Use iPhone's Proximity Sensor

Question

Created Aug ’22

Replies 3

Boosts 0

Views 5.8k

Participants 5

Hi ✋ I'm trying to build an app with SwiftUI, and I'm completely new to coding. I want to use iPhone's proximity sensor as a feature in my app.

This is not what I actually want, but to make it simple:

Say there is a number shown on the screen. Whenever I cover the iPhone's proximity sensor with my hand, the number is increased by one. theNumber += 1

 import SwiftUI
 
struct ContentView: View {
    @State private var theNumber: Int = 0
 
    var body: some View {
        Text("\(theNumber)")
    }
}

Boost

Answer 1

BabyJ OP

Aug ’22

Accepted Answer

You can retrieve the proximityState value from the current UIDevice and detect when it changes. You need to enable proximity monitoring first and I suggest doing that in your main App struct.

 // in main App struct
init() {
    UIDevice.current.isProximityMonitoringEnabled = true
}

 struct ContentView: View {
    @State private var theNumber = 0
 
    var body: some View {
        Text("\(theNumber)")
            .onReceive(NotificationCenter.default.publisher(for: UIDevice.proximityStateDidChangeNotification)) { _ in
                if UIDevice.current.proximityState {
                    // sensor is close to user
                    // true is "near", false is "far"
 
                    theNumber += 1
                }
            }
    }
}

‎

Things to Note

The sensor detects objects up to 10 cm away.
When the sensor detects an object that is close, the screen turns off.
There is no single point where the proximity state switches between "near" and "far", but instead a buffer range.
When the state is "far", the object must be up to 5 cm from the sensor in order to change the state to "near".
When the state is "near", the object must be at least 10 cm from the sensor in order to change the state to "far".

1

Answer 2

Hdhjhc OP

Dec ’22

Thanks for this

0

Answer 3

Davu OP

Apr ’23

I copied this code and ran it on my iPhone 13. The number does not change. I did confirm that my sensor was working by calling someone to see if my screen turns off.

0

	import SwiftUI

	struct ContentView: View {
	@State private var theNumber: Int = 0

	var body: some View {
	Text("\(theNumber)")
	}
	}

	// in main App struct
	init() {
	UIDevice.current.isProximityMonitoringEnabled = true
	}

	struct ContentView: View {
	@State private var theNumber = 0

	var body: some View {
	Text("\(theNumber)")
	.onReceive(NotificationCenter.default.publisher(for: UIDevice.proximityStateDidChangeNotification)) { _ in
	if UIDevice.current.proximityState {
	// sensor is close to user
	// true is "near", false is "far"

	theNumber += 1
	}
	}
	}
	}