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MMA8452.h
- Committer:
- ashleymills
- Date:
- 2014-03-07
- Revision:
- 21:a92a632a0cc7
- Parent:
- 20:d55e9d7eb17e
- Child:
- 22:0d00605bf830
File content as of revision 21:a92a632a0cc7:
#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; };