 
                show Wh and pitstops on display
                stop motors, reset PID errors, wait 20 secs, recalibrate sensors
                
          if all_sensors < 90 (driven off track):
                stop and ask for help? Flash LEDs? turn back and continue? Reset PID errors
      
      Periodically (not necessarily every lap - maybe every 2-5th lap):
        Save to file -> possibly only after pit
        Check battery voltage -> every couple of minutes
        Check light sensors for drift -> recalibrate (optional)
        
      */
      
      
      
      /* Separate functions
        pit_navigation (entering pit from T-intersection all the way to the charger)
        pit_execution (only when connected to charger - voltage > V_CHARGER_MIN
            add 1 to number of pitstops
            charge and wait for signal from the external charging circuit
                during charging: integrate  v(t) dt, add to cumulative sum
            when fully charged (or signal goes high):
                Calculate delta_Wh ( integrate{ v(t) dt} * u * 1/3600 ) 
                Calculate total_Wh
                save progress data to file
            leave the charger -> pass control to pit_exit
            
        pit_exit
            reverse out of the pit back to T-intersection
            continue line following away from T-intersection, recal sensors after a few seconds
            
      
        AfterPitAdmin: Calibrate sensors, save state to file, 
          
        show_results_on_display:
          
        check_sensors_for_errors:
        
        check_battery_voltage -> return true false
            compare m3pi.battery() < V_CRITICAL
      
      
      
      HUSK FOR POKKER KOLLES KODESTANDARD!
      
      */
      
      
      // Get the position of the line.
        current_pos_of_line = m3pi.line_position();        
        proportional = current_pos_of_line;
        
        // Compute the derivative
        derivative = current_pos_of_line - previous_pos_of_line;
        
        // Compute the integral
        integral += proportional;
        
        // Remember the last position.
        previous_pos_of_line = current_pos_of_line;
        
        // Compute the power
        power = (proportional * (P_TERM) ) + (integral*(I_TERM)) + (derivative*(D_TERM)) ;
        
        // Compute new speeds   
        right = speed+power;
        left  = speed-power;
        
        // limit checks
        if (right < MIN)
            right = MIN;
        else if (right > MAX)
            right = MAX;
            
        if (left < MIN)
            left = MIN;
        else if (left > MAX)
            left = MAX;
            
       // set speed 
        m3pi.left_motor(left);
        m3pi.right_motor(right);
        
        //Marc's sensor test
        sensor_all(sensor_val); // sensor_value gets fkt value
        if (sensor_val[0] > 350 && sensor_val[4] > 350)
            {
                 
                m3pi.stop();
                turn_right();
                m3pi.stop();
                m3pi.forward(0.2);
                wait (1.1);
                m3pi.stop();
                wait (5);
                m3pi.backward(0.2);
                wait (1);
                m3pi.stop();
                turn_left();
                m3pi.stop();
            }
        /*
        sensor_value4 = sensor_all(4); // sensor_value gets fkt value
        */
            
        /*
        m3pi.printf("%d", sensor_value0); // prints one of sidesensors value
        m3pi.locate(0,1);
        m3pi.printf("%d", sensor_value4); // prints the other sidesensor value
        */

    }
}