Magnetometer

Periodically read magnetometer sensor data and display on a ZentriOS terminal.

• SDK directory: apps/sensors/magnetometer
• Zentri App Store: ZENTRI-SEMAGNETO

API Features Demonstrated

• Event Handling API
  • zn_event_register_periodic
• Sensor Library
  • sensor_init
  • sensor_has_new_data
  • sensor_get_data

Platforms

This app works on:

• AMW004 - Zentri Mackerel evaluation board - additional hardware required
• AMW106 - Zentri Moray evaluation board - additional hardware required
• NXP-SCCK - NXP Secure Cloud Connectivity Kit - additional hardware required

Requirements and Prerequisites

This app requires a ZentriOS device, such as an AMWx06-E03 (Moray), connected via the I2C interface to a MPU-9250 gyroscope sensor from Invensense.

Description

Periodically read magnetometer sensor data and display on a ZentriOS terminal.

Usage Instructions

See Connecting a Zentri AMW106 to an InvenSense MPU-9250.

Open a ZentriOS serial terminal to the device. See Getting Started, Opening a ZentriOS Terminal.

Build, download and run the app. It displays a message similar to the following on the ZentriOS terminal:

Starting Magnetometer App
Initialisation successful!
Getting data....
X: -27 uT
Y: -1 uT
Z: -90 uT
Getting data....
X: -28 uT
Y: -1 uT
Z: -89 uT
Getting data....
X: -28 uT
Y: -2 uT
Z: -90 uT

where X/Y/Z values reflect periodic sensor readings.

Implementation

zn_app_init()

• The call to sensor_init configures the sensor.
• The call to zn_event_register_periodic registers the periodic event read_magn_data.

read_mag_data()

• The call to sensor_has_new_data determines whether new data is ready.
• If data is available, sensor_get_data reads the data. The data is formatted and logged to the ZentriOS terminal.

Source

See:

• main.c