Diff: MMA7660.cpp

Revision:

0:7bc29a9ea016

Child:

1:8997a1b348dd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA7660.cpp	Sun Oct 14 08:02:53 2012 +0000
@@ -0,0 +1,123 @@
+#include "MMA7660.h"
+
+MMA7660::MMA7660(PinName sda, PinName scl, PinName interrupt) : _i2c(sda, scl)
+{
+    _interrupt = interrupt;
+    active = false;
+    samplerate = 120;
+}
+
+//Since the MMA lacks a WHO_AM_I register, we can only check if there is a device that answers to the I2C address
+bool MMA7660::testConnection( void )
+{
+    if (_i2c.write(MMA7660_ADDRESS, NULL, 0) == 0 )
+        return true;
+    else
+        return false;
+}
+
+void MMA7660::setActive(bool state)
+{
+    char modereg = read(MMA7660_MODE_R);
+    modereg &= ~(1<<0);
+
+    //If it somehow was in testmode, disable that
+    if (modereg && (1<<2)) {
+        modereg &= ~(1<<2);
+        write(MMA7660_MODE_R, modereg);
+    }
+
+    modereg += state;
+    write(MMA7660_MODE_R, modereg);
+}
+
+//Add timeout!
+void MMA7660::readData(int *data)
+{
+    if (!active) {
+        setActive(true);
+        active = true;
+    }
+
+    char temp[3];
+    bool alert;
+
+    do {
+        alert = false;
+        read(MMA7660_XOUT_R, temp, 3);
+        for (int i = 0; i<3; i++) {
+            if (temp[i] > 63)
+                alert = true;
+            if (temp[i] > 31)
+                temp[i] += 128+64;
+            data[i] = (signed char)temp[i];
+        }
+    } while (alert);
+}
+
+void MMA7660::readData(float *data)
+{
+    int intdata[3];
+    readData(intdata);
+    for (int i = 0; i<3; i++)
+        data[i] = intdata[i]/MMA7660_SENSITIVITY;
+}
+
+float MMA7660::getX( void ) {
+    return getSingle(0);
+    }
+
+float MMA7660::getY( void ) {
+    return getSingle(1);
+    }
+    
+float MMA7660::getZ( void ) {
+    return getSingle(2);
+    }        
+
+void MMA7660::write(char address, char data)
+{
+    char temp[2];
+    temp[0]=address;
+    temp[1]=data;
+
+    _i2c.write(MMA7660_ADDRESS, temp, 2);
+}
+
+char MMA7660::read(char address)
+{
+    char retval;
+    _i2c.write(MMA7660_ADDRESS, &address, 1, true);
+    _i2c.read(MMA7660_ADDRESS, &retval, 1);
+    return retval;
+}
+
+void MMA7660::read(char address, char *data, int length)
+{
+    _i2c.write(MMA7660_ADDRESS, &address, 1, true);
+    _i2c.read(MMA7660_ADDRESS, data, length);
+}
+
+float MMA7660::getSingle( int number )
+{
+    if (!active) {
+        setActive(true);
+        active = true;
+    }
+
+    signed char temp;
+    bool alert;
+
+    do {
+        alert = false;
+        temp = read(MMA7660_XOUT_R + number);
+        if (temp > 63)
+            alert = true;
+        if (temp > 31)
+            temp += 128+64;
+    }
+
+    while (alert);
+
+    return temp / MMA7660_SENSITIVITY;
+}
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