BMM150

In this article we look at the BMM150 digital geomagnetic sensor

BMM150 is a low power and low noise 3-axis digital geomagnetic sensor to be used in compass applications. The 12-pin wafer level chip scale package (WLCSP) with a footprint of 1.56 x 1.56 mm² and 0.60 mm height provides highest design flexibility to the developer of mobile devices. Applications like virtual reality or gaming on mobile devices such as mobile phones, tablet PCs or portable media players require 9-axis inertial sensing including magnetic heading information. Due to the stable performance over a large temperature range, the BMM150 is also especially suited for supporting drones in accurate heading.

BMM150 can be used with an inertial measurement unit (IMU) consisting of a 3-axis accelerometer and a 3-axis gyroscope like Bosch Sensortec’s BMI055.

Features

Parts Required

Name	Link
NUCLEO-L496ZG	1/PCS LOT NUCLEO-L496ZG Nucleo development board STM32L4 series development board
BMM150	BMM150 Geomagnetic Sensor Breakout Board
Connecting wire	Free shipping Dupont line 120pcs 20cm male to male + male to female and female to female jumper wire

Schematic/Connection

Code Example

This uses the library from https://github.com/Seeed-Studio/Grove_3_Axis_Compass_V2.0_BMM150

#include <Arduino.h>
#include <Wire.h>
// libraries
#include "bmm150.h"
#include "bmm150_defs.h"

BMM150 bmm = BMM150();

void setup()
{
Serial.begin(9600);

if(bmm.initialize() == BMM150_E_ID_NOT_CONFORM) {
Serial.println("Chip ID can not read!");
while(1);
} else {
Serial.println("Initialize done!");
}

}

void loop()
{
bmm150_mag_data value;
bmm.read_mag_data();

value.x = bmm.raw_mag_data.raw_datax;
value.y = bmm.raw_mag_data.raw_datay;
value.z = bmm.raw_mag_data.raw_dataz;

float xyHeading = atan2(value.x, value.y);
float zxHeading = atan2(value.z, value.x);
float heading = xyHeading;

if(heading < 0)
heading += 2*PI;
if(heading > 2*PI)
heading -= 2*PI;
float headingDegrees = heading * 180/M_PI;
float xyHeadingDegrees = xyHeading * 180 / M_PI;
float zxHeadingDegrees = zxHeading * 180 / M_PI;

Serial.print("Heading: ");
Serial.println(headingDegrees);

delay(100);
}

Output

Open the serial monitor and you should see something like this

Heading: 336.04
Heading: 343.22
Heading: 4.57
Heading: 16.11
Heading: 52.82
Heading: 119.54
Heading: 174.52
Heading: 183.81
Heading: 190.16

Links

https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMM150-DS001.pdf

https://github.com/BoschSensortec/BMM150-Sensor-API