// MMA7455 Accelerometer
// ---------------------
//
// By arduino.cc user "Krodal".
// May 2012
// Open Source / Public Domain
//
// Fixes to union and type conversions by Arduino.cc user "Afroviking"
// August 2014
//
// Using Arduino 1.0.1
// It will not work with an older version, since Wire.endTransmission()
// uses a parameter to hold or release the I2C bus.
//
// Documentation:
// - The Freescale MMA7455L datasheet
// - The AN3468 Application Note (programming).
// - The AN3728 Application Note (calibrating offset).
//
// The MMA7455 can be used by writing and reading a single byte,
// but it is also capable to read and write multiple bytes.
//
// The accuracy is 10-bits.
//
#include
// Register names according to the datasheet.
// Register 0x1C is sometimes called 'PW', and sometimes 'PD'.
// The two reserved registers can not be used.
#define MMA7455_XOUTL 0x00 // Read only, Output Value X LSB
#define MMA7455_XOUTH 0x01 // Read only, Output Value X MSB
#define MMA7455_YOUTL 0x02 // Read only, Output Value Y LSB
#define MMA7455_YOUTH 0x03 // Read only, Output Value Y MSB
#define MMA7455_ZOUTL 0x04 // Read only, Output Value Z LSB
#define MMA7455_ZOUTH 0x05 // Read only, Output Value Z MSB
#define MMA7455_XOUT8 0x06 // Read only, Output Value X 8 bits
#define MMA7455_YOUT8 0x07 // Read only, Output Value Y 8 bits
#define MMA7455_ZOUT8 0x08 // Read only, Output Value Z 8 bits
#define MMA7455_STATUS 0x09 // Read only, Status Register
#define MMA7455_DETSRC 0x0A // Read only, Detection Source Register
#define MMA7455_TOUT 0x0B // Temperature Output Value (Optional)
#define MMA7455_RESERVED1 0x0C // Reserved
#define MMA7455_I2CAD 0x0D // Read/Write, I2C Device Address
#define MMA7455_USRINF 0x0E // Read only, User Information (Optional)
#define MMA7455_WHOAMI 0x0F // Read only, "Who am I" value (Optional)
#define MMA7455_XOFFL 0x10 // Read/Write, Offset Drift X LSB
#define MMA7455_XOFFH 0x11 // Read/Write, Offset Drift X MSB
#define MMA7455_YOFFL 0x12 // Read/Write, Offset Drift Y LSB
#define MMA7455_YOFFH 0x13 // Read/Write, Offset Drift Y MSB
#define MMA7455_ZOFFL 0x14 // Read/Write, Offset Drift Z LSB
#define MMA7455_ZOFFH 0x15 // Read/Write, Offset Drift Z MSB
#define MMA7455_MCTL 0x16 // Read/Write, Mode Control Register
#define MMA7455_INTRST 0x17 // Read/Write, Interrupt Latch Reset
#define MMA7455_CTL1 0x18 // Read/Write, Control 1 Register
#define MMA7455_CTL2 0x19 // Read/Write, Control 2 Register
#define MMA7455_LDTH 0x1A // Read/Write, Level Detection Threshold Limit Value
#define MMA7455_PDTH 0x1B // Read/Write, Pulse Detection Threshold Limit Value
#define MMA7455_PD 0x1C // Read/Write, Pulse Duration Value
#define MMA7455_LT 0x1D // Read/Write, Latency Time Value (between pulses)
#define MMA7455_TW 0x1E // Read/Write, Time Window for Second Pulse Value
#define MMA7455_RESERVED2 0x1F // Reserved
// Defines for the bits, to be able to change
// between bit number and binary definition.
// By using the bit number, programming the MMA7455
// is like programming an AVR microcontroller.
// But instead of using "(1<