The MWL01 Beacon is an AoA beacon which means it advertises a constant tone extension (CTS) for angle of arrival detection. An accelerometer detects the degree of movement and adjusts the advertising across three levels between 100ms (fast) -> 250ms (normal) -> 4s (slow) to save battery life. The battery level is provided in the advertising data. Double clicking the button changes the advertising, for example, for SOS notification.
Here are some observations that aren’t immediately obvious in the documentation:
While AoA is Bluetooth 5.x, It actually advertises Bluetooth 4.1 rather than 5.x. This makes it suitable for non-AoA applications where it can be detected by non AoA Bluetooth 4.1 receivers. It’s particularly suited for asset tracking because it increases the period between advertising, when not moving, to significantly save battery.
You might think the change to 4s advertising isn’t working. Be patient. It takes 5 minutes of normal advertising before it switches to slow advertising. Note that it also takes 5 seconds to go from fast advertising to normal advertising. While the advertising rates can be changed, the times to transition can’t be changed.
The beacon that is supplied with the AoA kit is different to that supplied separately. The kit’s MWL01 is fixed to 100ms advertising and can’t be changed. This is because it much easier to evaluate AoA and develop software when the advertising is consistent over time. The kit MWL01 can be upgraded, if necessary, to support the changing advertising period. However, we recommend you keep them as 100ms advertising beacons for ease of testing.
The ‘Location Finding’ flag in the AoA advertising is actually an indication of the double button press rather than anything to do with direction finding. This flag stays on for a minute and the blue led flashes during this time. Again, the double button press is only available on the non-kit beacon.
The battery level isn’t in the AoA data advertising. The beacon advertises a second connectable broadcast frame that includes the MAC address and battery level every 1s, 1s and 4s in the fast, normal, and slow modes respectively. These times can’t be changed.
Unfortunately, Minew are stipulating that the settings and firmware upgrade are only available to people who have signed an NDA with Minew or BeaconZone if you purchased the beacons from us.
The video showcases the beacon, shows it in use, demonstrates how to update the output power settings and update the firmware. Please note that the MWL01 only provides direction finding AoA functionality in collaboration with the G2 AoA Kit.
Depending on the beacon, this can be setup either to only advertise when the key is pressed (button triggered) or advertising all the time and the advertising changes. The former is better for longer battery life while the latter is better when you need to continuously know the beacon is working.
Advertising can be detected:
In apps using standard Apple and Android Bluetooth APIs
A few beacons allow a keypress to be notified to a connected application. Apps on iOS and Android, applications on single board computers and desktops/laptops can connect to a Bluetooth Service Characteristic to be notified when there’s a key press. Connection suspends advertising and prevents the button device from being seen/connected to from other devices.
Long pressing OFF does not cause the beacon to turn off but instead puts the beacon into ‘SOS’ mode where the configured advertising is stopped and the ‘SOS’ can be detected in the configuration app or your custom app and the ‘SOS’ state cancelled.