Keep display on when the proximity sensor is covered

I want to intercept the proximity sensor without turning off the display.

I know by the documentation that I have two Bool variables:

  • No such module … in Xcode
  • Reading raw bytes from an Aztec barcode via AVMetadataMachineReadableCodeObject yields unexpected result
  • Changing Data in a Plist
  • AVFoundation - How to control exposure
  • How do I automatically load the keyboard (iOS SDK)?
  • IAP fails after release, but no in development stage
  • proximityMonitoringEnabled

    and this code

    [UIDevice currentDevice].proximityMonitoringEnabled = YES;

    When the proximity sensor detects something it turns off the display, same way it does when you’re holding the phone to your ear when on a phone call.

    How do I keep the display on when the proximity sensor is covered?

    5 Solutions Collect From Internet About “Keep display on when the proximity sensor is covered”

    After reading different forums on the topic, its currently not possible for us in the public api to prevent the iPhone screen from going black when the proximity sensor is covered. The only thing you can do with the sensor is tell when its covered or not thru the notification center but again you can’t control its natural behavior (When it dims/blacks out the screen).

    Apple’s documentation notes that “Not all iPhone OS devices have proximity sensors.” To determine if the device your app is running supports proximity monitoring, set the proximityMonitoringEnabled property to YES, then check its value:

    UIDevice *device = [UIDevice currentDevice];
    [device setProximityMonitoringEnabled:YES];
    if (device.proximityMonitoringEnabled == YES) {
        [[NSNotificationCenter defaultCenter] addObserver:self 
    - (void) proximityChanged:(NSNotification *)notification {
        UIDevice *device = [notification object];
        NSLog(@"In proximity: %i", device.proximityState);


    Will help to detect current state of sensor.

    Public API that allows screen dim:

    [UIScreen mainScreen].wantsSoftwareDimming = YES;
    [UIScreen mainScreen].brightness = $your_brightness_value;

    Found here: Change to wantsSoftwareDimming in iOS 6?

    Although there is no public API to do this, you can hook into IOKit‘s IOHIDEventSystem and listen for screen dimming notifications:

    // Create and open an event system.
    IOHIDEventSystemRef system = IOHIDEventSystemCreate(NULL);
    // Set the PrimaryUsagePage and PrimaryUsage that the AppleProxShim service uses
    int page = 65280;
    int usage = 8;
    // Create a dictionary to match the service with
    CFStringRef keys[2];
    CFNumberRef nums[2];
    keys[0] = CFStringCreateWithCString(0, "PrimaryUsagePage", 0);
    keys[1] = CFStringCreateWithCString(0, "PrimaryUsage", 0);
    nums[0] = CFNumberCreate(0, kCFNumberSInt32Type, &page);
    nums[1] = CFNumberCreate(0, kCFNumberSInt32Type, &usage);
    CFDictionaryRef dict = CFDictionaryCreate(0, (const void**)keys, (const void**)nums, 2, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
    // Get the total of matching services with the above criteria
    CFArrayRef srvs = (CFArrayRef)IOHIDEventSystemCopyMatchingServices(system, dict, 0, 0, 0, 0);
    // Get the service
    IOHIDServiceRef serv = (IOHIDServiceRef)CFArrayGetValueAtIndex(srvs, 0);
    int interval = 1 ;
    // Set an interval of 1 , to activate the sensor  
    IOHIDServiceSetProperty((IOHIDServiceRef)serv, CFSTR("ReportInterval"), CFNumberCreate(0, kCFNumberSInt32Type, &interval));
    // add your event handler
    IOHIDEventSystemOpen(system, handle_event, NULL, NULL, NULL);
    int defaultInterval = 0;
    IOHIDServiceSetProperty((IOHIDServiceRef)serv, CFSTR("ReportInterval"), CFNumberCreate(0, kCFNumberSInt32Type, &defaultInterval));
    // close handles and release the IOHIDEventSystemRef
    IOHIDEventSystemClose(system, NULL);

    Your event handler function pointer will look something like this:

    void handle_event(void* target, void* refcon, IOHIDServiceRef service, IOHIDEventRef event) {
        if (IOHIDEventGetType(event) == kIOHIDEventTypeProximity) { // Proximity Event Received
            // not necessary, but if you want the value from the sensor, get it from IOHIDEventGetIntegerValue
            int proximityValue = IOHIDEventGetIntegerValue(event, (IOHIDEventField)kIOHIDEventFieldProximityDetectionMask); // Get the value of the ProximityChanged Field (0 or 64)
            // Call dimScreen with the boolean NO
            int (*SBSSpringBoardServerPort)() = (int (*)())dlsym(RTLD_DEFAULT, "SBSSpringBoardServerPort");
            int port = SBSSpringBoardServerPort(); 
            void (*_SBDimScreen)(int _port,BOOL shouldDim) = (void (*)(int _port,BOOL shouldDim))dlsym(RTLD_DEFAULT, "SBDimScreen");
            // This is where the logic to dim the screen based on the sensor value would go.  In this case, I'm hardcoding NO instead of the value of proximityValue from above
            // BOOL dim = proximityValue == 0 ? NO : YES;
            _SBDimScreen(port, NO); 

    Calling _SBDimScreen may not even be necessary, as having an empty function pointer may stop all proximity sensor events.

    Code modified from the command line tool example on the AppleProxShim page on the iPhoneDevWiki.

    Use the following API to enable/disable the proximity sensor.

    [UIDevice currentDevice].proximityMonitoringEnabled = NO; // Disables the Proximity Sensor and won't turnoff the display when sensor covered
    [UIDevice currentDevice].proximityMonitoringEnabled = YES; // Enables the Proximity Sensor and will turnoff the display when sensor covered

    Not all iOS devices have proximity sensors. To determine if proximity monitoring is available, attempt to enable it. If the value of the proximityMonitoringEnabled property remains NO, proximity monitoring is not available.

    fo swift / iOS 10 / xcode 8.2

    UIDevice.current.isProximityMonitoringEnabled = true/false..