File content as of revision 0:3960679bf525:

#pragma once

#include "mbed.h"

// pin assignment
#define ESP_RX      PA_9
#define ESP_TX      PA_10
#define ESP_RESET   PA_12
#define QTR_13      PB_0
#define ESP_CHPD    PB_7
#define DRV_BENBL   PB_6
#define QTR_11      PB_1
#define DRV_BPHASE  PF_0
#define QTR_CTL     PF_1
#define ESP_GPIO0   PA_8
#define DRV_APHASE  PA_11
#define QTR_9       PA_7
#define DRV_AENBL   PA_4
#define QTR_7       PA_3
#define QTR_5       PA_1
#define QTR_3       PA_0

// motor driver PWM frequency
#define PWM_FREQUENCY   32.0e3f
#define PWM_PERIOD      1.0f / PWM_FREQUENCY

// number of sensors on QTR module
#define SENSORS_BAR_SIZE 6

// hysteresis thresholds for analog sensors
#define QTR_THRESHOLD_HIGH  (uint32_t) 5000U
#define QTR_THRESHOLD_LOW   (uint32_t) 20000U

// PID parameters
#define PID_SETPOINT 0.0f
#define PID_KP 0.3f
#define PID_KD 0.0f
#define PID_KI 0.0001f

class Motor
{
  public:
    Motor(const PinName &_in1Pin, const PinName &_in2Pin, const bool _brake = false);
    void setSpeed(const float speed);
    void setBrake(const bool _brake);

  private:
    PwmOut in1PWM;
    PwmOut in2PWM;
    bool brake;
};

class QTR
{
  public:
    // QTR CTL pin, array of analog inputs connected to sensor bar, number of pulses applied to CTL pin
    QTR(DigitalOut &_ctl, AnalogIn (&_sensors)[SENSORS_BAR_SIZE], const uint32_t dimPulses = 0);

    // dim sensors by applying pulses on CTL pin
    void dim(const uint32_t pulses);

    // returns digitized sensor values as bits of an uint32_t
    // a bit of 0 means that the corresponding sensor detects a reflective surface
    // index 0 in sensors array corresponds to LSB in returned value
    // uses hysteresis to reduce noise
    uint32_t readSensorsAsDigital();

    // return line position as a float between -1.0 (left) and 1.0 (right)
    float readSensorsAsFloat();

  private:
    DigitalOut &ctl;
    AnalogIn (&sensors)[SENSORS_BAR_SIZE];
    uint32_t lastSensorState;
};