encoder_diffbot.h

Go to the documentation of this file.

/*
 * Author: Franz Pucher
 */
 
#ifndef DIFFBOT_ENCODER_H
#define DIFFBOT_ENCODER_H
 
#include <Encoder.h>
 
#include <ros.h>
 
 
namespace diffbot
{
    struct JointState
    {
        double angular_position_;
        double angular_velocity_;
    };
 
 
    class Encoder
    {
    public:
        // Teensy Encoder class that is capable of reading rising and falling edges of two Hall effect signals.
        ::Encoder encoder;
 
        Encoder(ros::NodeHandle& nh, uint8_t pin1, uint8_t pin2, int encoder_resolution);
 
        int getRPM();
 
 
        double angularPosition();
 
        double angularVelocity();
 
 
        JointState jointState();
 
        double ticksToAngle(const int &ticks) const;
 
        inline int32_t read() { return encoder.read(); };
 
        inline void write(int32_t p) { encoder.write(p); };
 
        inline void resolution(int resolution) { encoder_resolution_ = resolution; };
 
        inline int resolution() { return encoder_resolution_; };
 
 
        JointState joint_state_;
 
    private:
        // ROS node handle, which provides the current time to compute the angular velocity from the current tick count
        ros::NodeHandle& nh_;
        // Number of tick counts for one full revolution of the wheel (not the motor shaft). Keep track of gear reduction ratio.
        int encoder_resolution_;
        // Previous time when the \ref getRPM or \ref angularVelocity method was called to calculated the delta update time.
        ros::Time prev_update_time_;
        // Previous encoder tick count when the \ref getRPM or \ref angularVelocity method was called to calculated the delta tick count.
        long prev_encoder_ticks_;
    };
}
 
#endif // DIFFBOT_ENCODER_H