Diff: AK8975.h

Revision:

0:bceb91239894

Child:

1:76f65416ae1b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/AK8975.h	Mon May 07 11:36:18 2012 +0000
@@ -0,0 +1,175 @@
+/* Library for AK8975 digital compass IC, for use with I2C 
+
+This library contains basic functionality, if you want more, make it ;) 
+
+
+Example program:
+
+#include "mbed.h"
+#include "AK8975.h"
+
+DigitalOut led1(LED1);
+Serial pc(USBTX, USBRX); // tx, rx
+AK8975 mag(p9,p10,0x0E);
+
+
+int main() {
+    int data[3];
+    if (mag.testConnection())
+        pc.printf("Connection succeeded. \n");
+    else
+        pc.printf("Connection failed. \n");
+    
+     while(1) {
+        led1=!led1;
+        mag.startMeasurement();
+        wait(0.5);                      //(or use the isReady() function)
+        mag.getAll(data);
+        pc.printf("X: %d", data[0]);
+        pc.putc('\n');
+        pc.printf("Y: %d", data[1]);
+        pc.putc('\n');
+        pc.printf("Z: %d", data[2]);
+        pc.putc('\n');
+    }
+}
+         
+*/
+
+#ifndef AK8975_H
+#define AK8975_H
+
+/**
+ * Includes
+ */
+#include "mbed.h"
+
+/**
+ * Registers
+ */
+#define AK8975_ID_REG       0x00
+#define AK8975_ST1_REG      0x02
+#define AK8975_X_REG        0x03
+#define AK8975_Y_REG        0x05
+#define AK8975_Z_REG        0x07
+#define AK8975_ST2_REG      0x09
+#define AK8975_CONTROL_REG  0x0A
+#define AK8975_SELFTEST_REG 0x0C
+
+/**
+ * Bits
+ */
+#define AK8975_DRDY_BIT     0
+#define AK8975_DERROR_BIT   2
+#define AK8975_OFLOW_BIT    3
+
+#define AK8975_SINGLE_MEASUREMENT 1
+
+#define AK8975_SENSITIVITY  0.3
+
+class AK8975 {
+    public:
+     /**
+     * Constructor.
+     *
+     * @param sda - mbed pin to use for the SDA I2C line.
+     * @param scl - mbed pin to use for the SCL I2C line.
+     * @param I2Caddress - the I2C address of the device (0x0C - 0x0F)
+     */
+     AK8975(PinName sda, PinName scl, char address);
+     
+     /**
+     * Checks connection with the device.
+     *
+     * @return - true if working connection, otherwise false
+     */
+     bool testConnection( void );
+     
+     /**
+     * Checks if measurement is ready
+     *
+     * @return - true if available measurement, otherwise false
+     */
+     bool isReady( void );
+     
+     /**
+     * Gets the X data
+     *
+     * @return - signed integer containing the raw data
+     */
+     int getX( void );
+     
+     /**
+     * Gets the Y data
+     *
+     * @return - signed integer containing the raw data
+     */
+     int getY( void );
+     
+     /**
+     * Gets the Z data
+     *
+     * @return - signed integer containing the raw data
+     */
+     int getZ( void );
+     
+     /**
+     * Gets all the data, this is more efficient than calling the functions individually
+     *
+     * @param data - pointer to integer array with length 3 where data is stored (data[0]=X - data[1]=Y - data[2]=Z)
+     */
+     void getAll( int *data );
+     
+        
+     
+     /**
+     * Checks if there is a data error due to reading at wrong moment
+     *
+     * @return - true for error, false for no error
+     */
+     bool getDataError( void );
+     
+     /**
+     * Checks if a magnetic overflow happened (sensor saturation)
+     *
+     * @return - true for error, false for no error
+     */
+     bool getOverflow( void );
+     
+     /**
+     * Starts a measurement cycle
+     */
+     void startMeasurement( void );
+     
+     
+     
+     private:
+     I2C connection;
+     char deviceAddress;
+        
+     /**
+     * Writes data to the device
+     *
+     * @param adress - register address to write to
+     * @param data - data to write
+     */
+     void write( char address, char data);
+     
+     /**
+     * Read data from the device 
+     *
+     * @param adress - register address to write to
+     * @return - data from the register specified by RA
+     */
+     char read( char adress);
+     
+     /**
+     * Read multtiple regigsters from the device, more efficient than using multiple normal reads. 
+     *
+     * @param adress - register address to write to
+     * @param length - number of bytes to read
+     * @param data - pointer where the data needs to be written to 
+     */
+     void read( char adress, char *data, int length);
+};      
+#endif
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