//

//Iain Frew - 8/30/17
//
//IDE is Visual Studio using Vmicro add-in for Arduino development
//
//This is a port of Hari Nair project to esp32 and using the DMP functionaility of
//the 9250 IMU.
//
//The majortity of this code was some great work by Jeff Rowberg for the
//mpu6050 library and the i2cdevlib interface, and Hari Nair for the Vario design.
//The calibration came from  Luis Ródenas.

//I integrated Jeff's MPU6050 library to take advantage of the 6050 dmp processing which works fine
//on esp8266 but a bit tempremental on esp32 as there are some issues with timing using Jeff's library
//and the I2C bus. You need to be able to read in chunks using a buffer size of about 16.
//So for my chips and setup I played around with the buffer_length set in i2cdevlib.cpp and eventually chose 16.
//Anything larger tends to screw up the data being read. Also found that the readings are noisy when
//reading from the DMP at 200Hz as jeff found. So reduced ODR to 100Hz and modified the code accordingly to take
//that into account.

//I have a define to enable/disable DMP processing rather than calculate manually the rotations that Hari used.
//Seems to be accurate and reduces the loop elapsed time by a factor of 3.

//Correct calibration I have found is key but on two gy-86, values of 1700 and 1200 for kfzVariance an kfazVariance
//seem to work best. Configuration in the config.h file of zero theshold 20 and climb threshold 20
//also produce good results.
//
//To build, you only need the esp32 core library installed as this sketch uses the preference, wire and wifi libraries
//
//
//This code uses the gy-86 IMU and the reference system is different than the CJMCU-117 that Hari used. If you use the
//cjmcu-117 module then just turn the board upside down and you get the same reults as the gy-86 which assumes the chips are up facing you
//when used.

// gy-86 interface
// 3.3V  3.3v
// GND  GND
// SCL  GPIO21
// SDA  GPIO22
// INT  GPIO12
// audio GPIO13
// calibration button GPIO15

Author: ifrew

I2Cdev.cpp

@@ -0,0 +1,278 @@
+// I2Cdev library collection - Main I2C device class header file
+// Abstracts bit and byte I2C R/W functions into a convenient class
+// 2013-06-05 by Jeff Rowberg <[email protected]>
+//
+// Changelog:
+//      2015-10-30 - simondlevy : support i2c_t3 for Teensy3.1
+//      2013-05-06 - add Francesco Ferrara's Fastwire v0.24 implementation with small modifications
+//      2013-05-05 - fix issue with writing bit values to words (Sasquatch/Farzanegan)
+//      2012-06-09 - fix major issue with reading > 32 bytes at a time with Arduino Wire
+//                 - add compiler warnings when using outdated or IDE or limited I2Cdev implementation
+//      2011-11-01 - fix write*Bits mask calculation (thanks sasquatch @ Arduino forums)
+//      2011-10-03 - added automatic Arduino version detection for ease of use
+//      2011-10-02 - added Gene Knight's NBWire TwoWire class implementation with small modifications
+//      2011-08-31 - added support for Arduino 1.0 Wire library (methods are different from 0.x)
+//      2011-08-03 - added optional timeout parameter to read* methods to easily change from default
+//      2011-08-02 - added support for 16-bit registers
+//                 - fixed incorrect Doxygen comments on some methods
+//                 - added timeout value for read operations (thanks mem @ Arduino forums)
+//      2011-07-30 - changed read/write function structures to return success or byte counts
+//                 - made all methods static for multi-device memory savings
+//      2011-07-28 - initial release
+
+/* ============================================
+I2Cdev device library code is placed under the MIT license
+Copyright (c) 2013 Jeff Rowberg
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+===============================================
+*/
+
+#ifndef _I2CDEV_H_
+#define _I2CDEV_H_
+
+// -----------------------------------------------------------------------------
+// I2C interface implementation setting
+// -----------------------------------------------------------------------------
+#ifndef I2CDEV_IMPLEMENTATION
+#define I2CDEV_IMPLEMENTATION       I2CDEV_ARDUINO_WIRE
+//#define I2CDEV_IMPLEMENTATION       I2CDEV_BUILTIN_FASTWIRE
+#endif // I2CDEV_IMPLEMENTATION
+
+// comment this out if you are using a non-optimal IDE/implementation setting
+// but want the compiler to shut up about it
+#define I2CDEV_IMPLEMENTATION_WARNINGS
+
+// -----------------------------------------------------------------------------
+// I2C interface implementation options
+// -----------------------------------------------------------------------------
+#define I2CDEV_ARDUINO_WIRE         1 // Wire object from Arduino
+#define I2CDEV_BUILTIN_NBWIRE       2 // Tweaked Wire object from Gene Knight's NBWire project
+                                      // ^^^ NBWire implementation is still buggy w/some interrupts!
+#define I2CDEV_BUILTIN_FASTWIRE     3 // FastWire object from Francesco Ferrara's project
+#define I2CDEV_I2CMASTER_LIBRARY    4 // I2C object from DSSCircuits I2C-Master Library at https://github.com/DSSCircuits/I2C-Master-Library
+
+// -----------------------------------------------------------------------------
+// Arduino-style "Serial.print" debug constant (uncomment to enable)
+// -----------------------------------------------------------------------------
+//#define I2CDEV_SERIAL_DEBUG
+
+#ifdef ARDUINO
+    #if ARDUINO < 100
+        #include "WProgram.h"
+    #else
+        #include "Arduino.h"
+    #endif
+    #if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
+        #include <Wire.h>
+    #endif
+    #if I2CDEV_IMPLEMENTATION == I2CDEV_I2CMASTER_LIBRARY
+        #include <I2C.h>
+    #endif
+#endif
+
+#ifdef SPARK
+    #include <spark_wiring_i2c.h>
+    #define ARDUINO 101
+#endif
+
+
+// 1000ms default read timeout (modify with "I2Cdev::readTimeout = [ms];")
+#define I2CDEV_DEFAULT_READ_TIMEOUT     1000
+
+class I2Cdev {
+    public:
+        I2Cdev();
+
+        static int8_t readBit(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint8_t *data, uint16_t timeout=I2Cdev::readTimeout);
+        static int8_t readBitW(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint16_t *data, uint16_t timeout=I2Cdev::readTimeout);
+        static int8_t readBits(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint8_t *data, uint16_t timeout=I2Cdev::readTimeout);
+        static int8_t readBitsW(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint16_t *data, uint16_t timeout=I2Cdev::readTimeout);
+        static int8_t readByte(uint8_t devAddr, uint8_t regAddr, uint8_t *data, uint16_t timeout=I2Cdev::readTimeout);
+        static int8_t readWord(uint8_t devAddr, uint8_t regAddr, uint16_t *data, uint16_t timeout=I2Cdev::readTimeout);
+        static int8_t readBytes(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint8_t *data, uint16_t timeout=I2Cdev::readTimeout);
+        static int8_t readWords(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint16_t *data, uint16_t timeout=I2Cdev::readTimeout);
+
+        static bool writeBit(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint8_t data);
+        static bool writeBitW(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint16_t data);
+        static bool writeBits(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint8_t data);
+        static bool writeBitsW(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint16_t data);
+        static bool writeByte(uint8_t devAddr, uint8_t regAddr, uint8_t data);
+        static bool writeWord(uint8_t devAddr, uint8_t regAddr, uint16_t data);
+        static bool writeBytes(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint8_t *data);
+        static bool writeWords(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint16_t *data);
+
+        static uint16_t readTimeout;
+};
+
+#if I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE
+    //////////////////////
+    // FastWire 0.24
+    // This is a library to help faster programs to read I2C devices.
+    // Copyright(C) 2012
+    // Francesco Ferrara
+    //////////////////////
+
+    /* Master */
+    #define TW_START                0x08
+    #define TW_REP_START            0x10
+
+    /* Master Transmitter */
+    #define TW_MT_SLA_ACK           0x18
+    #define TW_MT_SLA_NACK          0x20
+    #define TW_MT_DATA_ACK          0x28
+    #define TW_MT_DATA_NACK         0x30
+    #define TW_MT_ARB_LOST          0x38
+
+    /* Master Receiver */
+    #define TW_MR_ARB_LOST          0x38
+    #define TW_MR_SLA_ACK           0x40
+    #define TW_MR_SLA_NACK          0x48
+    #define TW_MR_DATA_ACK          0x50
+    #define TW_MR_DATA_NACK         0x58
+
+    #define TW_OK                   0
+    #define TW_ERROR                1
+
+    class Fastwire {
+        private:
+            static boolean waitInt();
+
+        public:
+            static void setup(int khz, boolean pullup);
+            static byte beginTransmission(byte device);
+            static byte write(byte value);
+            static byte writeBuf(byte device, byte address, byte *data, byte num);
+            static byte readBuf(byte device, byte address, byte *data, byte num);
+            static void reset();
+            static byte stop();
+    };
+#endif
+
+#if I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_NBWIRE
+    // NBWire implementation based heavily on code by Gene Knight <[email protected]>
+    // Originally posted on the Arduino forum at http://arduino.cc/forum/index.php/topic,70705.0.html
+    // Originally offered to the i2cdevlib project at http://arduino.cc/forum/index.php/topic,68210.30.html
+
+    #define NBWIRE_BUFFER_LENGTH 32
+
+    class TwoWire {
+        private:
+            static uint8_t rxBuffer[];
+            static uint8_t rxBufferIndex;
+            static uint8_t rxBufferLength;
+
+            static uint8_t txAddress;
+            static uint8_t txBuffer[];
+            static uint8_t txBufferIndex;
+            static uint8_t txBufferLength;
+
+            // static uint8_t transmitting;
+            static void (*user_onRequest)(void);
+            static void (*user_onReceive)(int);
+            static void onRequestService(void);
+            static void onReceiveService(uint8_t*, int);
+
+        public:
+            TwoWire();
+            void begin();
+            void begin(uint8_t);
+            void begin(int);
+            void beginTransmission(uint8_t);
+            //void beginTransmission(int);
+            uint8_t endTransmission(uint16_t timeout=0);
+            void nbendTransmission(void (*function)(int)) ;
+            uint8_t requestFrom(uint8_t, int, uint16_t timeout=0);
+            //uint8_t requestFrom(int, int);
+            void nbrequestFrom(uint8_t, int, void (*function)(int));
+            void send(uint8_t);
+            void send(uint8_t*, uint8_t);
+            //void send(int);
+            void send(char*);
+            uint8_t available(void);
+            uint8_t receive(void);
+            void onReceive(void (*)(int));
+            void onRequest(void (*)(void));
+    };
+
+    #define TWI_READY   0
+    #define TWI_MRX     1
+    #define TWI_MTX     2
+    #define TWI_SRX     3
+    #define TWI_STX     4
+
+    #define TW_WRITE    0
+    #define TW_READ     1
+
+    #define TW_MT_SLA_NACK      0x20
+    #define TW_MT_DATA_NACK     0x30
+
+    #define CPU_FREQ            16000000L
+    #define TWI_FREQ            100000L
+    #define TWI_BUFFER_LENGTH   32
+
+    /* TWI Status is in TWSR, in the top 5 bits: TWS7 - TWS3 */
+
+    #define TW_STATUS_MASK              (_BV(TWS7)|_BV(TWS6)|_BV(TWS5)|_BV(TWS4)|_BV(TWS3))
+    #define TW_STATUS                   (TWSR & TW_STATUS_MASK)
+    #define TW_START                    0x08
+    #define TW_REP_START                0x10
+    #define TW_MT_SLA_ACK               0x18
+    #define TW_MT_SLA_NACK              0x20
+    #define TW_MT_DATA_ACK              0x28
+    #define TW_MT_DATA_NACK             0x30
+    #define TW_MT_ARB_LOST              0x38
+    #define TW_MR_ARB_LOST              0x38
+    #define TW_MR_SLA_ACK               0x40
+    #define TW_MR_SLA_NACK              0x48
+    #define TW_MR_DATA_ACK              0x50
+    #define TW_MR_DATA_NACK             0x58
+    #define TW_ST_SLA_ACK               0xA8
+    #define TW_ST_ARB_LOST_SLA_ACK      0xB0
+    #define TW_ST_DATA_ACK              0xB8
+    #define TW_ST_DATA_NACK             0xC0
+    #define TW_ST_LAST_DATA             0xC8
+    #define TW_SR_SLA_ACK               0x60
+    #define TW_SR_ARB_LOST_SLA_ACK      0x68
+    #define TW_SR_GCALL_ACK             0x70
+    #define TW_SR_ARB_LOST_GCALL_ACK    0x78
+    #define TW_SR_DATA_ACK              0x80
+    #define TW_SR_DATA_NACK             0x88
+    #define TW_SR_GCALL_DATA_ACK        0x90
+    #define TW_SR_GCALL_DATA_NACK       0x98
+    #define TW_SR_STOP                  0xA0
+    #define TW_NO_INFO                  0xF8
+    #define TW_BUS_ERROR                0x00
+
+    //#define _MMIO_BYTE(mem_addr) (*(volatile uint8_t *)(mem_addr))
+    //#define _SFR_BYTE(sfr) _MMIO_BYTE(_SFR_ADDR(sfr))
+
+    #ifndef sbi // set bit
+        #define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
+    #endif // sbi
+
+    #ifndef cbi // clear bit
+        #define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
+    #endif // cbi
+
+    extern TwoWire Wire;
+
+#endif // I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_NBWIRE
+
+#endif /* _I2CDEV_H_ */