Diff: MMA8451Q.cpp

Revision:

0:7c9ab58f6af3

Child:

1:9c229882cd2b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA8451Q.cpp	Wed Jun 04 19:16:47 2014 +0000
@@ -0,0 +1,75 @@
+/* Copyright (c) 2010-2011 mbed.org, MIT License
+* Copyright (c) 2014 Antonio Quevedo, UNICAMP
+*
+* 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.
+*/
+
+#include "MMA8451Q.h"
+
+#define ACCEL_I2C_ADDRESS 0x1D<<1
+#define REG_STATUS        0x00
+#define REG_XYZ_DATA_CFG  0x0E
+#define REG_WHO_AM_I      0x0D
+#define REG_CTRL_REG1     0x2A
+#define REG_CTRL_REG2     0x2B
+#define REG_CTRL_REG3     0x2C
+#define REG_CTRL_REG4     0x2D
+#define REG_CTRL_REG5     0x2E
+#define REG_OUT_X_MSB     0x01
+#define REG_OUT_Y_MSB     0x03
+#define REG_OUT_Z_MSB     0x05
+
+MMA8451Q::MMA8451Q(PinName sda, PinName scl) : m_i2c(sda, scl) {
+    uint8_t data[2] = {REG_CTRL_REG1, 0x00}; // Puts acc in standby for configuring
+    writeRegs(data, 2);
+    data[0] = REG_XYZ_DATA_CFG; // Writing 00 turns off high-pass filter and sets full scale range to 2g
+    // data[1] = 0x01; for 4g
+    // data[1] = 0x02; for 8g
+    writeRegs(data, 2);
+    data[0] = REG_CTRL_REG2;
+    data[1] = 0x00; // Disable self-test, software reset and auto-sleep; operates in normal mode
+    writeRegs(data, 2);
+    data[0] = REG_CTRL_REG3; // Interrupt polarity low, push-pull output
+    writeRegs(data, 2);
+    data[0] = REG_CTRL_REG4;
+    data[1] = 0x01; // Enables interrupt for data Ready
+    writeRegs(data, 2);
+    data[0] = REG_CTRL_REG5;
+    writeRegs(data, 2); // Routes Data Ready interrupt to INT1
+    data[0] = REG_CTRL_REG1; 
+    data[1] = 0x09; // Data rate is 800Hz
+    writeRegs(data, 2);
+}
+
+MMA8451Q::~MMA8451Q() { }
+
+void MMA8451Q::getAccAllAxis(int16_t * res) {
+    uint8_t temp[6];
+    readRegs(REG_OUT_X_MSB, temp, 6);
+    res[0] = (temp[0] * 256) + temp[1];
+    res[1] = (temp[2] * 256) + temp[3];
+    res[2] = (temp[4] * 256) + temp[5];
+}
+
+void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
+    char t[1] = {addr};
+    m_i2c.write(ACCEL_I2C_ADDRESS, t, 1, true);
+    m_i2c.read(ACCEL_I2C_ADDRESS, (char *)data, len);
+}
+
+void MMA8451Q::writeRegs(uint8_t * data, int len) {
+    m_i2c.write(ACCEL_I2C_ADDRESS, (char *)data, len);
+}
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