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.

Files at this revision

API Documentation at this revision

Revision 2:66db0f91b215, committed 2013-10-08

Comitter:
nherriot
Date:
Tue Oct 08 16:13:14 2013 +0000
Parent:
1:ef026bf28798
Child:
3:ffb0b1650ca2
Commit message:
whoami tested and working

Changed in this revision

MMA8452.cpp Show annotated file Show diff for this revision Revisions of this file
MMA8452.h Show annotated file Show diff for this revision Revisions of this file 
--- a/MMA8452.cpp	Tue Oct 08 15:25:32 2013 +0000
+++ b/MMA8452.cpp	Tue Oct 08 16:13:14 2013 +0000
@@ -74,7 +74,7 @@
 
 
 // Get device ID 
-int Accelerometer_MMA8452::Get_DeviceID(int *deviceID)
+int Accelerometer_MMA8452::get_DeviceID(int& deviceID)
 {
     char mcu_address = (MMA8452_ADDRESS<<1);
     int z = 0;
@@ -102,7 +102,7 @@
         return 1;
     }
     wait( 0.1);
-    //deviceID  = m_i2c.read(0);
+    deviceID  = m_i2c.read(0);
     z = m_i2c.read(0);
     wait( 0.1);
     m_i2c.stop();

--- a/MMA8452.h	Tue Oct 08 15:25:32 2013 +0000
+++ b/MMA8452.h	Tue Oct 08 16:13:14 2013 +0000
@@ -151,7 +151,7 @@
         * return 0 for success or
         * return 1 for failure.
         */        
-      int Get_DeviceID(int *deviceID);    
+      int get_DeviceID(int& deviceID);    
        /** Read the Tilt Angle using Three Axis
         *
         * @param *x Value of x tilt