Glimit

Fork of MMA8451Q8 by Stanley Cohen

Files at this revision

API Documentation at this revision

Comitter:
mireyarod23
Date:
Wed Mar 08 05:15:45 2017 +0000
Parent:
7:7812354ef684
Commit message:
Attempt;

Changed in this revision

MMA8451Q8.cpp Show annotated file Show diff for this revision Revisions of this file
MMA8451Q8.h Show annotated file Show diff for this revision Revisions of this file
diff -r 7812354ef684 -r a515da97b396 MMA8451Q8.cpp
--- a/MMA8451Q8.cpp	Wed Feb 22 15:35:47 2017 +0000
+++ b/MMA8451Q8.cpp	Wed Mar 08 05:15:45 2017 +0000
@@ -33,7 +33,12 @@
 #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
@@ -48,27 +53,51 @@
     readRegs(REG_WHO_AM_I, &who_am_i, 1);
     return who_am_i;
 }
-void MMA8451Q::setGLimit() {   
+
+void MMA8451Q::setStandbyMode()
+{
+    #define ACTIVEMASK 0x01
+    uint8_t registerData[1];
+    uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00};
+    
+    readRegs(REG_CTRL_REG_1, registerData, 1);
+    data[1] = registerData[0] & ~ACTIVEMASK;
+    writeRegs(data, NUM_DATA); //put in standby
+}
+
+void MMA8451Q::setActiveMode()
+{
+    #define ACTIVEMASK 0x01
+    uint8_t registerData[1];
+    uint8_t data[NUM_DATA] = {REG_CTRL_REG_1, 0x00};
+    
+    readRegs(REG_CTRL_REG_1, registerData, 1);
+    data[1] = registerData[0] | ACTIVEMASK;
+    writeRegs(data, NUM_DATA);    
+}
+
+//seGLimit obtains index of the bit that needs to be changed
+void MMA8451Q::setGLimit(int gSelect) {   
     uint8_t data[2] = {REG_CTRL_REG_1, 0x00};
-    writeRegs(data, 2); // put in standby
-    data[0] = XYZ_DATA_CFG;
-    data[1] = MAX_8G;
-    writeRegs(data, 2);// change g limit
-    data[0] = REG_CTRL_REG_1;
-    data[1] = 0x01;
-    writeRegs(data, 2); // make active
+    gChosen = gSelect;
+    setStandbyMode();
+    
+    data[ADDRESS_INDEX ] = XYZ_DATA_CFG;
+    data[DATA_INDEX] = gChosen;
+    writeRegs(data, 2);
+    setActiveMode();
 }
 
 float MMA8451Q::getAccX() {
-    return (float(getAccAxis(REG_OUT_X_MSB))/GSCALING);
+    return (float(getAccAxis(REG_OUT_X_MSB))/gScaling[gChosen]);
 }
 
 float MMA8451Q::getAccY() {
-    return (float(getAccAxis(REG_OUT_Y_MSB))/GSCALING);
+    return (float(getAccAxis(REG_OUT_Y_MSB))/gScaling[gChosen]);
 }
 
 float MMA8451Q::getAccZ() {
-    return (float(getAccAxis(REG_OUT_Z_MSB))/GSCALING);
+    return (float(getAccAxis(REG_OUT_Z_MSB))/gScaling[gChosen]);
 }
 
 void MMA8451Q::getAccAllAxis(float * res) {
diff -r 7812354ef684 -r a515da97b396 MMA8451Q8.h
--- a/MMA8451Q8.h	Wed Feb 22 15:35:47 2017 +0000
+++ b/MMA8451Q8.h	Wed Mar 08 05:15:45 2017 +0000
@@ -97,16 +97,22 @@
    * @param res array where acceleration data will be stored
    */
   void getAccAllAxis(float * res);
-
-
+  
+  int16_t getAccAxis(uint8_t addr);
+  
   I2C m_i2c;
   int m_addr;
+  int gChosen;
+  
+  /** Allow user to get max g's **/
   void readRegs(int addr, uint8_t * data, int len);
   void writeRegs(uint8_t * data, int len);
-  void setGLimit(); 
+  void setGLimit(int gSelect);
+  void setStandbyMode();
+  void setActiveMode(); 
   
 private: 
-  int16_t getAccAxis(uint8_t addr);
+ 
 
 };