Diff: MMA8451.cpp

Revision:

0:f1c020594c48

Child:

1:13c3035afa27

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA8451.cpp	Wed Oct 02 08:29:41 2019 +0000
@@ -0,0 +1,166 @@
+/**
+ * @file      MMA8451.cpp
+ * @brief     Driver for the MMA8451 3-axis Accelerometer
+ * @author    Wilmin Ceballos (wceballos)
+ * @version   1.0
+ * @copyright MIT License
+ *
+ * Copyright (c) 2019 Wilmin Ceballos
+ *
+ * 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 "MMA8451.h"
+
+MMA8451::MMA8451(I2C &i2c, uint8_t i2cAddr) {
+  _i2c = &i2c;
+  _i2cAddr = static_cast<uint8_t>(i2cAddr) << 1;
+
+  _i2c->frequency(MMA8451_I2C_CLOCK);
+  init();
+}
+
+MMA8451::~MMA8451() {
+
+}
+
+bool MMA8451::init() {
+
+  if(id() != 0x1A)
+    return false;
+
+  writeRegister(MMA8451_CTRL_REG2, 0x40); // Trigger soft reset
+  // RST bit in CTRL_REG2 is deasserted when boot is finished
+  uint8_t content;
+  while(!readRegister(MMA8451_CTRL_REG2, &content) && (content & 0x40));
+  writeRegister(MMA8451_CTRL_REG1, 0x01); // Active mode
+  _sens = MMA8451_SENSITIVITY_2G;
+
+  return true;
+}
+
+void MMA8451::getXYZ() {
+  char ibuf[6] = {0}; // Incoming data
+  char baseReg = MMA8451_OUT_X_MSB;
+  
+  _i2c->write(_i2cAddr, &baseReg, 1, true);
+  _i2c->read(_i2cAddr, ibuf, 6, true);
+
+  // Data is 14 bits -> 0b00DDDDDD_DDDDDDDD
+  int16_t x_int = (static_cast<int16_t>(ibuf[0]))<<8 | ibuf[1]; x_int>>=2;
+  int16_t y_int = (static_cast<int16_t>(ibuf[2]))<<8 | ibuf[3]; y_int>>=2;
+  int16_t z_int = (static_cast<int16_t>(ibuf[4]))<<8 | ibuf[5]; z_int>>=2;
+
+  int16_t div = 1;
+  if(_sens == MMA8451_SENSITIVITY_2G)
+    div = 4096;
+  else if(_sens == MMA8451_SENSITIVITY_4G)
+    div = 2048;
+  else if(_sens == MMA8451_SENSITIVITY_8G)
+    div = 1024;
+
+  x = static_cast<float>(x_int) / div;
+  y = static_cast<float>(y_int) / div;
+  z = static_cast<float>(z_int) / div;
+}
+
+float MMA8451::getX() {
+  x = _readAxis(MMA8451_OUT_X_MSB);
+  return x;
+}
+
+float MMA8451::getY() {
+  y = _readAxis(MMA8451_OUT_Y_MSB);
+  return y;
+}
+
+float MMA8451::getZ() {
+  z = _readAxis(MMA8451_OUT_Z_MSB);
+  return z;
+}
+
+uint8_t MMA8451::id() {
+    readRegister(MMA8451_WHO_AM_I, &_whoami);
+    return _whoami;
+}
+
+bool MMA8451::readRegister(uint8_t reg, uint8_t *data) {
+  int status = _i2c->write(_i2cAddr, (char*)&reg, 1, true);
+  status |= _i2c->read(_i2cAddr, (char*)data, 1, true);
+  if(status != 0)
+    return false;
+  return true;
+}
+
+bool MMA8451::writeRegister(uint8_t reg, uint8_t data) {
+  char buf[2] = {reg, data};
+  int status = _i2c->write(_i2cAddr, buf, 2, true);
+  if(status != 0)
+    return false;
+  return true;
+}
+
+float MMA8451::_readAxis(uint8_t reg) {
+  char buf[2] = {0}; // Incoming data
+  
+  _i2c->write(_i2cAddr, (char*)&reg, 1, true);
+  _i2c->read(_i2cAddr, buf, 2, true);
+
+  // Data is 14 bits -> 0b00DDDDDD_DDDDDDDD
+  int16_t axisData = (static_cast<int16_t>(buf[0]))<<8 | buf[1]; axisData>>=2;
+
+  int16_t div = 1;
+  if(_sens == MMA8451_SENSITIVITY_2G)
+    div = 4096;
+  else if(_sens == MMA8451_SENSITIVITY_4G)
+    div = 2048;
+  else if(_sens == MMA8451_SENSITIVITY_8G)
+    div = 1024;
+    
+  return (static_cast<float>(axisData) / div);
+}
+
+void MMA8451::setStandbyMode() {
+  uint8_t content = 0;
+  uint8_t mask = 0xFE;
+  if(readRegister(MMA8451_CTRL_REG1, &content))
+    writeRegister(MMA8451_CTRL_REG1, content & mask);
+}
+
+void MMA8451::setActiveMode() {
+  uint8_t content = 0;
+  uint8_t mask = 0x01;
+  if(readRegister(MMA8451_CTRL_REG1, &content))
+    writeRegister(MMA8451_CTRL_REG1, content | mask);
+}
+
+void MMA8451::setDataRate(mma8451_dataRate_t rate) {
+  uint8_t content = 0;
+  uint8_t mask = (static_cast<uint8_t>(rate) << 3) & 0x38;
+  if(readRegister(MMA8451_CTRL_REG1, &content))
+    writeRegister(MMA8451_CTRL_REG1, content | mask);
+}
+
+void MMA8451::setSensitivity(mma8451_sensitivity_t sens) {
+  writeRegister(MMA8451_XYZ_DATA_CFG, sens);
+  _sens = sens;
+}
+
+