Alright, I have searched high and low and been unable to find a simple answer to this question. It must be possible for the nrf51 to launch Siri on an iPhone, I have seen product using it mention this as a feature. But I cannot find out the way to do it.
Anyone know how? Is it a special HID media key? Or some other profile? All I want to do is launch Siri, not interact with it, so the equivalent of holding the iPhone home button.
The only other thought I had last night was the chipset was dual mode (I've almost forgotten about good old BR/EDR Bluetooth) and thus supports both. If you're able to sniff the LE connection all the way through pairing and keep it going, you'll at least be able to see what the BTLE bit does when you hit the siri button.
The point remains that this will not be specific to the Bluetooth chipset in the device - it will have to be relying on some standard service/API/facility in iOS
Well there is one - the HFP extension is documented for this - however HFP isn't available over BLE as far as I know, only BR/EDR. Since the device looks like it's BLE, the only other option I could come up with is that it's both, it does most work over BLE and uses BR/EDR for HFP or other services which require it.
Unless there's a BLE-available service on iOS which enables Siri, and I've never found one, a dual mode chipset is all I could come up with for being low energy and also able to support HFP
Well, the device arrives today and so we can hopefully figure out the answer! My money says it is some undocumented HID key that can trigger it, many keyboards seem to be able to do the same. I did try some of the keys labeled Home, but couldn't get them to work, so not sure what it is exactly.
Ok, I got the device and the results are... inconclusive.
This device does not use Bluetooth LE, it is most certainly a classic Bluetooth device. The chipset inside is this: www.broadcom.com/.../bcm20730
Now, I am still not convinced that the nrf51 won't work. This is a HID device, so it should be possible to mimic this with HID over GATT. When my iPhone first detected this button, for the briefest of moments it showed up as a generic keyboard.
I will keep trying different HID keys, that must be the answer...