My version of the library for this accelerometer. It works on 800Hz data rate.

Dependents:   Acc_Logger midterm SDCardTest SDCardTest ... more

Files at this revision

API Documentation at this revision

Comitter:
quevedo
Date:
Wed Jun 04 19:16:47 2014 +0000
Commit message:
My version of MMA8451 library

Changed in this revision

MMA8451Q.cpp Show annotated file Show diff for this revision Revisions of this file
MMA8451Q.h Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r 7c9ab58f6af3 MMA8451Q.cpp
--- /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);
+}
\ No newline at end of file
diff -r 000000000000 -r 7c9ab58f6af3 MMA8451Q.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA8451Q.h	Wed Jun 04 19:16:47 2014 +0000
@@ -0,0 +1,80 @@
+/* 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.
+*/
+
+#ifndef MMA8451Q_H
+#define MMA8451Q_H
+
+#include "mbed.h"
+
+/**
+* MMA8451Q accelerometer example, 8-bit samples
+*
+* @code
+* #include "mbed.h"
+* #include "MMA8451Q.h"
+* 
+* int main(void) {
+* 
+* MMA8451Q acc(PTE25, PTE24);
+* PwmOut rled(LED_RED);
+* PwmOut gled(LED_GREEN);
+* PwmOut bled(LED_BLUE);
+* uint8_t data[3];
+*
+*     while (true) {
+          acc.getAccAllAxis(data);       
+*         rled = 1.0 - abs(data[0]/128);
+*         gled = 1.0 - abs(data[0]/128);
+*         bled = 1.0 - abs(data[0]/128);
+*         wait(0.4);
+*     }
+* }
+* @endcode
+*/
+class MMA8451Q
+{
+public:
+  /**
+  * MMA8451Q constructor
+  *
+  * @param sda SDA pin
+  * @param sdl SCL pin
+  */
+  MMA8451Q(PinName sda, PinName scl);
+
+  /**
+  * MMA8451Q destructor
+  */
+  ~MMA8451Q();
+
+  /**
+   * Get XYZ axis acceleration, 8-bits
+   *
+   * @param res array where acceleration data will be stored
+   */
+  void getAccAllAxis(int16_t * res);
+
+private:
+  I2C m_i2c;
+  void readRegs(int addr, uint8_t * data, int len);
+  void writeRegs(uint8_t * data, int len);
+
+};
+
+#endif
\ No newline at end of file