Connect a MMC5603 Triple-axis Magnetometer to an ESP32

Parts Required

You can connect to the sensor using Dupont style jumper wire.

Name	Link
ESP32		Aliexpress link Amazon Ebay
MMC5603		Aliexpress link ebay link
Connecting cables		Aliexpress link Amazon Ebay

Schematic/Connection

I used 3.3v from the ESP32 – and I also use the stemma/qwic connector

Code Example

I installed the Adafruit library using the Arduino ide which also installed the dependency library

Click the Manage Libraries … menu item, search for MMC56x3, and select the Adafruit_MMC56x3 library

If asked about dependencies, click on the “Install all” option

If the Dependencies window does appear, you already have the required dependencies installed.

If the dependencies are already installed, make sure that you have the latest ones installed using the Arduino Library Manager

This is the magsensor example – there are a few examples

#include <Adafruit_MMC56x3.h>

/* Assign a unique ID to this sensor at the same time */
Adafruit_MMC5603 mmc = 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 Test");
  Serial.println("");

  /* Initialise the sensor */
  if (!mmc.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);
  }

  /* Display some basic information on this sensor */
  mmc.printSensorDetails();
}

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

  // Display the results (magnetic vector values are in micro-Tesla (uT))
  Serial.print("X: ");
  Serial.print(event.magnetic.x);
  Serial.print("  ");
  Serial.print("Y: ");
  Serial.print(event.magnetic.y);
  Serial.print("  ");
  Serial.print("Z: ");
  Serial.print(event.magnetic.z);
  Serial.print("  ");
  Serial.println("uT");

  // Read and display temperature
  float temp_c = mmc.readTemperature();
  Serial.print("Temp: "); 
  Serial.print(temp_c); 
  Serial.println(" *C");
  // Delay before the next sample
  delay(1000);
}

Here is  an example of what I saw in the serial monitor window – you may see some different results

X: -3276.80 Y: -3276.80 Z: -3276.80 uT
Temp: 21.00 *C
X: -3276.80 Y: -3276.80 Z: -3276.80 uT
Temp: 25.00 *C
X: -3276.80 Y: -3276.80 Z: -3276.80 uT
Temp: 25.80 *C

This is the compass example – this would be good with one of those round LCD displays – a clue to a future project

#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);
}

The output of this example was this, I moved the sensor around

Compass Heading: 279.68
Compass Heading: 313.03
Compass Heading: 290.95
Compass Heading: 344.84
Compass Heading: 294.77

Links

https://media.digikey.com/pdf/Data%20Sheets/MEMSIC%20PDFs/MMC5603NJ_RevB_7-12-18.pdf