I may have experimented with them a bit. But I was doing it from a read-the-button perspective, not the alarm perspective. They were easy enough to figure out. I was massively disappointed to discover that the button state wasn't part of the advertising broadcast, and that you actually had to connect to the devices to properly read the button. Most of them you could read by inference because when the button was pressed, there would be a flurry of broadcasts.
There is an app called nRF Connect, that lets you connect to BLE devices and explore their attributes/characteristics.
Range might be an issue. One of my early trial applications was as a feline locator, but unfortunately those dang cats go more than 50 metres. But if you know *roughly* where the drone went down, you could use BLE to hunt it down by circling the area and listening for the advertising broadcasts, which are emitted once per second.
Uh, maybe that 50 metres depends on the phone and/or the brand of iTag. I just tried this one outside, line-of-sight, and at 18 metres it was -91 dB and usable (I could activate the beep) but at 24 metres it disappeared off the scanner. I put a new battery in it (measured 3.1 V) but same deal.
Depending on the situation, it might be an option to make it beep all the time? Presumably the battery in the tracker would last longer than the battery in the drone?
The idea is that you know roughly where it went down but small drones are very difficult to see in long grass or trees! and you want to avoid treading on it. So once your phone can see the tracker you activate the alarm. Also I see that nRF Connect appears to be able to graph the the RSSSI which might also help in seeing whether you are moving in the right direction.
Lol I discovered that out on the street tonight too, but it was unusable because turns out my neighbors are leaking Bluetooth all over the place. My phone nearly blew up.
which might also help in seeing whether you are moving in the right direction.
I saw that but it needs WORK to do it, the nRF Connect app seems to have everything I need already implemented so no need to reinvent the wheel for what will only be occasional (perhaps never!) use. Just waiting for the delivery of an iTag now!