Diff: MMA845x.cpp

Revision:

0:9d1e3a344e4f

Child:

1:41af2b3eefb5

--- /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;
+}
+