MMC56x3 compass grief

Support
1

I’m hoping to build a small portable compass ideally with at least an OLED showing the heading or even something exotic like this:https://www.instructables.com/Arduino-Analog-Digital-Compass-With-HMC5883L-Senso/ (yes I know its for a different sensor but the one I bought from eB*y was a fake so I thought I’d ‘treat myself’ to a proper one from Pimoroni.
Using the example code ‘compass’ from the Adafruit_MMC56x3.h library it compiles and uploads OK. But I get the following regardless of how I wave the sensor around (in X,Y & Z).

Adafruit_MMC5603 Magnetometer Compass

Compass Heading: 96.35
Compass Heading: 96.15
Compass Heading: 96.19
Compass Heading: 96.17
Compass Heading: 95.31
Compass Heading: 89.13
Compass Heading: 90.86
Compass Heading: 89.69
Compass Heading: 94.09
Compass Heading: 95.43
Compass Heading: 96.17
Compass Heading: 89.95

Which leaves me puzzled… Ultimately as its using I2C I’d distance limited (its going up an aerial mast) so a serial link down to another Nano with an OLED serial display of the numbers would work for me. Links to any functioning compass code gratefully received…
Gareth

2

Circuit python or Micro Python?
Posting your code would help. Click the Preformatted Text button </> to wrap it in code tags.

3

Here is the listing - untouched from the example…

#include <Adafruit_MMC56x3.h>

/* Assign a unique ID to this sensor at the same time */
Adafruit_MMC5603 mag = Adafruit_MMC5603(12345);

void setup(void) {
  Serial.begin(115200);
  while (!Serial)
    delay(10); // will pause Zero, Leonardo, etc until serial console opens

  Serial.println("Adafruit_MMC5603 Magnetometer Compass");
  Serial.println("");

  /* Initialise the sensor */
  if (!mag.begin(MMC56X3_DEFAULT_ADDRESS, &Wire)) {  // I2C mode
    /* There was a problem detecting the MMC5603 ... check your connections */
    Serial.println("Ooops, no MMC5603 detected ... Check your wiring!");
    while (1) delay(10);
  }
}

void loop(void)
{
  /* Get a new sensor event */
  sensors_event_t event;
  mag.getEvent(&event);

  float Pi = 3.14159;

  // Calculate the angle of the vector y,x
  float heading = (atan2(event.magnetic.y,event.magnetic.x) * 180) / Pi;

  // Normalize to 0-360
  if (heading < 0)
  {
    heading = 360 + heading;
  }
  Serial.print("Compass Heading: ");
  Serial.println(heading);
  delay(500);
}
I can't see it should do anything iother than oputput 0-359 into the serial monitor....
Gareth
4

Ok, looks like Arduino code? I have no Arduino experience. =(

5

I’d add some debug to print out the x/y (and possibly z) values, which might clarify if there’s a problem with the data or if the sensor is in an unexpected orientation :-)