Ashley Mills / MMA8452

Library for driving the MMA8452 accelerometer over I2C

Dependents:   MMA8452_Test MMA8452_Demo Dualing_Tanks IMU-Controlled_MP3_Player ... more

Here is a simple example:

#include "mbed.h"
#include "MMA8452.h"

int main() {
   Serial pc(USBTX,USBRX);
   pc.baud(115200);
   double x = 0, y = 0, z = 0;

   MMA8452 acc(p28, p27, 40000);
   acc.setBitDepth(MMA8452::BIT_DEPTH_12);
   acc.setDynamicRange(MMA8452::DYNAMIC_RANGE_4G);
   acc.setDataRate(MMA8452::RATE_100);
   
   while(1) {
      if(!acc.isXYZReady()) {
         wait(0.01);
         continue;
      }
      acc.readXYZGravity(&x,&y,&z);
      pc.printf("Gravities: %lf %lf %lf\r\n",x,y,z);
   }
}

An easy way to test that this actually works is to run the loop above and hold the MMA8452 parallel to the ground along the respective axis (and upsidedown in each axis). You will see 1G on the respective axis and 0G on the others.

Diff: MMA8452.h

Revision:
5:b3d0abd97e55
Parent:
3:ffb0b1650ca2
Child:
6:f6bde04bf8be
--- a/MMA8452.h	Wed Oct 16 16:26:26 2013 +0000
+++ b/MMA8452.h	Wed Oct 16 18:55:16 2013 +0000
@@ -187,6 +187,16 @@
       int standby();
 
  
+       /** get_CTRL_Reg1 the MMA8452 (not required)
+        *   returns 0 for success in activating the chip
+        *   returns 1 for failure in activating the chip
+        *   -currrently no retries or waiting is done, this method tries 1 time the exits.
+        *
+        *   This will return the state of the control register 1. This holds and sets values for auto wake, sleep mode
+        *   output data rate, fast read mode and active/standby. More info on 6.7 of pdf for MMA8452 Freescale doc.
+      */
+      int get_CTRL_Reg1(int& CTRL_Reg); 
+      
       
        /** Initialization of device MMA8452 (required)
         */