+ refactor

+ added timing
+ fixed some bugs

libraries/hmc6532/Readme.txt

@@ -0,0 +1,12 @@
+
+This library is BETA, only tested partially and not thoroughly
+
+No guarantees, use at own risk, all disclaimers apply 
+
+The example sketch can be used to config the compass.
+
+For switching operational mode one must reboot the system.
+
+
+
+

libraries/hmc6532/examples/continuousDemo/continuousDemo.pde

@@ -0,0 +1,53 @@
+// 
+//    FILE: continuousDemo.pde
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.00
+// PURPOSE: demo app HMC6352 library - continuous mode for Arduino
+//
+// HISTORY: 
+// 0.1.00 - 2011-04-12 initial version
+// 
+// Released to the public domain
+//
+// All disclaimers apply use at own risk
+//
+
+#include <Wire.h>
+#include <hmc6352.h>
+
+hmc6352 Compass(0x21);  // 0x21 <==> 33  <==> 66 >> 1
+
+void setup()
+{
+  Serial.begin(19200);
+  Serial.println("HMC6352: Version ");
+  Serial.println(HMC_LIB_VERSION);
+  Serial.print("current output modus");
+  Serial.println(Compass.getOutputModus());
+  
+  x = Compass.askHeading();
+  //Serial.print("Ask returns: ");
+  //Serial.println(x);  
+}
+int x;
+
+void loop()
+{
+  // in continuous mode it is not needed to ask for a new reading every time
+  // as it will do a new reading continuously even when not asked for
+  // Try making a fast turn and see the difference with the query mode
+  x = Compass.readHeading();
+  Serial.print("Degree : ");
+  Serial.println(x);
+  delay(1000);
+}
+// END OF FILE
+
+
+
+
+
+
+
+
+

libraries/hmc6532/examples/hmc6352Config/hmc6352Config.pde

@@ -0,0 +1,249 @@
+// 
+//    FILE: hmc6352Config.pde
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.00
+// PURPOSE: test app HMC6352 library for Arduino
+//
+// Released to the public domain
+//
+
+#include <Wire.h>
+#include <hmc6352.h>
+
+hmc6352 Compass(33);
+
+void setup()
+{
+  Serial.begin(19200);
+  Serial.println("HMC6352: Config");
+  Serial.println(HMC_LIB_VERSION);
+
+  dumpEEPROM();
+}
+int x;
+
+void loop()
+{
+  // SHOWMENU
+  Serial.println("\n\n\t\tHMC6352 MENU\n");
+  Serial.println("F : Factory Reset");
+  Serial.println("E : Dump EEPROM & 2 RAM addresses");
+
+  Serial.println("R : Dump RAM");
+
+  Serial.println("A : ask sampling");
+  Serial.println("Q : read sample");
+  Serial.println("Z : continuous read (loop) - X to stop");
+
+  Serial.println("W : WakeUp");
+  Serial.println("S : Sleep");
+
+  Serial.println("O : Output Modus Menu");
+  Serial.println("7 : STANDBY MODE");
+  Serial.println("8 : QUERY MODE");
+  Serial.println("9 : CONTINUOUS MODE");
+
+  Serial.println("C : Callibration On (!!)");
+  Serial.println("X : Callibration Off (!!)");
+
+  Serial.println("I : set I2C address (!!)");
+  Serial.println("@ : reset (!!)");
+
+  Serial.println("Enter your choice ...");
+
+  // WAIT FOR COMMAND
+  while (Serial.available() == 0);
+  char cmd = Serial.read();
+
+  // EXECUTE COMMAND
+  switch(cmd)
+  {
+  case 'F': 
+    factoryReset();
+    break;
+  case 'E': 
+    dumpEEPROM();
+    break;
+  case 'R': 
+    dumpRAM();
+    break;
+  case 'A': 
+    askHeading();
+    break;
+  case 'Q': 
+    readHeading();
+    break;
+  case 'W': 
+    x = Compass.wakeUp();
+    Serial.println(x, DEC);
+    break;
+  case 'S': 
+    x = Compass.sleep();
+    Serial.println(x, DEC);
+    break;
+  case 'O': 
+    OutPutModusMenu();
+    break;
+  case '7': 
+    // mode , freq , reset
+    Compass.setOperationalModus(STANDBY, 1, true);  // 10 default val
+    Serial.println("Reboot Arduino");
+    break;
+  case '8': 
+    Compass.setOperationalModus(QUERY, 1, true);  // 10 default val
+    Serial.println("Reboot Arduino");
+    break;
+  case '9': 
+    Compass.setOperationalModus(CONT, 20, true);  // 10 default val
+    Serial.println("Reboot Arduino");
+    break;
+  case 'U': 
+    Compass.callibrationOn();
+    break;
+  case 'X': 
+    Compass.callibrationOff();
+    break;
+  case 'I': 
+    setI2Caddress();
+    break;
+  case '@': 
+    Compass.updateOffsets();
+    break;
+  case 'Z': 
+    while (1)
+    {
+      readHeading();
+      if (Serial.available()>0) 
+      {
+        Serial.read();
+        break;
+      }
+      delay(50);  // 20 Hz
+    }     
+    break;
+  default: 
+    break; 
+  }
+}
+
+void OutPutModusMenu()
+{
+  Serial.println(Compass.getOutputModus());
+  Serial.println("output modus value :");
+  Serial.println("0 Heading (default)");
+  Serial.println("1 Raw Magnetometer X"); 
+  Serial.println("2 Raw Magnetometer Y"); 
+  Serial.println("3 Magnetometer X"); 
+  Serial.println("4 Magnetometer Y");
+  // WAIT FOR PARAM
+  while (Serial.available() == 0);
+  char cmd = Serial.read();
+  cmd -= '0'; // make a digit out of it
+  int x = Compass.setOutputModus(cmd);
+  Serial.print("Returns: ");
+  Serial.println(x);
+} 
+
+void askHeading() 
+{
+  int x = Compass.askHeading();
+  Serial.print("Returns: ");
+  Serial.println(x);  
+}
+
+void readHeading() 
+{
+  int x = Compass.readHeading();
+  Serial.print("DEGREE: ");
+  Serial.println(x);
+}
+
+void factoryReset()
+{
+  Compass.factoryReset();
+  Serial.println("Reboot Arduino");
+}
+
+void dumpRAM()
+{
+  Serial.println("\nDUMP RAM: (decimal values)");
+  Serial.println("Size 256 bytes (?) meaning mostly unknown");
+  for (int i = 0; i< 256; i++)
+  {
+    if (i % 16 == 0)
+    {
+      Serial.println();
+      Serial.print(i, HEX);
+      Serial.print(" : ");
+    }
+    Serial.print(Compass.readRAM(i), HEX);
+    Serial.print("\t ");
+  }
+  Serial.println();
+}
+
+void dumpEEPROM()
+{
+  Serial.println("\nDUMP EEPROM: (decimal values)");
+  Serial.println("Read datasheet for meaning\n");
+
+  Serial.print("      I2C ADDRESS: 0x00 : ");
+  Serial.println(Compass.readEEPROM(0), DEC);
+  Serial.print("MAGN X OFFSET MSB: 0x01 : ");
+  Serial.println(Compass.readEEPROM(1), DEC);
+  Serial.print("MAGN X OFFSET LSB: 0x02 : ");
+  Serial.println(Compass.readEEPROM(2), DEC);
+  Serial.print("MAGN Y OFFSET MSB: 0x03 : ");
+  Serial.println(Compass.readEEPROM(3), DEC);
+  Serial.print("MAGN Y OFFSET LSB: 0x04 : ");
+  Serial.println(Compass.readEEPROM(4), DEC);
+  Serial.print("       Time Delay: 0x05 : ");
+  Serial.println(Compass.readEEPROM(5), DEC);
+  Serial.print("  Measurement Sum: 0x06 : ");
+  Serial.println(Compass.readEEPROM(6), DEC);
+  Serial.print(" Software Version: 0x07 : ");
+  Serial.println(Compass.readEEPROM(7), DEC);
+  Serial.print(" Operational Mode: 0x08 : ");
+  Serial.println(Compass.readEEPROM(8), DEC);
+
+  Serial.println("REGISTERS RAM");
+  Serial.print("Operational Mode Control Byte: 0x74 : ");
+  Serial.println(Compass.getOperationalModus(), BIN);
+  Serial.print("Output Data Mode: 0x4E : ");
+  Serial.println(Compass.getOutputModus(), BIN);
+}
+
+void setI2Caddress()
+{
+  Serial.print("Current I2C address : ");
+  Serial.println(Compass.getI2CAddress());
+  Serial.println(); 
+  Serial.println("Give new value: (decimal, 2 digits)"); 
+  Serial.println("00 to escape"); 
+
+  while (Serial.available() < 2);
+  int v1 = Serial.read();
+  v1 -= '0';
+  v1 *= 10;
+  int v2 = Serial.read();
+  v2 -= '0';
+  v1 += v2;
+  if (v1 == 0) return;
+  Serial.println(v1);
+  int x = Compass.setI2CAddress(v1);
+  Serial.println(x);
+  Serial.print("Current I2C address : ");
+  Serial.println(Compass.getI2CAddress());
+
+} 
+
+// END OF FILE
+
+
+
+
+
+
+
+
+

libraries/hmc6532/examples/queryDemo/queryDemo.pde

@@ -0,0 +1,54 @@
+// 
+//    FILE: queryDemo.pde
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.00
+// PURPOSE: demo app HMC6352 library - query mode for Arduino
+//
+// HISTORY: 
+// 0.1.00 - 2011-04-12 initial version
+// 
+// Released to the public domain
+//
+// All disclaimers apply use at own risk
+//
+
+#include <Wire.h>
+#include <hmc6352.h>
+
+hmc6352 Compass(0x21);  // 0x21 <==> 33  <==> 66 >> 1
+
+void setup()
+{
+  Serial.begin(19200);
+  Serial.println("HMC6352: Version ");
+  Serial.println(HMC_LIB_VERSION);
+  Serial.print("current output modus");
+  Serial.println(Compass.getOutputModus());
+  
+  x = Compass.askHeading();
+  //Serial.print("Ask returns: ");
+  //Serial.println(x);  
+}
+int x;
+
+void loop()
+{
+  // in query mode it is not needed to ask for a new reading every time
+  // as it will do a new reading directly after the chip is read
+  // and waits until it is asked for.
+  // Try making a fast turn and smile ...
+  x = Compass.readHeading();
+  Serial.print("Degree : ");
+  Serial.println(x);
+  delay(1000);
+}
+// END OF FILE
+
+
+
+
+
+
+
+
+

libraries/hmc6532/examples/set2continuous/set2continuous.pde

@@ -0,0 +1,68 @@
+// 
+//    FILE: set2continuous.pde
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.00
+// PURPOSE: Reset HMC6352 to continuous mode 
+//
+// HISTORY: 
+// 0.1.00 - 2011-04-12 initial version
+// 
+// Released to the public domain
+//
+// All disclaimers apply use at own risk
+//
+
+#include <Wire.h>
+
+int HMC = 0x21; 
+int ledPin = 13;
+boolean ledState = LOW;
+byte value;
+int x;
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.print("HMC6352 : start - ");
+  Serial.println(HMC, HEX);
+
+  pinMode(ledPin, OUTPUT);
+
+  Wire.begin();
+  delay(1000); // give all things time to start
+}
+
+void loop()
+{
+  // flashing means not blocking
+  ledState = !ledState;
+  digitalWrite(ledPin, ledState);
+
+  // write continuous mode to RAM 0x74 and do an L command immediately after it
+  // pull out 5 volt if it reads back 0x72
+  Wire.beginTransmission(HMC);
+  Wire.send('G');
+  Wire.send(0x74);
+  Wire.send(0x72);   // 20 Hz | Reset = True | CONT
+  Wire.send('L');
+  // Wire.send('O');  optional reset  
+  x = Wire.endTransmission();
+  delay(10);
+  
+  // Read the EEPROM value for feedback as this is the next startup value
+  Wire.beginTransmission(HMC);
+  Wire.send('r');
+  Wire.send(0x07);
+  x = Wire.endTransmission();
+  delay(10);
+  
+  Wire.requestFrom(HMC, 1);      
+  i = 0;
+  while(Wire.available()  < 1);
+  value = Wire.receive();
+  Serial.print("Current Mode: ");
+  Serial.println((int)value, BIN);     
+} 
+
+
+

libraries/hmc6532/examples/set2query/set2query.pde

@@ -0,0 +1,70 @@
+// 
+//    FILE: Set2query.pde
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.00
+// PURPOSE: Reset HMC6352 to query mode
+//
+// HISTORY: 
+// 0.1.00 - 2011-04-12 initial version
+// 
+// Released to the public domain
+//
+// All disclaimers apply use at own risk
+//
+
+#include <Wire.h>
+
+int HMC = 0x21; 
+int ledPin = 13;
+boolean ledState = LOW;
+byte value;
+int x;
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.print("HMC6352 : start - ");
+  Serial.println(HMC, HEX);
+
+  pinMode(ledPin, OUTPUT);
+
+  Wire.begin();
+  delay(1000); // give all things time to start
+}
+
+void loop()
+{
+  // flashing means not blocking
+  ledState = !ledState;
+  digitalWrite(ledPin, ledState);
+
+  // write query mode to RAM 0x74 and do an L command immediately after it
+  // this is done to "break through" the continuous mode if needed
+  // pull out 5 volt if it reads back 0x50
+  Wire.beginTransmission(HMC);
+  Wire.send('G');
+  Wire.send(0x74);
+  Wire.send(0x51);   // 10 Hz | Reset = True | QUERY
+  Wire.send('L');
+  // Wire.send('O');  optional reset  
+  x = Wire.endTransmission();
+  delay(10);
+  
+  // Read the EEPROM value for feedback as this is the next startup value
+  Wire.beginTransmission(HMC);
+  Wire.send('r');
+  Wire.send(0x07);
+  x = Wire.endTransmission();
+  delay(10);
+  
+  Wire.requestFrom(HMC, 1);      
+  i = 0;
+  while(Wire.available()  < 1);
+  value = Wire.receive();
+  Serial.print("Current Mode: ");
+  Serial.println((int)value, BIN);     
+} 
+
+
+
+

libraries/hmc6532/examples/set2standby/set2standby.pde

@@ -0,0 +1,70 @@
+// 
+//    FILE: set2standby.pde
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.00
+// PURPOSE: Reset HMC6352 to standby mode (esp if it is struck in continuous mode - Arduino)
+//
+// HISTORY: 
+// 0.1.00 - 2011-04-12 initial version
+// 
+// Released to the public domain
+//
+// All disclaimers apply use at own risk
+//
+
+#include <Wire.h>
+
+int HMC = 0x21; 
+int ledPin = 13;
+boolean ledState = LOW;
+byte value;
+int x;
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.print("HMC6352 : start - ");
+  Serial.println(HMC, HEX);
+
+  pinMode(ledPin, OUTPUT);
+
+  Wire.begin();
+  delay(1000); // give all things time to start
+}
+
+void loop()
+{
+  // flashing means not blocking
+  ledState = !ledState;
+  digitalWrite(ledPin, ledState);
+
+  // write stdby mode to RAM 0x74 and do an L command immediately after it
+  // this is done to "break through" the continuous mode
+  // pull out 5 volt if it reads back 0x50
+  Wire.beginTransmission(HMC);
+  Wire.send('G');
+  Wire.send(0x74);
+  Wire.send(0x50);
+  Wire.send('L');
+  // Wire.send('O');  optional reset  
+  x = Wire.endTransmission();
+  delay(10);
+  
+  // Read the EEPROM value for feedback as this is the next startup value
+  Wire.beginTransmission(HMC);
+  Wire.send('r');
+  Wire.send(0x07);
+  x = Wire.endTransmission();
+  delay(10);
+  
+  Wire.requestFrom(HMC, 1);      
+  i = 0;
+  while(Wire.available()  < 1);
+  value = Wire.receive();
+  Serial.print("Current Mode: ");
+  Serial.println((int)value, BIN);     
+} 
+
+
+
+

libraries/hmc6532/examples/standbyDemo/standbyDemo.pde

@@ -0,0 +1,58 @@
+// 
+//    FILE: standbyDemo.pde
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.00
+// PURPOSE: demo app HMC6352 library - standby mode for Arduino
+//
+// HISTORY: 
+// 0.1.00 - 2011-04-12 initial version
+//
+// Released to the public domain
+//
+// All disclaimers apply use at own risk
+//
+
+#include <Wire.h>
+#include <hmc6352.h>
+
+hmc6352 Compass(0x21);  // 0x21 <==> 33  <==> 66 >> 1
+
+void setup()
+{
+  Serial.begin(19200);
+  Serial.println("HMC6352: Version ");
+  Serial.println(HMC_LIB_VERSION);
+  Serial.print("current output modus");
+  Serial.println(Compass.getOutputModus());
+}
+int x;
+
+void loop()
+{
+  Compass.wakeup(); // decent wake up from sleep mode
+  
+  // Note that reading a heading is requires two steps, ask() & read()
+  // this makes the query and continuous mode more efficient
+  // without impact on the footprint of the lib.
+  // a wrapper is an option.
+  x = Compass.askHeading();
+  //Serial.print("Ask returns: ");
+  //Serial.println(x);  
+  
+  x = Compass.readHeading();
+  Serial.print("Degree : ");
+  Serial.println(x);
+  
+  Compass.sleep();  // low energy mode
+  delay(500);
+}
+// END OF FILE
+
+
+
+
+
+
+
+
+

libraries/hmc6532/hmc6352.cpp

@@ -1,11 +1,13 @@
 // 
 //    FILE: hmc6352.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.00
+// VERSION: 0.1.02
 // PURPOSE: HMC6352 library for Arduino
 //
 // HISTORY: 
 // 0.1.00 - 2011-04-07 initial version
+// 0.1.01 - 2011-04-09 quite a complete redo 
+// 0.1.02 - 2011-04-12 added timing, fixed a bug
 // 
 // Released to the public domain
 //
@@ -14,70 +16,72 @@
 #include <Wire.h>
 #include "WProgram.h"
 
-
 /* ERROR CODES ALL FUNCTIONS
-
-// * twi_writeTo codes
+//
+// * twi_writeTo codes (== endTransmission  commands)
 //   0 .. OK
 //  -1 .. length to long for buffer
 //  -2 .. address send, NACK received
 //  -3 .. data send, NACK received
 //  -4 .. other twi error (lost bus arbitration, bus error, ..)
+//
 // * requestFrom 
-// -10 : not enough values returned
+// -10 .. not enough values returned
+//
+// * function calls
+//   0 .. OK
+// -20 .. error param1
+// -21 .. error param2
+// -22 .. error param3
+//
+// 
 */
 
-// >=0 == direction 
-// < 0 error code
 hmc6352::hmc6352(uint8_t device)
 {
 	Wire.begin();
 	_device = constrain(device, 0x10, 0xF6);
 }
 
-/* RETURN VALUES
-// >=0 == direction 
-// < 0 error code
-*/
-int hmc6352::direction()
+// Ask the device to make a new reading
+int hmc6352::askHeading()
 {
 	int rv = cmd(HMC_GET_DATA);
 	if (rv != 0) return -rv;   // problem with handshake
 	delay(6); // see datasheet, p8
-
-	// no need for wire.available()...
-	rv = Wire.requestFrom(_device, (uint8_t)2);  // remove ambiguity
-	if (rv != 2) return -10; 
-	rv = Wire.receive() * 256;
-	rv += Wire.receive();
 	return rv;
 }
 
-int hmc6352::qry()
+// read the last value from the
+int hmc6352::readHeading()
 {
-	// no need for wire.available()...
 	int rv = Wire.requestFrom(_device, (uint8_t)2);  // remove ambiguity
 	if (rv != 2) return -10;
-	rv = Wire.receive() * 256;
-	rv += Wire.receive();
+	rv = Wire.receive() * 256;  // MSB
+	rv += Wire.receive();       // LSB
 	return rv;
 }
 
+// wake up from energy saving modus
 int hmc6352::wakeUp()
 {
-	return cmd(HMC_WAKE); 
+	int rv =  cmd(HMC_WAKE);
+	delayMicroseconds(100);
+	return rv;
 }
 
+// go into energy saving modus
 int hmc6352::sleep()
 {
-	return cmd(HMC_SLEEP); 
+	int rv = cmd(HMC_SLEEP);
+	delayMicroseconds(10);
+	return rv;
 }
 
 // values obtained from dump
 int hmc6352::factoryReset()
 {
-    writeRAM(0x74, 0x50);
-
+	writeRAM(0x74, 0x50); // is needed !!
 	writeCmd(HMC_WRITE_EEPROM, 0, 66);
 	writeCmd(HMC_WRITE_EEPROM, 1, 0);
 	writeCmd(HMC_WRITE_EEPROM, 2, 0);
@@ -86,20 +90,14 @@ int hmc6352::factoryReset()
 	writeCmd(HMC_WRITE_EEPROM, 5, 1);
 	writeCmd(HMC_WRITE_EEPROM, 6, 4);
 	writeCmd(HMC_WRITE_EEPROM, 7, 6);
-	writeCmd(HMC_WRITE_EEPROM, 8, 80);
-	cmd(HMC_SLEEP); 
-	delay(1000);
-	cmd(HMC_WAKE); 
+	writeCmd(HMC_WRITE_EEPROM, 8, 0x50);
+	cmd(HMC_SAVE_OP_MODE);
+	delayMicroseconds(125);
 	return 0;
 }
 
 // HANDLE WITH CARE - RESTART NECESSARY
-/* RETURN VALUES
-     0 = OK
-   -20 = illegal param1
-   -21 = illegal param1
-   -22 = illegal param2
-*/
+// Returns Operational Mode Config Byte
 int hmc6352::setOperationalModus(hmcMode m, uint8_t freq, bool periodicReset)
 {
 	byte omcb = 0;  // Operational Mode Control Byte
@@ -124,56 +122,69 @@ int hmc6352::setOperationalModus(hmcMode m, uint8_t freq, bool periodicReset)
 
 	writeCmd(HMC_WRITE_RAM, 0x74, omcb);
 	cmd(HMC_SAVE_OP_MODE);
-	return 0;
-} 
-
-int hmc6352::SaveOpMode()
-{
-	return cmd(HMC_SAVE_OP_MODE);
+	delayMicroseconds(125);
+	return omcb;
 } 
 
+// read the Operational Modus as byte from EEPROM
+// TODO: split into 3 items
+//
 int hmc6352::getOperationalModus()
 {
-	// readCmd(HMC_READ_RAM, 0x74);
-	return readCmd(HMC_READ_EEPROM, 0x08);
+	// datasheet state that at startup the OM is copied from EEPROM
+	// and that after writing to RAM a reboot is needed to enable new settings
+	// my interpretation ==> EEPROM is leading
+	return readCmd(HMC_READ_RAM, 0x74);
+	//return readCmd(HMC_READ_EEPROM, 0x08);
 }
 
-// WARNING DANGEROUS
-//
-/* RETURN VALUES
-//   0 = OK
-// -20 = illegal param1
-*/
+// Switch between normal heading and raw modes
+// default = 0 ==> normal headings
+// Note: after a reboot the output modus will be 0 again.
 int hmc6352::setOutputModus(uint8_t om)
 {
 	if (om > 4) return -20;
 	return writeCmd(HMC_WRITE_RAM, 0x4E, om);
 }
 
+// Read the output modus from RAM
 int hmc6352::getOutputModus()
 {
 	return readCmd(HMC_READ_RAM, 0x4E);
 }
 
-/* RETURN VALUES
-//   0 = OK
-// -20 = illegal param1
-*/
-int hmc6352::setI2Caddress(uint8_t address)
+// NOT TESTED
+int hmc6352::callibrationOn()
+{
+	int rv = cmd(HMC_CALLIBRATE_ON);
+	delayMicroseconds(10);
+	return rv;
+}
+
+// NOT TESTED
+int hmc6352::callibrationOff()
+{
+	int rv = cmd(HMC_CALLIBRATE_OFF);
+	delay(15);
+	return rv;
+}
+
+// NOT TESTED
+int hmc6352::setI2CAddress(uint8_t address)
 {
 	if (address < 0x10 || address > 0xF6 ) return -20;
 	return writeCmd(HMC_WRITE_EEPROM, 0, address);
 }
 
-int hmc6352::getI2Caddress()
+// returns current I2C address
+int hmc6352::getI2CAddress()
 {
 	return readCmd(HMC_READ_EEPROM, 0);
 }
 
-/* RETURN VALUES
-//   0 = OK
-// -20 = illegal param1
-*/
+// NOT TESTED
+// meaning time delay unknown
+// therefore removed from lib for now
 int hmc6352::setTimeDelay(uint8_t msec)
 {
 	return writeCmd(HMC_WRITE_EEPROM, 5, msec);
@@ -184,6 +195,9 @@ int hmc6352::getTimeDelay()
 	return readCmd(HMC_READ_EEPROM, 5);
 }
 
+// NOT TESTED
+// meaning measurement summing unknown
+// therefore removed from lib for now
 int hmc6352::setMeasurementSumming(uint8_t ms)
 {
 	if (ms > 16 ) ms = 16;
@@ -195,49 +209,63 @@ int hmc6352::getMeasurementSumming()
 	return readCmd(HMC_READ_EEPROM, 6);
 }
 
-
-int hmc6352::UserCallibrationOn()
+// Makes only sense in setOperationalModus()
+// therefore removed from lib for now
+int hmc6352::saveOpMode()
 {
-	return cmd(HMC_CALLIBRATE_ON);
+	int rv = cmd(HMC_SAVE_OP_MODE);
+	delayMicroseconds(125);
+	return rv;
 }
 
-int hmc6352::UserCallibrationOff()
+
+// NOT TESTED
+// meaning UpdateOffsets unknown
+// therefore removed from lib for now
+int hmc6352::updateOffsets()
 {
-	return cmd(HMC_CALLIBRATE_OFF);
-}
-
-int hmc6352::UpdateOffsets()
-{
-	return cmd(HMC_UPDATE_OFFSETS);
+	int rv = cmd(HMC_UPDATE_OFFSETS);
+	delay(6);
+	return rv;
 }
 
+// idem
+// use at own risk ...
 int hmc6352::writeEEPROM(uint8_t address, uint8_t data)
 {
 	return writeCmd(HMC_WRITE_EEPROM, address, data);
 }
 
+// idem
 int hmc6352::readEEPROM(uint8_t address)
 {
 	return readCmd(HMC_READ_EEPROM, address);
 }
 
+
+// idem
+// Most RAM locations have an unknown meaning
+// use at own risk ...
 int hmc6352::writeRAM(uint8_t address, uint8_t data)
 {
 	return writeCmd(HMC_WRITE_RAM, address, data);
 }
-
+// idem
 int hmc6352::readRAM(uint8_t address)
 {
 	return readCmd(HMC_READ_RAM, address);
 }
 
 /* PRIVATE FUNCTIONS
+   mostly to remove redundancy in functions above
 */
 int hmc6352::cmd(uint8_t c)
 {
 	Wire.beginTransmission(_device);
 	Wire.send(c);
-	return Wire.endTransmission();
+	int rv = Wire.endTransmission();
+	delay(10);
+	return rv;
 }
 
 int hmc6352::readCmd(uint8_t c, uint8_t address)
@@ -248,6 +276,8 @@ int hmc6352::readCmd(uint8_t c, uint8_t address)
 	int rv = Wire.endTransmission();
 	if (rv != 0) return -rv;
 	
+	delayMicroseconds(70);
+	
 	rv = Wire.requestFrom(_device, (uint8_t)1);
 	if (rv != 1) return -10; 
 	rv = Wire.receive();
@@ -260,5 +290,7 @@ int hmc6352::writeCmd(uint8_t c, uint8_t address, uint8_t data)
 	Wire.send(c); 
 	Wire.send(address); 
 	Wire.send(data); 
-	return Wire.endTransmission();
+	int rv = Wire.endTransmission();
+	delayMicroseconds(70);
+	return rv;
 }

libraries/hmc6532/hmc6352.h

@@ -1,7 +1,7 @@
 // 
 //    FILE: hmc6352.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.00
+// VERSION: 0.1.02
 // PURPOSE: HMC6352 library for Arduino
 //
 // DETAILS: see cpp file
@@ -14,7 +14,7 @@
 
 #include "Wprogram.h"
 
-#define HMC_LIB_VERSION 	"0.1.00"
+#define HMC_LIB_VERSION 	"0.1.01"
 
 #define HMC_GET_DATA		0x41
 #define HMC_WAKE			0x57
@@ -35,38 +35,45 @@ class hmc6352
 	public:
     hmc6352(uint8_t device);
 
-    int direction(void);
-    int qry(void);
+	// BASIC CALLS FOR STANDBY MODE
+    int askHeading(void);
+    int readHeading(void);
+
     int wakeUp(void);
     int sleep(void);
 
-	int UserCallibrationOn(void);
-	int UserCallibrationOff(void);
-
+	// REST
 	int factoryReset();
 
 	int setOperationalModus(hmcMode m, uint8_t freq, bool periodicReset);
 	int getOperationalModus();
+
 	int setOutputModus(uint8_t om);
 	int getOutputModus();
 
-	int setI2Caddress(uint8_t address);
-	int getI2Caddress();
+	int callibrationOn(void);
+	int callibrationOff(void);
 
-	int setTimeDelay(uint8_t msec);
-	int getTimeDelay();
-	
-	int setMeasurementSumming(uint8_t ms);
-	int getMeasurementSumming();
-
-	int SaveOpMode(void);
-	int UpdateOffsets(void);
+	int setI2CAddress(uint8_t address);
+	int getI2CAddress();
 
 	int writeEEPROM(uint8_t address, uint8_t data);
 	int readEEPROM(uint8_t address);
+	
 	int writeRAM(uint8_t address, uint8_t data);
 	int readRAM(uint8_t address);
 
+
+	// NOT TESTED / UNKNOWN
+	int setTimeDelay(uint8_t msec);
+	int getTimeDelay();
+	int setMeasurementSumming(uint8_t ms);
+	int getMeasurementSumming();
+	int saveOpMode(void);  
+	int updateOffsets(void);
+
+
+
   private:
 	int cmd(uint8_t c);
 	int readCmd(uint8_t c, uint8_t address);