I was wondering, if there is a way to use IPhone as an HID device, with some other device like PS3. I checked out the Bluetooth specification and IOS Devices do support HID Profile. So I thought it would be easy to pair my iPhone using passkey mechanism and should be able to start using my iPhone as keyboard or mouse without much hassle. But I found very soon that this assumption is naive and I need to develop custom solution.
I was initially thinking about using GameKit framework, but I think it only works between two compatible IOS Devices. If I want to extend this capability, then I have to use iPhone External Accessory API .In my analysis, I also found that iPhone will only communicate and pair with devices that are licensed by Apple. (Made for iPhone\iPod program). Does it mean that, if I want to use iPhone with another device, I need to get that device approved by Apple. ( Which will not surprise me one bit). Also if someone could point me to more detailed documentation on this, that will also be helpful.( What is an MFI developer board ??)
I do not want a solution that needs me to jailbreak an iPhone. (or any solution that will disqualify my app by Apple).
So to summarize:
1- Please validate my findings, correct them if they are wrong?
2a- How does External Accessory API Work? b- Can I use this to connect to third party accessories ? (or is this only for accessory developers).
3- Or is there a better solution without using External Accessory API?
Please provide supportive documentation or link if you can. Thank You.
You are unlikely to get on the External accessory program from apple unless you are a big company ( you can try, but I have read this a number of places) . iPhones use a proprietary Bluetooth interface that and hardware must also implement this interface, so not much chance of getting it to connect to any other hardware directly.
Most apps like this (Remote Mouse) for example, connect to your wifi network, and have another application installed on your computer. The iphone can then talk to this application over the wi-fi network, but not bluetooth. I would suggest that the only way I can see this would be possible to to create the server app that you install on a computer on the wi-fi network that then in turn controls the 3rd party device if there is an API that you can use from the desktop app to control the 3rd party device.
This is just what I have found when I researched about this for making an app for iPhone to control a bluetooth watch. I had to jailbreak in the end to replace the bluetooth stack on the iPhone with one that could connect to any hardware device. Not limited by apple.
来源：https://stackoverflow.com/questions/6071516/iphone-bluetooth-connectivity-to-non-ios-devices