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.cpp

Revision:
2:66db0f91b215
Parent:
1:ef026bf28798
Child:
3:ffb0b1650ca2
--- 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();