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:
17:6e4232c421c0
Parent:
16:d6dde2318edc
Child:
18:27d839e6dc0e
diff -r d6dde2318edc -r 6e4232c421c0 MMA8452.h
--- a/MMA8452.h	Wed Mar 05 16:47:13 2014 +0000
+++ b/MMA8452.h	Wed Mar 05 17:01:00 2014 +0000
@@ -21,10 +21,6 @@
 
 // the SparkFun breakout board defaults to 1, set to 0 if SA0 jumper on the bottom of the board is set
 // see the Table 10. I2C Device Address Sequence in Freescale MMA8452Q pdf
-
-
-#define DBG(...) pc.printf(__VA_ARGS__); pc.printf("\r\n");
-#define DBGX(...) pc.print(__VA_ARGS__);
  
 #include "mbed.h" 
 
@@ -238,7 +234,9 @@
       DataRateHz getDataRate();
       BitDepth getBitDepth();
       
+      #ifdef MMA8452_DEBUG
       void debugRegister(char reg);
+      #endif
    
     private:
       int readRaw(char src, char *dst, int len);