TWS Case Opening / Closing

and Earbuds Case-in / Case-out Detection

Tri-axis Magnetic Sensors

In this section, we explain, by using the Tri-axis Magnetic Smart Switch, how to simultaneously detect the opening / closing of the True Wireless Stereo case that is used primarily for triggering Bluetooth pairing / unpairing between the Earbuds and smartphone and case-in / case-out of the right and left Earbuds.

Applications overview

Detection of the open / close status of the True Wireless Stereo case and detection of whether the right and left Earbuds are housed in the case are achieved by using a Tri-axis Magnetic Smart Switch and existing magnets. This technique is used as a trigger for smooth Bluetooth pairing / unpairing between a True Wireless Stereo case or Earbuds and a smartphone.

Applications overview

Technology overview

Tri-axis Magnetic Smart Switch mounted on the case body acquires the magnetic field generated by the magnets on the lid of the True Wireless Stereo case and the magnets built into the Earbuds. Whenever the lid is opened or closed or Earbuds are in / out case, the magnetic field that is applied to the Tri-axis Magnetic Switch changes. The status of the Earbuds can be checked by detecting and analyzing the change. 

Technology overview

Advantage of this solution

Advantages of tri-axis Magnetic Smart Switch in this application are:

  • One sensor and existing magnets configurations enable simultaneous detection of "case lid open / close" and "earphone case in/out"
  • Tri-axis magnetic field sensing and wide measuring range provide greater flexibility in sensor-and magnet-layout
  • Low current consumption design using variable magnetic field threshold function is possible
Multiple state detection Multiple state detection
Flexible layout Flexible layout
Power save (@100Hz ODR) Power save (@100Hz ODR)

Concept demonstration

  • This video demonstrates how the opening and closing of the case and Earbuds case-in / case-out status are detected by using an actual True Wireless Stereo housing and a probe board mounted with a Tri-axis Magnetic Smart Switch.
  • AKM provides magnetic simulation suitable for your True Wireless Stereo (TWS) housing. If you are interested in TWS demonstration, please make an inquiry by using the form in the Inquiry page in the following link.