Odyssey Personality – Motion Detection

Introduction

This personality allows a user to read the forces acting on the Odyssey board in all three directions (X, Y, Z) including gravity. It also displays motion status every second with two states: Motion detected and Motion stopped.

How To Use

Press individual buttons for readings of forces on X, Y and Z axes. Even holding the Odyssey still on a level desk will show readings from the force of gravity (shows force of 1G in Z direction). The signed decimal reading will generally show +/- 72 for +/- 1G, so sitting level on a surface, X and Y will be approximately zero and the Z reading will be approximately 72. Hold the Odyssey in different positions and press the buttons to see the different readings as gravity applies to the different directions (axes).

Motion detection is given by the status register reading. The status register is shown in the autonomous field at the bottom of the display, updated every second. Due to the status register bit configuration:

1 = No motion, and 65 = Motion detected – over threshold (decimal readings).

Users can copy and edit the personality to change ranges, thresholds, etc. through register settings.

How It Works

The ADXL362 is an ultralow power, 3-axis MEMS accelerometer that consumes less than 2 μA at a 100 Hz output data rate and 270 nA when in motion triggered wake-up mode. Unlike accelerometers that use power duty cycling to achieve low power consumption, the ADXL362 does not alias input signals by under-sampling; it samples the full bandwidth of the sensor at all data rates. The ADXL362 has an adjustable sleep/wake mode for motion activation. Thresholds, granularity, modes, etc. are all setup in registers with a SPI bus interface. The personality uses SPI reads and writes for setup and access.

More Info

Requires minimum firmware v1.1. If needed, see the software download page.

• Analog Devices ADXL362 sensor product information [click here]