as5050.h

//////////////////////////////////////////////////////////////////////////
//                     libAS5050
// This library aims to provide easy and convenient
// communication with the AS5050 magnetic rotary encoder IC.
//////////////////////////////////////////////////////////////////////////
// Written and maintained by Dan Sheadel (tekdemo@gmail.com)
// Code available at http://github.com/tekdemo 
//////////////////////////////////////////////////////////////////////////
//
// This program is free software; you can redistribute it 
// and/or modify it under the terms of the GNU General    
// Public License as published by the Free Software       
// Foundation; either version 2 of the License, or        
// (at your option) any later version.                    
//                                                        
// This program is distributed in the hope that it will   
// be useful, but WITHOUT ANY WARRANTY; without even the  
// implied warranty of MERCHANTABILITY or FITNESS FOR A   
// PARTICULAR PURPOSE.  See the GNU General Public        
// License for more details.                              
//                                                        
// You should have received a copy of the GNU General    
// Public License along with this program; if not, write 
// to the Free Software Foundation, Inc.,                
// 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
//                                                        
// Licence can be viewed at                               
// http://www.fsf.org/licenses/gpl.txt                    
//
// Please maintain this license information along with authorship
// and copyright notices in any redistribution of this code
//
//////////////////////////////////////////////////////////////////////////

#ifndef _AS5050_H_INCLUDED
#define _AS5050_H_INCLUDED

//Must include standard libs!
#include "Arduino.h"
#include <SPI.h>


//Various library options for tweaking behaviors
#ifndef AS5050_AUTO_ERROR_HANDLING
  #define AS5050_AUTO_ERROR_HANDLING 1
#endif

#ifndef AS5050_RESET_ON_ERRORS
  #define AS5050_RESET_ON_ERRORS 1
#endif

//Command values for reading and writing
#define AS_WRITE  (0x0000)
#define AS_READ   (0x8000)


/*AS5050 Register values
Shifted 1 to make room for parity bit
OR with AS_READ/AS_WRITE before sending command
*/
#define REG_POWER_ON_RESET (0x3F22)
#define REG_SOFTWARE_RESET (0x3C00) 
#define REG_MASTER_RESET   (0x33A5)
#define REG_CLEAR_ERROR    (0x3380)/*Read to reset errors*/
#define REG_NOP            (0x0000)
#define REG_GAIN_CONTROL   (0x3FF8)
#define REG_ANGLE          (0x3FFF)
#define REG_ERROR_STATUS   (0x33A5)

//Data packets when writing the software Reset regarding clearing SPI or not
#define DATA_SWRESET_SPI    (0x11)  
#define DATA_SWRESET_NO_SPI (0x00)

//Ways to check the responses from the AS5050 when
#define RES_PARITY         (0x1)
#define RES_ERROR_FLAG     (0x2)
#define RES_ALARM_HIGH     (0x8000)   /*Magnetic Field too high*/
#define RES_ALARM_LOW      (0x4000)   /*Magnetic Field too low*/
#define RES_ERROR          (RES_PARITY|RES_ERROR_FLAG)  //standard error frame
//error from reading the angle
#define RES_ERROR_ANGLE    (RES_PARITY| RES_ERROR_FLAG|RES_ALARM_HIGH|RES_ALARM_LOW) 

//Error Status Register
#define ERR_PARITY    (1<<13)
#define ERR_CLKMON    (1<<12)
#define ERR_ADDMON    (1<<11)
//#define RES_ERR_RESERVED3  (1<<10)
#define ERR_WOW       (1<<9)
#define ERR_MODE      (1<<8)	
//#define RES_ERR_RESERVED6  (1<<7)
//#define RES_ERR_RESERVED7  (1<<6)
#define ERR_DACOV     (1<<5)	// DAC overflow
#define ERR_DSPOV     (1<<4)    //DSP PRocessor overflow
#define ERR_RANERR    (1<<3)	//Range error
#define ERR_DSPALO    (1<<2)	//DSP Alarm low
#define ERR_DSPAHI    (1<<1)	//DSP Alarm High
//#define RES_ERR_RESERVED13  (1<<0)

//Set various limits on some values
#define AS5050_ANGULAR_RESOLUTION 1024
#define AS5050_MAX_GAIN 31 //5 bits of storage
#define AS5050_MIN_GAIN 0


//use unions to quickly access data values
union spi_data{
  unsigned int value;
  struct{
    byte lsb; //lowest byte in struct
    byte msb; //next up
  } bytes;
};



class AS5050{
  public:
    AS5050(byte pin, byte spi_speed);
        unsigned int send(unsigned int);

    unsigned int read(unsigned int);
    unsigned int write(unsigned int,unsigned int);
    int angle();
    unsigned int handleErrors();
    float angleDegrees();
    float angleRad();
    float wrapAngle(float);
    struct error_struct{
      unsigned int transaction;      //holds the error data from angular reads
      unsigned int status;           //holds the AS5050 error data from other sources
    }error;
    
    //Store the current gain value, so it can be recorded
    byte gain;
    
    //Keep track of how many full rotations we've gone through
    int rotations;


    private:
        byte _pin;
        int _last_angle;
};

#endif