How does a remote shutter for camera work on Android/iOS?

Question

I've recently ran across a remote shutter for in-built camera app using bluetooth on Android/iOS.

Here's an example link of the product that I found: Link (Not here to advertise, but to simply understand technology/mechanism behind it)

As far as I know, it is not possible to send remote commands to the in-built camera apps since there is really no way for the in-app camera apps to handle the remote commands.

However, the above video shows that such remote control is achieved using the bluetooth remote shutter. I noticed no external app needs to be installed to use such a remote shutter device. Is the device simply sending a touch event action to the phone?

I guess my real question is, how would such a remote device send 'take photo' command to the existing in-built camera apps?

Thanks,

Solution 1

The selfie stick remotes are essentially tiny Bluetooth keyboards with just two keys. One is the "Volume Up" key to trigger iOS' native Camera shutter and the other key is "Enter" to trigger Android.

Solution 2

When the camera app is running, both Android and apple utilize the volume up button to signal the shutter event.

With this in mind, all an external device needs to do is trigger the same volume up event which in turn triggers the shutter event.

This then allows for a remote shutter button whether the button is plugged into the audio/mic port, or connected via bluetooth.

The audio mic port may be different between android and iphone. I plugged an external camera button into my android and rather than it triggering the volume up event, it triggered the back button in the mp3 player.

Hope this helps you out.

Comments

[Thinker]

So if you want to capture shutter in an iOS app, use the code in this SO answer: stackoverflow.com/a/36081853/59913