GY521.h

#pragma once
//
//    FILE: GY521.h
//  AUTHOR: Rob Tillaart
// VERSION: 0.3.6
// PURPOSE: Arduino library for I2C GY521 accelerometer-gyroscope sensor
//     URL: https://github.com/RobTillaart/GY521
//
// HISTORY:
// see GY521.cpp file
//


#include "Arduino.h"
#include "Wire.h"


#define GY521_LIB_VERSION           (F("0.3.6"))


#ifndef GY521_THROTTLE_TIME
#define GY521_THROTTLE_TIME         10   // milliseconds
#endif


// ERROR CODES
#define GY521_OK                     0
#define GY521_THROTTLED              1
#define GY521_ERROR_READ            -1
#define GY521_ERROR_WRITE           -2
#define GY521_ERROR_NOT_CONNECTED   -3


class GY521
{
public:
  GY521(uint8_t address = 0x69, TwoWire *wire = &Wire); // 0x68 or 0x69


#if defined (ESP8266) || defined(ESP32)
  bool     begin(uint8_t sda, uint8_t scl);
#endif
  bool     begin();
  bool     isConnected();
  void     reset();


  bool     wakeup();
  // throttle to force delay between reads.
  void     setThrottle(bool throttle = true) { _throttle = throttle; };
  bool     getThrottle()                     { return _throttle; };
  // 0..65535 (max milliseconds == roughly 1 minute.
  void     setThrottleTime(uint16_t ti )     { _throttleTime = ti; };
  uint16_t getThrottleTime()                 { return _throttleTime; };


  // returns GY521_OK or one of the error codes above.
  int16_t  read();

  // SET BEFORE READ
  // as = 0,1,2,3 ==> 2g 4g 8g 16g
  bool     setAccelSensitivity(uint8_t as);
  uint8_t  getAccelSensitivity();          // returns 0,1,2,3
  // gs = 0,1,2,3  ==>  250, 500, 1000, 2000 degrees/second
  bool     setGyroSensitivity(uint8_t gs);
  uint8_t  getGyroSensitivity();           // returns 0,1,2,3

  // CALL AFTER READ
  float    getAccelX()   { return _ax; };
  float    getAccelY()   { return _ay; };
  float    getAccelZ()   { return _az; };
  float    getAngleX()   { return _aax; };
  float    getAngleY()   { return _aay; };
  float    getAngleZ()   { return _aaz; };
  float    getTemperature() { return _temperature; };
  float    getGyroX()    { return _gx; };
  float    getGyroY()    { return _gy; };
  float    getGyroZ()    { return _gz; };
  float    getPitch()    { return _pitch; };
  float    getRoll()     { return _roll; };
  float    getYaw()      { return _yaw; };


  // last time sensor is actually read.
  uint32_t lastTime()    { return _lastTime; };


  // generic worker to get access to all functionality
  uint8_t  setRegister(uint8_t reg, uint8_t value);
  uint8_t  getRegister(uint8_t reg);


  // get last error and reset error to OK.
  int16_t  getError()    { return _error; _error = GY521_OK; };


  // calibration errors
  float    axe = 0, aye = 0, aze = 0;  // accelerometer errors
  float    gxe = 0, gye = 0, gze = 0;  // gyro errors


private:
  uint8_t  _address;                // I2C address
  bool     _throttle = true;        // to prevent reading too fast
  uint16_t _throttleTime = GY521_THROTTLE_TIME;
  uint32_t _lastTime = 0;           // to measure duration for math & throttle
  uint32_t _lastMicros = 0;         // to measure duration for math & throttle
  int16_t  _error = GY521_OK;       // initially everything is OK

  uint8_t  _afs = 0;                // sensitivity factor
  float    _raw2g = 1.0/16384.0;    // raw data to gravity g's
  float    _ax, _ay, _az;           // accelerometer raw
  float    _aax, _aay, _aaz;        // accelerometer processed

  uint8_t  _gfs = 0;
  float    _raw2dps = 1.0/131.0;
  float    _gx, _gy, _gz;           // gyro raw
  float    _gax, _gay, _gaz;        // gyro processed.
  float    _pitch, _roll, _yaw;     // used by user

  float    _temperature = 0;

  // to read register of 2 bytes.
  int16_t  _WireRead2();

  TwoWire*  _wire;
};


// -- END OF FILE --