File content as of revision 2:82a11e992619:

#include "mbed.h"
#include "AVEncoder.h"

// set things
Serial pc(SERIAL_TX, SERIAL_RX);
Ticker Systicker;
Timer timer;

PwmOut right_forward(PB_10);
PwmOut right_reverse(PA_6);
PwmOut left_forward(PA_7);
PwmOut left_reverse(PB_6);

// TODO: change our encoder pins from AnalogIn into:
// otherwise, we can also use the AVEncoder thing as well.  
AVEncoder l_enco(PA_15, PB_3);
AVEncoder r_enco(PA_1, PA_10);

// gyro
AnalogIn _gyro(PA_0);
// AnalogIn gyro_cal(PC_1) ?? currently this isn't connected. 

//Left Front IR
DigitalOut eLF(PC_3);
AnalogIn rLF(PC_0);
                                                    //PC_4 is an ADC
//Left Side IR
DigitalOut eLS(PC_2);
AnalogIn rLS(PC_1);

//Right Front IR
DigitalOut eRF(PC_12);
AnalogIn rRF(PA_4);

//Right Side IR
DigitalOut eRS(PC_15);
AnalogIn rRS(PB_0);

DigitalOut myled(LED1);

volatile float gyro_offset = 0;

volatile float line_prevError = 0;
volatile float enco_prevError = 0;
volatile float gyro_prevError = 0;

volatile float line_accumulator = 0;
volatile float line_decayFactor = 1;
volatile float enco_accumulator = 0;
volatile float enco_decayFactor = 1.2;
volatile float gyro_accumulator = 0;
volatile float gyro_decayFactor = 1.2;

volatile float set_speed = 0.5;
volatile float left_speed = 0.5;
volatile float right_speed = 0.5;

const float left_max_speed = 6; // max speed is 6 encoder pulses per ms.
const float right_max_speed = 6.2; 

const float gyro_propo = 6.5;
const float gyro_integ = 0;
const float gyro_deriv = 10;

const float enco_propo = .0005;
const float enco_integ = 0;
const float enco_deriv = .0002;

const float spin_enco_weight = 0.75;
const float spin_gyro_weight = 1 - spin_enco_weight;

const float frontWall = 0.7; //need to calibrate this threshold to a value where mouse can stop in time
//something like this may be useful 

volatile float enco_error;
volatile float enco_pid;
volatile float gyro_error;
volatile float gyro_pid;
volatile float w_error;

// this is just so that we can maintain what state our mouse is in. 
// currently this has no real use, but it may in the future. 
// or we could just remove this entirely. 
typedef enum 
{
    STOPPED, 
    FORWARD, 
    TURNING, 
    UNKNOWN
} STATE;
volatile STATE mouse_state;

void watchOut();
void offsetCalc();
void stop();

void reset()
{
    l_enco.reset();
    r_enco.reset();
}

void systick()
{
    watchOut();
    if ( mouse_state == STOPPED )
    {
        offsetCalc();
        stop();
        return;
    }
    
    enco_error = l_enco.getPulses() - r_enco.getPulses();
    gyro_error = _gyro.read() - gyro_offset;
    
    enco_accumulator += enco_error;
    gyro_accumulator += gyro_error;
    
    enco_pid = 0;
    enco_pid += enco_propo * enco_error;
    enco_pid += enco_integ * enco_accumulator;
    enco_pid += enco_deriv * (enco_error - enco_prevError);
    
    gyro_pid = 0;
    gyro_pid += gyro_propo * gyro_error;
    gyro_pid += gyro_integ * gyro_accumulator;
    gyro_pid += gyro_deriv * (gyro_error - gyro_prevError);
    
    w_error = spin_enco_weight * enco_pid + spin_gyro_weight * gyro_pid;
    left_speed = set_speed + w_error;
    right_speed = set_speed - w_error;
    
    left_forward = left_speed / left_max_speed;
    left_reverse = 0;
    right_forward = right_speed / right_max_speed;
    right_reverse = 0;
    
    enco_prevError = enco_error;
    gyro_prevError = gyro_error;
    
    enco_accumulator += enco_error;
    gyro_accumulator += gyro_error;
    
    enco_accumulator /= enco_decayFactor;
    gyro_accumulator /= gyro_decayFactor;
    
    //reset();
}

// computes gyro_offset
// uses a "weighted" average. 
// idea is that the current gyro offset is weighted more than previous ones. 
    // uses the following y(n) = 1/2 * y(n-1) + 1/2 * x(n). 
    // (therefore y(n) = sum of x(i)/2^i from i from 0 to n.)
    // this maintains that there will be some influence from previous factors, but keeps the current value at a higher weight.
// currently this is only in the setup function. we can run this when the mouse is running in a line
// when we figure out good line running pid.
void offsetCalc()
{
    gyro_offset = gyro_offset / 2 + _gyro.read() / 2;
}


void stop()
{
    left_forward = 1;
    left_reverse = 1;
    right_forward = 1;
    right_reverse = 1;
}
    
void watchOut()
{
    eRF = 1;
    float right = rRF.read();
    eRF = 0;
    eLF = 1;
    float left = rLF.read();
    eLF = 0;
    if(left > frontWall || right > frontWall)
    {
        mouse_state = STOPPED;
    }
}


void setup()
{
    pc.printf("Hello World\r\n");
    
    eRS = 0;
    eRF = 0;
    eLS = 0;
    eLF = 0;
    
    mouse_state = FORWARD;
    
    myled = 1;
    
    for ( int i = 0; i < 1000; i++ )
    {
        offsetCalc();
    }
    
    //left_forward = left_speed / left_max_speed;
//    left_reverse = 0;
//    right_forward = right_speed / right_max_speed;
//    right_reverse = 0;
    
    wait(2);
    
    // repeat this for some time frame. 
    Systicker.attach_us(&systick, 1000);
}
    

int main() {
    setup();
    while(1) {
        
        pc.printf("enco_pid: %f, gyro_pid: %f, w_error: %f\r\n", enco_pid, gyro_pid, w_error);
        //wait(1);
    }
}