ECE 2035
Dependents: ECE2035_FroggerGame_SUM2015 ECE2035_FroggerGame_SUM20151241 ECE2035_FroggerGame_SUM2015 rpg_game_shell ... more
Diff: MMA8452.h
- Revision:
- 0:53030e47347a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MMA8452.h Sun Jul 05 16:35:08 2015 +0000 @@ -0,0 +1,343 @@ +#pragma once + +// Authors: Ashley Mills, Nicholas Herriot +/* Copyright (c) 2013 Vodafone, MIT License + * + * 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. + */ + +// the SparkFun breakout board defaults to 1, set to 0 if SA0 jumper on the bottom of the board is set +// see the Table 10. I2C Device Address Sequence in Freescale MMA8452Q pdf + +#include "mbed.h" + +#define MMA8452_DEBUG 1 + +// More info on MCU Master address can be found on section 5.10.1 of http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MMA8452Q +#define SA0 1 +#if SA0 + #define MMA8452_ADDRESS 0x3A // 0x1D<<1 // SA0 is high, 0x1C if low - +#else + #define MMA8452_ADDRESS 0x38 // 0x1C<<1 +#endif + +// Register descriptions found in section 6 of pdf +#define MMA8452_STATUS 0x00 // Type 'read' : Status of the data registers +#define MMA8452_OUT_X_MSB 0x01 // Type 'read' : x axis - MSB of 2 byte sample +#define MMA8452_OUT_X_LSB 0x02 // Type 'read' : x axis - LSB of 2 byte sample +#define MMA8452_OUT_Y_MSB 0x03 // Type 'read' : y axis - MSB of 2 byte sample +#define MMA8452_OUT_Y_LSB 0x04 // Type 'read' : y axis - LSB of 2 byte sample +#define MMA8452_OUT_Z_MSB 0x05 // Type 'read' : z axis - MSB of 2 byte sample +#define MMA8452_OUT_Z_LSB 0x06 // Type 'read' : z axis - LSB of 2 byte sample + +// register definitions +#define MMA8452_XYZ_DATA_CFG 0x0E + +#define MMA8452_SYSMOD 0x0B // Type 'read' : This tells you if device is active, sleep or standy 0x00=STANDBY 0x01=WAKE 0x02=SLEEP +#define MMA8452_WHO_AM_I 0x0D // Type 'read' : This should return the device id of 0x2A + +#define MMA8452_PL_STATUS 0x10 // Type 'read' : This shows portrait landscape mode orientation +#define MMA8452_PL_CFG 0x11 // Type 'read/write' : This allows portrait landscape configuration +#define MMA8452_PL_COUNT 0x12 // Type 'read' : This is the portraint landscape debounce counter +#define MMA8452_PL_BF_ZCOMP 0x13 // Type 'read' : +#define MMA8452_PL_THS_REG 0x14 // Type 'read' : + +#define MMA8452_FF_MT_CFG 0X15 // Type 'read/write' : Freefaul motion functional block configuration +#define MMA8452_FF_MT_SRC 0X16 // Type 'read' : Freefaul motion event source register +#define MMA8452_FF_MT_THS 0X17 // Type 'read' : Freefaul motion threshold register +#define MMA8452_FF_COUNT 0X18 // Type 'read' : Freefaul motion debouce counter + +#define MMA8452_ASLP_COUNT 0x29 // Type 'read/write' : Counter settings for auto sleep +#define MMA8452_CTRL_REG_1 0x2A // Type 'read/write' : +#define MMA8452_CTRL_REG_2 0x2B // Type 'read/write' : +#define MMA8452_CTRL_REG_3 0x2C // Type 'read/write' : +#define MMA8452_CTRL_REG_4 0x2D // Type 'read/write' : +#define MMA8452_CTRL_REG_5 0x2E // Type 'read/write' : + +// Defined in table 13 of the Freescale PDF +/// xxx these all need to have better names +#define STANDBY 0x00 // State value returned after a SYSMOD request, it can be in state STANDBY, WAKE or SLEEP +#define WAKE 0x01 // State value returned after a SYSMOD request, it can be in state STANDBY, WAKE or SLEEP +#define SLEEP 0x02 // State value returned after a SYSMOD request, it can be in state STANDBY, WAKE or SLEEP +#define ACTIVE 0x01 // Stage value returned and set in Control Register 1, it can be STANDBY=00, or ACTIVE=01 + +#define TILT_STATUS 0x03 // Tilt Status (Read only) +#define SRST_STATUS 0x04 // Sample Rate Status Register (Read only) +#define SPCNT_STATUS 0x05 // Sleep Count Register (Read/Write) +#define INTSU_STATUS 0x06 // Interrupt Setup Register +#define MODE_STATUS 0x07 // Mode Register (Read/Write) +#define SR_STATUS 0x08 // Auto-Wake and Active Mode Portrait/Landscape Samples per Seconds Register (Read/Write) +#define PDET_STATUS 0x09 // Tap/Pulse Detection Register (Read/Write) +#define PD_STATUS 0xA // Tap/Pulse Debounce Count Register (Read/Write) + +// masks for enabling/disabling standby +#define MMA8452_ACTIVE_MASK 0x01 +#define MMA8452_STANDBY_MASK 0xFE + +// mask for dynamic range reading and writing +#define MMA8452_DYNAMIC_RANGE_MASK 0xFC + +// mask and shift for data rate reading and writing +#define MMA8452_DATA_RATE_MASK 0xC7 +#define MMA8452_DATA_RATE_MASK_SHIFT 0x03 + +// mask and shift for general reading and writing +#define MMA8452_WRITE_MASK 0xFE +#define MMA8452_READ_MASK 0x01 + +// mask and shift for bit depth reading and writing +#define MMA8452_BIT_DEPTH_MASK 0xFD +#define MMA8452_BIT_DEPTH_MASK_SHIFT 0x01 + +// status masks and shifts +#define MMA8452_STATUS_ZYXDR_MASK 0x08 +#define MMA8452_STATUS_ZDR_MASK 0x04 +#define MMA8452_STATUS_YDR_MASK 0x02 +#define MMA8452_STATUS_XDR_MASK 0x01 + +/** + * Wrapper for the MMA8452 I2C driven accelerometer. + */ +class MMA8452 { + + public: + + enum DynamicRange { + DYNAMIC_RANGE_2G=0x00, + DYNAMIC_RANGE_4G, + DYNAMIC_RANGE_8G, + DYNAMIC_RANGE_UNKNOWN + }; + + enum BitDepth { + BIT_DEPTH_12=0x00, + BIT_DEPTH_8, // 1 sets fast read mode, hence the inversion + BIT_DEPTH_UNKNOWN + }; + + enum DataRateHz { + RATE_800=0x00, + RATE_400, + RATE_200, + RATE_100, + RATE_50, + RATE_12_5, + RATE_6_25, + RATE_1_563, + RATE_UNKNOWN + }; + + /** + * Create an accelerometer object connected to the specified I2C pins. + * + * @param sda I2C data port + * @param scl I2C clock port + * @param frequency + * + */ + MMA8452(PinName sda, PinName scl, int frequency); + + /// Destructor + ~MMA8452(); + + /** + * Puts the MMA8452 in active mode. + * @return 0 on success, 1 on failure. + */ + int activate(); + + /** + * Puts the MMA8452 in standby. + * @return 0 on success, 1 on failure. + */ + int standby(); + + /** + * Read the device ID from the accelerometer (should be 0x2a) + * + * @param dst pointer to store the ID + * @return 0 on success, 1 on failure. + */ + int getDeviceID(char* dst); + + /** + * Read the MMA8452 status register. + * + * @param dst pointer to store the register value. + * @ return 0 on success, 1 on failure. + */ + int getStatus(char* dst); + + /** + * Read the raw x, y, an z registers of the MMA8452 in one operation. + * All three registers are read sequentially and stored in the provided buffer. + * The stored values are signed 2's complement left-aligned 12 or 8 bit integers. + * + * @param dst The destination buffer. Note that this needs to be 3 bytes for + * BIT_DEPTH_8 and 6 bytes for BIT_DEPTH_12. It is upto the caller to ensure this. + * @return 0 for success, and 1 for failure + * @sa setBitDepth + */ + int readXYZRaw(char *dst); + + /// Read the raw x register into the provided buffer. @sa readXYZRaw + int readXRaw(char *dst); + /// Read the raw y register into the provided buffer. @sa readXYZRaw + int readYRaw(char *dst); + /// Read the raw z register into the provided buffer. @sa readXYZRaw + int readZRaw(char *dst); + + /** + * Read the x, y, and z signed counts of the MMA8452 axes. + * + * Count resolution is either 8 bits or 12 bits, and the range is either +-2G, +-4G, or +-8G + * depending on settings. The number of counts per G are 1024, 512, 256 for 2,4, and 8 G + * respectively at 12 bit resolution and 64, 32, 16 for 2, 4, and 8 G respectively at + * 8 bit resolution. + * + * This function queries the MMA8452 and returns the signed counts for each axes. + * + * @param x Pointer to integer to store x count + * @param y Pointer to integer to store y count + * @param z Pointer to integer to store z count + * @return 0 on success, 1 on failure. + */ + int readXYZCounts(int *x, int *y, int *z); + + /// Read the x axes signed count. @sa readXYZCounts + int readXCount(int *x); + /// Read the y axes signed count. @sa readXYZCounts + int readYCount(int *y); + /// Read the z axes signed count. @sa readXYZCounts + int readZCount(int *z); + + /** + * Read the x, y, and z accelerations measured in G. + * + * The measurement resolution is controlled via setBitDepth which can + * be 8 or 12, and by setDynamicRange, which can be +-2G, +-4G, or +-8G. + * + * @param x A pointer to the double to store the x acceleration in. + * @param y A pointer to the double to store the y acceleration in. + * @param z A pointer to the double to store the z acceleration in. + * + * @return 0 on success, 1 on failure. + */ + int readXYZGravity(double *x, double *y, double *z); + + /// Read the x gravity in G into the provided double pointer. @sa readXYZGravity + int readXGravity(double *x); + /// Read the y gravity in G into the provided double pointer. @sa readXYZGravity + int readYGravity(double *y); + /// Read the z gravity in G into the provided double pointer. @sa readXYZGravity + int readZGravity(double *z); + + /// Returns 1 if data has been internally sampled (is available) for all axes since last read, 0 otherwise. + int isXYZReady(); + /// Returns 1 if data has been internally sampled (is available) for the x-axis since last read, 0 otherwise. + int isXReady(); + /// Returns 1 if data has been internally sampled (is available) for the y-axis since last read, 0 otherwise. + int isYReady(); + /// Returns 1 if data has been internally sampled (is available) for the z-axis since last read, 0 otherwise. + int isZReady(); + + /** + * Reads a single byte from the specified MMA8452 register. + * + * @param addr The internal register address. + * @param dst The destination buffer address. + * @return 1 on success, 0 on failure. + */ + int readRegister(char addr, char *dst); + + /** + * Reads n bytes from the specified MMA8452 register. + * + * @param addr The internal register address. + * @param dst The destination buffer address. + * @param nbytes The number of bytes to read. + * @return 1 on success, 0 on failure. + */ + int readRegister(char addr, char *dst, int nbytes); + + /** + * Write to the specified MMA8452 register. + * + * @param addr The internal register address + * @param data Data byte to write + */ + int writeRegister(char addr, char data); + + /** + * Write a data buffer to the specified MMA8452 register. + * + * @param addr The internal register address + * @param data Pointer to data buffer to write + * @param nbytes The length of the data buffer to write + */ + int writeRegister(char addr, char *data, int nbytes); + + int setDynamicRange(DynamicRange range, int toggleActivation=1); + int setBitDepth(BitDepth depth, int toggleActivation=1); + int setDataRate(DataRateHz dataRate, int toggleActivation=1); + + DynamicRange getDynamicRange(); + DataRateHz getDataRate(); + BitDepth getBitDepth(); + + #ifdef MMA8452_DEBUG + void debugRegister(char reg); + #endif + + private: + /** + * Reads the specified register, applies the mask with logical AND, logical ORs the value + * and writes back the result to the register. If toggleActivation is set to true then the + * device is put in standby before the operation, and activated at the end. + * Setting it to false is useful for setting options on a device that you want to keep in + * standby. + */ + int maskAndApplyRegister(char reg, char mask, char value, int toggleActivation); + + /// Reads the specified register, applies the mask with logical AND, and writes the result back. + int logicalANDRegister(char addr, char mask); + /// Reads the specified register, applies the mask with logical OR, and writes the result back. + int logicalORRegister(char addr, char mask); + /// Reads the specified register, applies the mask with logical XOR, and writes the result back. + int logicalXORRegister(char addr, char mask); + + /// Converts the 12-bit two's complement number in buf to a signed integer. Returns the integer. + int twelveBitToSigned(char *buf); + /// Converts the 8-bit two's complement number in buf to a signed integer. Returns the integer. + int eightBitToSigned(char *buf); + + /// Converts a count to a gravity using the supplied countsPerG. Returns the gravity. + double convertCountToGravity(int count, int countsPerG); + + /// Reads the register at addr, applies the mask with logical AND, and returns the result. + char getMaskedRegister(int addr, char mask); + + /// Get the counts per G for the current settings of bit depth and dynamic range. + int getCountsPerG(); + + I2C _i2c; + int _frequency; + int _readAddress; + int _writeAddress; + + BitDepth _bitDepth; + DynamicRange _dynamicRange; +}; \ No newline at end of file