Revision 0:9d1e3a344e4f, committed 2013-03-29

Comitter:

sam_grove

Date:

Fri Mar 29 21:51:11 2013 +0000

Commit message:

Work in progress

Changed in this revision

diff -r 000000000000 -r 9d1e3a344e4f MMA845x.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA845x.cpp	Fri Mar 29 21:51:11 2013 +0000
@@ -0,0 +1,174 @@
+/**
+ * @file    MMA845x.cpp
+ * @brief   Device driver - MMA845X 3-axis accelerometer IC
+ * @author  sam grove
+ * @version 1.0
+ * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8451Q.pdf
+ * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8452Q.pdf
+ * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8453Q.pdf
+ *
+ * Copyright (c) 2013
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include "MMA845x.h"
+ 
+MMA845x::MMA845x(I2C &i2c, InterruptIn &int1, InterruptIn &int2, MMA845x_SA0 const i2c_addr)
+{
+    _i2c =  &i2c;
+    _int1 = &int1;
+    _int2 = &int2;
+    
+    _i2c_addr = (0x1c << 2) | (i2c_addr << 0x1);
+ 
+    return;
+}
+
+void MMA845x::init(void) const
+{
+    uint8_t reg_val = 0;
+    
+    _i2c->frequency(400000);
+    
+    // Reset all registers to POR values
+    MMA845x::writeRegister(CTRL_REG2, 0xFF);        //REG 0x2B
+    do{
+        // wait for the reset bit to clear
+        reg_val = MMA845x::readRegister(CTRL_REG2) & 0x40;
+    }while(reg_val);
+    
+    // setup the registers that are common among modes
+    MMA845x::writeRegister(CTRL_REG1, 0xd8);        //REG 0x2A
+    MMA845x::writeRegister(CTRL_REG2, 0x00);        //REG 0x2B
+    MMA845x::writeRegister(CTRL_REG3, 0x00);        //REG 0x2C
+    
+    MMA845x::writeRegister(XYZ_DATA_CFG, 0x0);      //REG 0xE HPF / scale +/-2,4,8g
+    MMA845x::writeRegister(HP_FILTER_CUTOFF, 0x0);  //REG 0xF HPF settings
+    
+    return;
+}
+
+void MMA845x::enableDataReadyMode(void) const
+{
+    MMA845x::init();
+    MMA845x::writeRegister(SYSMOD, 0x1);        //REG 0x0B
+    MMA845x::writeRegister(INT_SOURCE, 0x1);    //REG 0x0C
+    // need to finish up these config registers..... 3/8/13
+    
+}
+
+void MMA845x::enableMotionMode(void) const{}
+void MMA845x::enablePulseMode(void) const{}
+
+void MMA845x::enableOrientationMode(void) const
+{
+    uint16_t who_am_i = MMA845x::readRegister(WHO_AM_I);
+    if(who_am_i != MMA8451)
+    {
+        error("%s %d: Feature not compatible with the connected device.\n", __FILE__, __LINE__);
+    }
+    
+    return;
+}
+
+void MMA845x::enableTransitMode(void) const{}
+void MMA845x::enableAutoSleepMode(void) const{}
+
+void MMA845x::enableFIFOMode(void) const
+{
+    uint16_t who_am_i = MMA845x::readRegister(WHO_AM_I);
+    if(who_am_i != MMA8451)
+    {
+        error("%s %d: Feature not compatible with the connected device.\n", __FILE__, __LINE__);
+    }
+    
+    //MMA845x::writeRegister(
+    
+    return;
+}
+
+uint16_t MMA845x::getX(void) const
+{
+    return _data._x;
+}
+    
+uint16_t MMA845x::getY(void) const
+{
+    return _data._y;
+}
+
+uint16_t MMA845x::getZ(void) const
+{
+    return _data._z;
+}
+    
+MMA845x_DATA MMA845x::getXYZ(void) const
+{
+    return _data;
+}
+
+void MMA845x::writeRegister(uint8_t const reg, uint8_t const data) const
+{
+    char buf[2] = {reg, data};
+    uint8_t result = 0;
+    
+    __disable_irq(); // Tickers and other timebase events can jack up the I2C bus for some deicse
+    result = _i2c->write(_i2c_addr, buf, 2);
+    __enable_irq();  // Just need to block during the transaction
+    
+    if(0 != result)
+    {
+        error("%s %d: I2c write failed\n", __FILE__, __LINE__);
+    }
+    
+    return;
+}
+
+uint8_t MMA845x::readRegister(uint8_t const reg) const
+{
+    uint8_t result = 1, data = 0;
+    
+    __disable_irq(); // Tickers and other timebase events can jack up the I2C bus
+    _i2c->start();
+    result &= _i2c->write(_i2c_addr);
+    result &= _i2c->write(reg);
+    // issue a repeated start...
+    _i2c->start();
+    result &= _i2c->write(_i2c_addr | 0x01);
+    // read with nak
+    data = _i2c->read(0);
+    _i2c->stop();
+    __enable_irq();  // Just need to block during the transaction
+    
+    if(1 != result)
+    {
+        error("%s %d: I2C read failed\n", __FILE__, __LINE__);
+    }
+    
+    return data;
+}
+
+void MMA845x::registerDump(void) const
+{
+    uint8_t reg_val = 0;
+    
+    for(int i=0; i<0x80; i++)
+    {
+        reg_val = MMA845x::readRegister(i);
+        printf("Reg 0x%02x: 0x%02x \n", i, reg_val);
+    }
+    
+    return;
+}
+

diff -r 000000000000 -r 9d1e3a344e4f MMA845x.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA845x.h	Fri Mar 29 21:51:11 2013 +0000
@@ -0,0 +1,221 @@
+/**
+ * @file    MMA845x.h
+ * @brief   Device driver - MMA845x 3-axis accelerometer IC
+ * @author  sam grove
+ * @version 1.0
+ * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8451Q.pdf
+ * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8452Q.pdf
+ * @see     http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8453Q.pdf
+ *
+ * Copyright (c) 2013
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#ifndef MMA845X_H
+#define MMA845X_H
+
+#include "mbed.h"
+
+/** Using the Sparkfun SEN-10955
+ *
+ * Example:
+ * @code
+ *  #include "mbed.h"
+ *  #include "MMA845x.h"
+ *
+
+ * 
+ *  int main() 
+ *  {
+
+ *  }
+ * @endcode
+ */
+
+
+/**
+ *  @class MMA845x_DATA
+ *  @brief API abstraction for the MMA845x 3-axis accelerometer IC data
+ */  
+class MMA845x_DATA
+{      
+public:
+    
+    volatile uint16_t _x;   /*!< volatile data variable */
+    volatile uint16_t _y;   /*!< volatile data variable */
+    volatile uint16_t _z;   /*!< volatile data variable */
+   
+    /** Create the MMA845x_DATA object initialized to the parameter (or 0 if none)
+     *  @param x - the init value of _x
+     *  @param y - the init value of _y
+     *  @param x - the init value of _z
+     */
+    MMA845x_DATA(uint16_t x = 0, uint16_t y = 0, uint16_t z = 0) : _x(x), _y(y), _z(z) {}
+    
+    /** Overloaded '=' operator to allow shorthand coding, assigning objects to one another
+     *  @param rhs - an object of the same type to assign ourself the same values of
+     *  @return this
+     */
+    MMA845x_DATA &operator= (MMA845x_DATA const &rhs)
+    {
+        _x = rhs._x;
+        _y = rhs._y;
+        _z = rhs._z;
+        
+        return *this;
+    }
+    
+    /** Overloaded '=' operator to allow shorthand coding, assigning objects to one another
+     *  @param val - Assign each data member (_x, _y, _z) this value
+     *  @return this
+     */
+    MMA845x_DATA &operator= (uint16_t const val)
+    {
+        _x = _y = _z = val;
+        
+        return *this;
+    }
+    
+    /** Overloaded '==' operator to allow shorthand coding, test objects to one another
+     *  @param rhs - the object to compare against
+     *  @return 1 if the data members are the same and 0 otherwise
+     */
+    bool operator== (MMA845x_DATA const &rhs) const
+    {
+        return ((_x == rhs._x)&&(_y == rhs._y)&&(_z == rhs._z)) ? 1 : 0;
+    }
+    
+};
+
+/**
+ *  @class MMA845x
+ *  @brief API abstraction for the MMA845x 3-axis accelerometer IC
+ */ 
+class MMA845x
+{  
+public:
+    
+    /**
+     *  @enum MMA845x_SA0
+     *  @brief Possible terminations for the ADDR pin
+     */ 
+    enum MMA845x_SA0
+    { 
+        SA0_VSS = 0, /*!< SA0 connected to VSS */
+        SA0_VDD      /*!< SA0 connected to VDD */
+    };
+    
+    /**
+     *  @enum MMA845x_WHO_AM_I
+     *  @brief Device ID's that this class is compatible with
+     */ 
+    enum MMA845x_WHO_AM_I
+    { 
+        MMA8451 = 0x1a, /*!< MMA8451 WHO_AM_I register content */
+        MMA8452 = 0x2a, /*!< MMA8452 WHO_AM_I register content */
+        MMA8453 = 0x3a, /*!< MMA8453 WHO_AM_I register content */
+    };
+    
+    /**
+     *  @enum MMA845x_REGISTER
+     *  @brief The device register map
+     */
+    enum MMA845x_REGISTER
+    {
+        STATUS = 0x0,
+        OUT_X_MSB, OUT_X_LSB, OUT_Y_MSB, OUT_Y_LSB, OUT_Z_MSB, OUT_Z_LSB,
+        
+        F_SETUP = 0x9, TRIG_CFG, // only available on the MMA8451 variant
+        
+        SYSMOD = 0xb,
+        INT_SOURCE, WHO_AM_I, XYZ_DATA_CFG, HP_FILTER_CUTOFF, PL_STATUS,
+        PL_CFG, PL_COUNT, PL_BF_ZCOMP, P_L_THS_REG, FF_MT_CFG, FF_MT_SRC,
+        FF_MT_THS, FF_MT_COUNT,
+        
+        TRANSIENT_CFG = 0x1d,
+        TRANSIENT_SRC, TRANSIENT_THS, TRANSIENT_COUNT, PULSE_CFG, PULSE_SRC,
+        PULSE_THSX, PULSE_THSY, PULSE_THSZ, PULSE_TMLT, PULSE_LTCY, PULSE_WIND,
+        ASLP_COUNT, CTRL_REG1, CTRL_REG2, CTRL_REG3, CTRL_REG4, CTRL_REG5,
+        OFF_X, OFF_Y, OFF_Z
+    };
+        
+    /** Create the MMA845x object
+     *  @param i2c - A defined I2C object
+     *  @param int1 - A defined InterruptIn object
+     *  @param int2 - A defined InterruptIn object
+     *  @param i2c_addr - Connection of the address line
+     */ 
+    MMA845x(I2C &i2c, InterruptIn &int1, InterruptIn &int2, MMA845x_SA0 const i2c_addr);
+    
+    /** Get the X data
+     *  @return The last valid reading from the accelerometer
+     */
+    uint16_t getX(void) const;
+    
+    /** Get the Y data
+     *  @return The last valid reading from the accelerometer
+     */
+    uint16_t getY(void) const;
+    
+    /** Get the Z data
+     *  @return The last valid reading from the accelerometer
+     */
+    uint16_t getZ(void) const;
+    
+    /** Get the XYZ data structure
+     *  @return The last valid reading from the accelerometer
+     */
+    MMA845x_DATA getXYZ(void) const;
+    
+    void enableDataReadyMode(void) const;
+    void enableMotionMode(void) const;
+    void enablePulseMode(void) const;
+    void enableOrientationMode(void) const;
+    void enableTransitMode(void) const;
+    void enableAutoSleepMode(void) const;
+    void enableFIFOMode(void) const;
+    
+    /** Put the MMA845x in the lowest possible power mode and suspend operation
+     */
+    void disable(void);
+    
+    /** Write to a register (exposed for debugging reasons)
+     *  Note: most writes are only valid in stop mode
+     *  @param reg - The register to be written
+     *  @param data - The data to be written
+     */
+    void writeRegister(uint8_t const reg, uint8_t const data) const;
+    
+    /** Read from a register (exposed for debugging reasons)
+     *  @param reg - The register to read from
+     *  @return The register contents
+     */
+    uint8_t readRegister(uint8_t const reg) const;
+    
+    /** print the register map and values to the console
+     */
+    void registerDump(void) const;
+    
+private:
+    
+    I2C         *_i2c;
+    InterruptIn *_int1;
+    InterruptIn *_int2;
+    uint8_t      _i2c_addr;
+    MMA845x_DATA _data;
+    
+    void init(void) const;
+};
+
+#endif