James Watanabe
Forked from Jose R. Padron and Aaron Berk's library, customized for my specific application using 9DoF-Stick by Sparkfun.
Fork of
HMC5843
by 
Jose R Padron
HMC5843 is triple axis, digital interface compass (geomagnetic sensor).
This library is forked from Jose R. Padron and Aaron Berk's work.
This library is for specific application using 9DoF-Stick.
Datasheet:
http://www.sparkfun.com/datasheets/Sensors/Magneto/HMC5843.pdf
HMC5843 は3軸のデジタルインターフェースを備えたコンパス（地磁気センサ）です。
このライブラリは 9DoF-Stick を使用した特定の企画のために保守しています。
mbed IDEが日本語をサポートするまでは英語でコメントを書いていきますが、サポートした後もきっと英語で書いていくでしょう。
Revision 4:7a90125eedcf, committed 2012-09-12
- Comitter:
- gltest26
- Date:
- Wed Sep 12 15:54:13 2012 +0000
- Parent:
- 3:69f24a492b69
- Child:
- 5:a83508250db7
- Commit message:
- Changed internal i2c_ object from a pointer to embedded object.; In this way you don't need to manage heap memory manually and can avoid overheads of memory management.
Changed in this revision
| HMC5843.cpp | Show annotated file Show diff for this revision Revisions of this file |
| HMC5843.h | Show annotated file Show diff for this revision Revisions of this file |
--- a/HMC5843.cpp Sun Sep 09 17:26:31 2012 +0000
+++ b/HMC5843.cpp Wed Sep 12 15:54:13 2012 +0000
@@ -1,4 +1,5 @@
/**
+ * @file HMC5843.cpp
* @author Jose R. Padron
* @author Used HMC6352 library developed by Aaron Berk as template
* @section LICENSE
@@ -32,16 +33,13 @@
* http://www.ssec.honeywell.com/magnetic/datasheets/HMC5843.pdf
*/
-/**
- * Includes
- */
+
#include "HMC5843.h"
-HMC5843::HMC5843(PinName sda, PinName scl) {
+HMC5843::HMC5843(PinName sda, PinName scl) : i2c_(sda, scl){
- i2c_ = new I2C(sda, scl);
//100KHz, as specified by the datasheet.
- i2c_->frequency(100000);
+ i2c_.frequency(100000);
}
@@ -54,7 +52,7 @@
tx[0]=address;
tx[1]=data;
- i2c_->write(HMC5843_I2C_WRITE,tx,2);
+ i2c_.write(HMC5843_I2C_WRITE,tx,2);
wait_ms(100);
@@ -82,11 +80,11 @@
tx[0]=HMC5843_IDENT_A;
- i2c_->write(HMC5843_I2C_WRITE, tx,1);
+ i2c_.write(HMC5843_I2C_WRITE, tx,1);
wait_ms(1);
- i2c_->read(HMC5843_I2C_READ,rx,3);
+ i2c_.read(HMC5843_I2C_READ,rx,3);
buffer[0]=rx[0];
buffer[1]=rx[1];
@@ -109,40 +107,19 @@
void HMC5843::readData(int* readings) {
-
-
- char tx[1];
-/* char rx[2];
-
-
- tx[0]=HMC5843_X_MSB;
- i2c_->write(HMC5843_I2C_READ,tx,1);
- i2c_->read(HMC5843_I2C_READ,rx,2);
- readings[0]= (int)int16_t(uint16_t(rx[0])<<8|uint16_t(rx[1]));
+ char tx[1] = {HMC5843_X_MSB};
+ i2c_.write(HMC5843_I2C_READ, tx, 1);
-
- tx[0]=HMC5843_Y_MSB;
- i2c_->write(HMC5843_I2C_READ,tx,1);
- i2c_->read(HMC5843_I2C_READ,rx,2);
- readings[1]= (int)int16_t(uint16_t(rx[0])<<8|uint16_t(rx[1]));
-
- tx[0]=HMC5843_Z_MSB;
- i2c_->write(HMC5843_I2C_READ,tx,1);
- i2c_->read(HMC5843_I2C_READ,rx,2);
- readings[2]= (int)int16_t(uint16_t(rx[0])<<8|uint16_t(rx[1]));*/
-
+ char rx[6];
// Burst read all registers to enhance bus speed.
- tx[0]=HMC5843_X_MSB;
- char rx[6];
- i2c_->write(HMC5843_I2C_READ, tx, 1);
- i2c_->read(HMC5843_I2C_READ, rx, 6);
+ i2c_.read(HMC5843_I2C_READ, rx, 6);
// Readings are expressed in 16bit 2's complement, so we must first
// concatenate two bytes to make a word and sign extend it to obtain
// correct negative values.
- readings[0] = int(int16_t(uint16_t(rx[0]) << 8 | uint16_t(rx[1])));
- readings[1] = int(int16_t(uint16_t(rx[2]) << 8 | uint16_t(rx[3])));
- readings[2] = int(int16_t(uint16_t(rx[4]) << 8 | uint16_t(rx[5])));
+ readings[0] = int(int16_t(unsigned(rx[0]) << 8 | unsigned(rx[1])));
+ readings[1] = int(int16_t(unsigned(rx[2]) << 8 | unsigned(rx[3])));
+ readings[2] = int(int16_t(unsigned(rx[4]) << 8 | unsigned(rx[5])));
}
@@ -153,8 +130,8 @@
tx[0]=HMC5843_X_MSB;
- i2c_->write(HMC5843_I2C_READ,tx,1);
- i2c_->read(HMC5843_I2C_READ,rx,2);
+ i2c_.write(HMC5843_I2C_READ,tx,1);
+ i2c_.read(HMC5843_I2C_READ,rx,2);
return ((int)rx[0]<<8|(int)rx[1]);
}
@@ -166,8 +143,8 @@
tx[0]=HMC5843_Y_MSB;
- i2c_->write(HMC5843_I2C_READ,tx,1);
- i2c_->read(HMC5843_I2C_READ,rx,2);
+ i2c_.write(HMC5843_I2C_READ,tx,1);
+ i2c_.read(HMC5843_I2C_READ,rx,2);
return ((int)rx[0]<<8|(int)rx[1]);
}
@@ -180,8 +157,8 @@
tx[0]=HMC5843_Z_MSB;
- i2c_->write(HMC5843_I2C_READ,tx,1);
- i2c_->read(HMC5843_I2C_READ,rx,2);
+ i2c_.write(HMC5843_I2C_READ,tx,1);
+ i2c_.read(HMC5843_I2C_READ,rx,2);
return ((int)rx[0]<<8|(int)rx[1]);
}
--- a/HMC5843.h Sun Sep 09 17:26:31 2012 +0000
+++ b/HMC5843.h Wed Sep 12 15:54:13 2012 +0000
@@ -1,4 +1,5 @@
/**
+ * @file HMC5843.h
* @author Jose R. Padron
* @author Used HMC5843 library developed by Aaron Berk as template
* @section LICENSE
@@ -35,14 +36,9 @@
#ifndef HMC5843_H
#define HMC5843_H
-/**
- * Includes
- */
#include "mbed.h"
-/**
- * Defines
- */
+
#define HMC5843_I2C_ADDRESS 0x1E //7-bit address. 0x3C write, 0x3D read.
#define HMC5843_I2C_WRITE 0x3C
#define HMC5843_I2C_READ 0x3D
@@ -208,8 +204,18 @@
int getStatus(void);
+private:
- I2C* i2c_;
+ /**
+ * Internal I2C object for communicating with the device.
+ *
+ * Changed from a pointer (new allocated object) from embedded object.
+ * The I2C class object is not meant to be allocated in the heap, but
+ * in the global storage.
+ * There's no point dynamically allocating an I2C object in this class,
+ * at least you should write destructor to release it!
+ */
+ I2C i2c_;