Changing HMC5883L registers to QMC5883L

Other Hardware Sensors
1

Hello, everybody. I have been working with the HMC5883L compass for a while now, and through much frustration and struggles, I have figured out that the HMC5883L is not on the market anymore, but its semi-clone, the QMC5883L is. However, I am using a code for GPS Guided Robotic car from online and it is a bit difficult to change the code, so I have decided to directly hack the HMC library and change all the registers in the cpp/ and h/ files in the library. Well, I have been trying for two days now, my Serial baud is 9600, and I am using the code below to calibrate my compass but to no avail. I am using this code

/*
  Calibrate HMC5883L. Output for HMC5883L_calibrate_processing.pde
  Read more: http://www.jarzebski.pl/arduino/czujniki-i-sensory/3-osiowy-magnetometr-hmc5883l.html
  GIT: https://github.com/jarzebski/Arduino-HMC5883L
  Web: http://www.jarzebski.pl
  (c) 2014 by Korneliusz Jarzebski
*/

#include <Wire.h>
#include <HMC5883L.h>

HMC5883L compass;

int minX = 0;
int maxX = 0;
int minY = 0;
int maxY = 0;
int offX = 0;
int offY = 0;

void setup()
{
  Serial.begin(9600);

  // Initialize Initialize HMC5883L
  while (!compass.begin())
  {
    delay(500);
  }

  // Set measurement range
  compass.setRange(HMC5883L_RANGE_1_3GA);

  // Set measurement mode
  compass.setMeasurementMode(HMC5883L_CONTINOUS);

  // Set data rate
  compass.setDataRate(HMC5883L_DATARATE_30HZ);

  // Set number of samples averaged
  compass.setSamples(HMC5883L_SAMPLES_8);
}

void loop()
{
  Vector mag = compass.readRaw();

  // Determine Min / Max values
  if (mag.XAxis < minX) minX = mag.XAxis;
  if (mag.XAxis > maxX) maxX = mag.XAxis;
  if (mag.YAxis < minY) minY = mag.YAxis;
  if (mag.YAxis > maxY) maxY = mag.YAxis;

  // Calculate offsets
  offX = (maxX + minX)/2;
  offY = (maxY + minY)/2;

  Serial.print(mag.XAxis);
  Serial.print(":");
  Serial.print(mag.YAxis);
  Serial.print(":");
  Serial.print(minX);
  Serial.print(":");
  Serial.print(maxX);
  Serial.print(":");
  Serial.print(minY);
  Serial.print(":");
  Serial.print(maxY);
  Serial.print(":");
  Serial.print(offX);
  Serial.print(":");
  Serial.print(offY);
  Serial.print("\n");
}

Well, no data is coming from the Serial Monitor. I also will attach the registers I changed. The code I am about to attach is the registers in .h file of the HMC5883L library to make the QMC work on the same library.

#define HMC5883L_ADDRESS              (0x0D) 
#define HMC5883L_REG_CONFIG_A         (0x0A) 
#define HMC5883L_REG_CONFIG_B         (0x0B) 
#define HMC5883L_REG_MODE             (0x09) 
#define HMC5883L_REG_OUT_X_M          (0x01) 
#define HMC5883L_REG_OUT_X_L          (0x00) 
#define HMC5883L_REG_OUT_Z_M          (0x05) 
#define HMC5883L_REG_OUT_Z_L          (0x04) 
#define HMC5883L_REG_OUT_Y_M          (0x03) 
#define HMC5883L_REG_OUT_Y_L          (0x02) 
#define HMC5883L_REG_STATUS           (0x0C) 
#define HMC5883L_REG_IDENT_A          (0x06) 
#define HMC5883L_REG_IDENT_B          (0x07) 
#define HMC5883L_REG_IDENT_C          (0x08)

NOTE: THIS CODE ABOVE IS FOR THE .H FILE FOR THE HMC5883L AFTER I CHANGED THE REGISTERS TO QMC REGISTERS

Does anybody know what my problem is?

Best regards, Daniel

2

Much easier to use one of the QMC5883 libraries instead. Only minor changes to calling programs are required.

3

I understand, sir. I am currently working on project using code for HMC5883L, and I simply don't have time or knowledge to change code to my liking. May you please guide me, because I have been working on this for a while and am getting lost. Here is a link for tutorial code for the project:

N

4

I simply don't have time or knowledge to change code to my liking.

Please explain why you wasted so much time trying to modify the HMC5883 library.

You can post a request on the Gigs & Collaborations section, but you might be asked to pay for the help.

5

I cannot change the code altogether so I was wondering if you had any experience with changing these registers.

6

I cannot change the code altogether

That is a joke, right?

7

I don't have time and do not know enough to change code. Please help instead of making fun of me

8

Hi Daniel,

It depends on which QMC5883L you're using.

After a somewhat torturous investigation, it turns out there's an A and B version of device, labelled DA5883 and DB5883 on the chip respectively.

The DA5883 is identical to the HMC5883L, except (and I kid you not) that the status register doesn't work. In this case it's possible to use a HMC5883L library, but it's necessary to comment out lines that poll the data ready (RDY) bit in the status register. Instead just read the data after a sample time delay of so many milliseconds in your sketch.

The DB5883 on the other hand is a completely different device and functions according the the QMC5883L datasheet. In this case, as jremington suggests just use a QMC5883L library instead.

It's rather frustrating, as these changes are completely undocumented and have caused a good deal of confusion for those of us using this device.

9

Thank you for your advice.

Daniel