In order to detect harsh acceleration, braking, and cornering events, the accelerometer must run continuously so that it can auto-orientate (figure out why way is down —  as gravity impacts the forces seen) itself and additionally self-calibrate. 

Given the power draw of the accelerometer, this is impractical to implement on a battery-powered device — so it is limited to the powered device range. These devices can be configured to send alerts when harsh events, accidents, or vehicle rollovers are detected. If vehicle rollover alerts are required, a powered device should be selected for the application.

Use cases:

  • Driver behavior monitoring
  • Safety and compliance
  • Fleet management

High-G Event Detection

This feature is designed around detecting where and when an impact has occurred to a device in transit. This will help in determining where damage may have been sustained. When enabled, this feature draws slightly more battery than if disabled. It will simply log a record (and upload if configured) any events that exceed a set force threshold. The minimum threshold is 1.5G and maximum is 6G (along any axis). 

Use cases:

  • Asset abuse or misuse monitoring

Tip Detection 

The Tip Detection feature allows you to define a range of angles that constitute a ‘tipped’ state. Every time the device enters this range, it will set a digital input, and increment an analog counter. It can also optionally log a record, perform a GPS fix, upload data, or scan for Bluetooth tags. 

Accelerometer event detection and use cases by Digital Matter

Use cases:

  • Detecting emptying of containers like skip bins
  • Tamper detection —  when the angle changes the device may have been removed from an asset
  • Detecting if the equipment has been knocked over.

This feature is not suitable for detecting a vehicle rollover, for a few reasons:

  • It has no auto-orientation function, so must be installed in the correct orientation to function. 
  • It only supports a single roll axis —  so rollover can easily be missed. 
  • Enabling this feature uses extra power while the device is on the move, for the duration of movement, which will result in potentially unsatisfactory battery life on a constantly moving vehicle.

Rotation Counting

This feature keeps a count of the number of rotations of the device about the Z axis. 

Use case:

  • Detecting the uncoiling of cable drums.

Tilt

This feature is available on the Guppy LoRaWAN — and will trigger an uplink once a pre-defined threshold. 

Guppy LoRaWAN | RestoTracker

Use cases:

  • Detecting when signs, fence posts, etc. have fallen over.

Hardware

Most of the devices by the Digital Matter are fitted with a 3D accelerometer, which is used to provide a variety of features. Many of the features are quite similar, but they have key differences which make them suitable for certain applications, and less suitable for others. 

Features per device

DeviceAccident and Rollover Detection + Harsh EventsHigh-G Event DetectionTip Detection and Rotation CountingTilt 
Bolt
Dart2
G120
G62
Oyster2
Remora2
Yabby GPS – Cellular
Yabby WiFi – Cellular
Guppy LoRaWAN