Diff: MMA8451Q8.cpp

Revision:

5:5a7293378401

Parent:

3:db7126dbd63f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA8451Q8.cpp	Thu Dec 11 00:36:30 2014 +0000
@@ -0,0 +1,106 @@
+/* Copyright (c) 2010-2011 mbed.org, 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.
+*/
+// Modify to change full scale gravity range 141207 sc
+
+
+#include "MMA8451Q8.h"
+
+#define REG_WHO_AM_I      0x0D
+#define REG_CTRL_REG_1    0x2A
+#define REG_OUT_X_MSB     0x01
+#define REG_OUT_Y_MSB     0x03
+#define REG_OUT_Z_MSB     0x05
+#define XYZ_DATA_CFG      0x0E
+
+#define UINT14_MAX        16383
+
+#define MAX_2G            0x00
+#define MAX_4G            0x01
+#define MAX_8G            0x02
+
+#define NUM_DATA            2
+#define GSCALING          1024.0
+#define ADDRESS_INDEX       0
+#define DATA_INDEX          1
+
+float gScaling[3] = {4095.0,2048.0,1024.0}; //scaling for acceleration of gravity values
+
+MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
+    // activate the peripheral
+    uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
+    writeRegs(data, 2);
+}
+
+MMA8451Q::~MMA8451Q() { }
+
+uint8_t MMA8451Q::getWhoAmI() {
+    uint8_t who_am_i = 0;
+    readRegs(REG_WHO_AM_I, &who_am_i, 1);
+    return who_am_i;
+}
+void MMA8451Q::setGLimit(int gSelect) {   
+    uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00};
+    gChosen = gSelect;
+    writeRegs(data, NUM_DATA); // put in standby
+    data[ADDRESS_INDEX ] = XYZ_DATA_CFG;
+    data[DATA_INDEX] = gChosen;
+    writeRegs(data, 2);// change g limit
+    data[ADDRESS_INDEX ] = REG_CTRL_REG_1;
+    data[DATA_INDEX] = 0x01;
+    writeRegs(data, 2); // make active
+}
+
+float MMA8451Q::getAccX() {
+    return (float(getAccAxis(REG_OUT_X_MSB))/gScaling[gChosen]);
+}
+
+float MMA8451Q::getAccY() {
+    return (float(getAccAxis(REG_OUT_Y_MSB))/gScaling[gChosen]);
+}
+
+float MMA8451Q::getAccZ() {
+    return (float(getAccAxis(REG_OUT_Z_MSB))/gScaling[gChosen]);
+}
+
+void MMA8451Q::getAccAllAxis(float * res) {
+    res[0] = getAccX();
+    res[1] = getAccY();
+    res[2] = getAccZ();
+}
+
+int16_t MMA8451Q::getAccAxis(uint8_t addr) {
+    int16_t acc;
+    uint8_t res[2];
+    readRegs(addr, res, 2);
+
+    acc = (res[0] << 6) | (res[1] >> 2);
+    if (acc > UINT14_MAX/2)
+        acc -= UINT14_MAX;
+
+    return acc;
+}
+
+void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
+    char t[1] = {addr};
+    m_i2c.write(m_addr, t, 1, true);
+    m_i2c.read(m_addr, (char *)data, len);
+}
+
+void MMA8451Q::writeRegs(uint8_t * data, int len) {
+    m_i2c.write(m_addr, (char *)data, len);
+}