Added Ambilight-clone functionality

CaseLights.ino

  * The UV command turns the UV lights on or off (s can be 0 or 1).
  */
 
-#define DEBUG
+//#define DEBUG
 
 enum LoopState {
   LOOP_IDLE,

CaseLights.xcodeproj/project.pbxproj

 		E9109B111C2AACF400726111 /* SystemInfoKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = E9109B0B1C2AAC1B00726111 /* SystemInfoKit.framework */; };
 		E9109B151C2AAEFD00726111 /* SystemInfoKit.framework in CopyFiles */ = {isa = PBXBuildFile; fileRef = E9109B0B1C2AAC1B00726111 /* SystemInfoKit.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		E9109B191C2AAFE100726111 /* GPUStats.m in Sources */ = {isa = PBXBuildFile; fileRef = E9109B181C2AAFE100726111 /* GPUStats.m */; };
+		E9640E8A1C30511B0081D46C /* Screenshot.m in Sources */ = {isa = PBXBuildFile; fileRef = E9640E891C30511B0081D46C /* Screenshot.m */; };
 		E9AB18011C29F8CD00BF3C51 /* Serial.m in Sources */ = {isa = PBXBuildFile; fileRef = E9AB18001C29F8CD00BF3C51 /* Serial.m */; };
 		E9F13E031C28B3D3004C6B95 /* AppDelegate.m in Sources */ = {isa = PBXBuildFile; fileRef = E9F13E021C28B3D3004C6B95 /* AppDelegate.m */; };
 		E9F13E061C28B3D3004C6B95 /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = E9F13E051C28B3D3004C6B95 /* main.m */; };
 		E9109B051C2AAC1B00726111 /* SystemInfoKit.xcodeproj */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.pb-project"; name = SystemInfoKit.xcodeproj; path = JSystemInfoKit/SystemInfoKit.xcodeproj; sourceTree = "<group>"; };
 		E9109B171C2AAFE100726111 /* GPUStats.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = GPUStats.h; path = CaseLights/GPUStats.h; sourceTree = "<group>"; };
 		E9109B181C2AAFE100726111 /* GPUStats.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = GPUStats.m; path = CaseLights/GPUStats.m; sourceTree = "<group>"; };
+		E9640E881C30511B0081D46C /* Screenshot.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = Screenshot.h; path = CaseLights/Screenshot.h; sourceTree = "<group>"; };
+		E9640E891C30511B0081D46C /* Screenshot.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = Screenshot.m; path = CaseLights/Screenshot.m; sourceTree = "<group>"; };
 		E9AB17FF1C29F8CD00BF3C51 /* Serial.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = Serial.h; path = CaseLights/Serial.h; sourceTree = "<group>"; };
 		E9AB18001C29F8CD00BF3C51 /* Serial.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = Serial.m; path = CaseLights/Serial.m; sourceTree = "<group>"; };
 		E9F13DFE1C28B3D3004C6B95 /* CaseLights.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = CaseLights.app; sourceTree = BUILT_PRODUCTS_DIR; };
 			children = (
 				E9AB17FF1C29F8CD00BF3C51 /* Serial.h */,
 				E9AB18001C29F8CD00BF3C51 /* Serial.m */,
+				E9640E881C30511B0081D46C /* Screenshot.h */,
+				E9640E891C30511B0081D46C /* Screenshot.m */,
 				E9109B171C2AAFE100726111 /* GPUStats.h */,
 				E9109B181C2AAFE100726111 /* GPUStats.m */,
 			);
 			files = (
 				E9AB18011C29F8CD00BF3C51 /* Serial.m in Sources */,
 				E9109B191C2AAFE100726111 /* GPUStats.m in Sources */,
+				E9640E8A1C30511B0081D46C /* Screenshot.m in Sources */,
 				E9F13E061C28B3D3004C6B95 /* main.m in Sources */,
 				E9F13E031C28B3D3004C6B95 /* AppDelegate.m in Sources */,
 			);

CaseLights/AppDelegate.h

 @property (weak) IBOutlet NSMenu *menuColors;
 @property (weak) IBOutlet NSMenu *menuAnimations;
 @property (weak) IBOutlet NSMenu *menuVisualizations;
+@property (weak) IBOutlet NSMenuItem *menuItemDisplays;
+@property (weak) IBOutlet NSMenu *menuDisplays;
 @property (weak) IBOutlet NSMenu *menuPorts;
 
 @property (weak) IBOutlet NSMenuItem *buttonOff;
 @property (weak) IBOutlet NSMenuItem *brightnessLabel;
 @property (weak) IBOutlet NSMenuItem *buttonLights;
 
+- (void)clearDisplayUI;
+- (void)updateDisplayUI:(NSArray *)displayIDs;
+
 @end
 

CaseLights/AppDelegate.m

 #import "AppDelegate.h"
 #import "Serial.h"
 #import "GPUStats.h"
+#import "Screenshot.h"
 
 #import "SystemInfoKit/SystemInfoKit.h"
 
 
 @synthesize statusMenu, application;
 @synthesize menuColors, menuAnimations, menuVisualizations, menuPorts;
+@synthesize menuItemDisplays, menuDisplays;
 @synthesize buttonOff, buttonLights;
 @synthesize brightnessItem, brightnessSlider, brightnessLabel;
 @synthesize statusItem, statusImage;
         for (int i = 0; i < [ports count]; i++) {
             // Add Menu Item for this port
             NSMenuItem *item = [[NSMenuItem alloc] initWithTitle:[ports objectAtIndex:i] action:@selector(selectedSerialPort:) keyEquivalent:@""];
+            [item setTag:-1];
             [menuPorts addItem:item];
             
             // Set Enabled if it was used the last time
                     nil];
     for (NSString *key in [staticColors allKeys]) {
         NSMenuItem *item = [[NSMenuItem alloc] initWithTitle:key action:@selector(selectedVisualization:) keyEquivalent:@""];
+        [item setTag:-1];
         if ([key isEqualToString:lastMode]) {
             [self selectedVisualization:item];
         }
                                  nil];
     for (NSString *key in animationStrings) {
         NSMenuItem *item = [[NSMenuItem alloc] initWithTitle:key action:@selector(selectedVisualization:) keyEquivalent:@""];
+        [item setTag:-1];
         if ([key isEqualToString:lastMode]) {
             [self selectedVisualization:item];
         }
     
     // Add CPU Usage menu item
     NSMenuItem *cpuUsageItem = [[NSMenuItem alloc] initWithTitle:TEXT_CPU_USAGE action:@selector(selectedVisualization:) keyEquivalent:@""];
+    [cpuUsageItem setTag:-1];
     if ([lastMode isEqualToString:TEXT_CPU_USAGE]) {
         [self selectedVisualization:cpuUsageItem];
     }
     
     // Add Memory Usage item
     NSMenuItem *memoryUsageItem = [[NSMenuItem alloc] initWithTitle:TEXT_RAM_USAGE action:@selector(selectedVisualization:) keyEquivalent:@""];
+    [memoryUsageItem setTag:-1];
     if ([lastMode isEqualToString:TEXT_RAM_USAGE]) {
         [self selectedVisualization:memoryUsageItem];
     }
         NSLog(@"Error reading GPU information\n");
     } else {
         NSMenuItem *itemUsage = [[NSMenuItem alloc] initWithTitle:TEXT_GPU_USAGE action:@selector(selectedVisualization:) keyEquivalent:@""];
+        [itemUsage setTag:-1];
         if ([lastMode isEqualToString:TEXT_GPU_USAGE]) {
             [self selectedVisualization:itemUsage];
         }
         [menuVisualizations addItem:itemUsage];
         
         NSMenuItem *itemVRAM = [[NSMenuItem alloc] initWithTitle:TEXT_VRAM_USAGE action:@selector(selectedVisualization:) keyEquivalent:@""];
+        [itemVRAM setTag:-1];
         if ([lastMode isEqualToString:TEXT_VRAM_USAGE]) {
             [self selectedVisualization:itemVRAM];
         }
 
         if ([key isEqualToString:KEY_CPU_TEMPERATURE]) {
             NSMenuItem *item = [[NSMenuItem alloc] initWithTitle:TEXT_CPU_TEMPERATURE action:@selector(selectedVisualization:) keyEquivalent:@""];
+            [item setTag:-1];
             if ([lastMode isEqualToString:TEXT_CPU_TEMPERATURE]) {
                 [self selectedVisualization:item];
             }
         
         if ([key isEqualToString:KEY_GPU_TEMPERATURE]) {
             NSMenuItem *item = [[NSMenuItem alloc] initWithTitle:TEXT_GPU_TEMPERATURE action:@selector(selectedVisualization:) keyEquivalent:@""];
+            [item setTag:-1];
             if ([lastMode isEqualToString:TEXT_GPU_TEMPERATURE]) {
                 [self selectedVisualization:item];
             }
             [serial sendString:@"UV 0\n"];
         }
     }
+    
+    // List available displays and add menu items
+    [Screenshot init:self];
+    NSArray *displayIDs = [Screenshot listDisplays];
+    [self updateDisplayUI:displayIDs];
 }
 
 - (void)applicationWillTerminate:(NSNotification *)aNotification {
+    // Stop previous timer setting
+    if (animation != nil) {
+        [animation invalidate];
+        animation = nil;
+    }
+    
+    // Remove display callback
+    [Screenshot close:self];
+    
+    // Turn off all lights if possible
     if ([serial isOpen]) {
         [serial sendString:@"RGB 0 0 0\n"];
         [serial sendString:@"UV 0\n"];
     }
 }
 
+- (void)clearDisplayUI {
+    for (int i = 0; i < [menuDisplays numberOfItems]; i++) {
+        if ([[menuDisplays itemAtIndex:i] isEnabled] == YES) {
+            // A display configuration is currently selected. Disable the timer
+            if (animation != nil) {
+                [animation invalidate];
+                animation = nil;
+            }
+        }
+    }
+    [menuDisplays removeAllItems];
+    [menuItemDisplays setHidden:YES];
+}
+
+- (void)updateDisplayUI:(NSArray *)displayIDs {
+    if ([displayIDs count] > 0) {
+        NSUserDefaults *store = [NSUserDefaults standardUserDefaults];
+        NSString *lastMode = [store stringForKey:PREF_LED_MODE];
+        [menuItemDisplays setHidden:NO];
+        for (int i = 0; i < [displayIDs count]; i++) {
+            NSString *title = [Screenshot displayNameFromDisplayID:[displayIDs objectAtIndex:i]];
+            NSMenuItem *item = [[NSMenuItem alloc] initWithTitle:title
+                                                          action:@selector(selectedVisualization:)
+                                                   keyEquivalent:@""];
+            [item setTag:[[displayIDs objectAtIndex:i] integerValue]];
+            if ([title isEqualToString:lastMode]) {
+                [self selectedVisualization:item];
+            }
+            [menuDisplays addItem:item];
+        }
+    }
+}
+
 - (void)setLightsR:(unsigned char)r G:(unsigned char)g B:(unsigned char)b {
     if ([serial isOpen]) {
         unsigned char red = r * ([brightnessSlider floatValue] / 100.0);
     for (int i = 0; i < [ports count]; i++) {
         // Add Menu Item for this port
         NSMenuItem *item = [[NSMenuItem alloc] initWithTitle:[ports objectAtIndex:i] action:@selector(selectedSerialPort:) keyEquivalent:@""];
+        [item setTag:-1];
         [menuPorts addItem:item];
         
         // Mark it if it is currently open
             }
             [[menuVisualizations itemAtIndex:i] setState:NSOffState];
         }
+        for (int i = 0; i < [menuDisplays numberOfItems]; i++) {
+            if ([[menuDisplays itemAtIndex:i] state] == NSOnState) {
+                lastLEDMode = [menuDisplays itemAtIndex:i];
+            }
+            [[menuDisplays itemAtIndex:i] setState:NSOffState];
+        }
         
         // Turn on "off" menu item
         [sender setState:NSOnState];
     return YES;
 }
 
+- (void)displayVisualization:(NSMenuItem *)sender {
+    // Stop previous timer setting
+    if (animation != nil) {
+        [animation invalidate];
+        animation = nil;
+    }
+    
+    // Schedule next invocation for this animation...
+    animation = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(visualizeDisplay:) userInfo:[NSNumber numberWithInteger:[sender tag]] repeats:YES];
+    
+    // ...and also execute it right now
+    [animation fire];
+}
+
 - (void)selectedVisualization:(NSMenuItem *)sender {
     // Turn off all other LED menu items
     if (menuColors != nil) {
             [[menuVisualizations itemAtIndex:i] setState:NSOffState];
         }
     }
+    if (menuDisplays != nil) {
+        for (int i = 0; i < [menuDisplays numberOfItems]; i++) {
+            [[menuDisplays itemAtIndex:i] setState:NSOffState];
+        }
+    }
     [buttonOff setState:NSOffState];
     [sender setState:NSOnState];
     
-    // Check if a static color was selected
+    // Check if it is a display
     BOOL found = NO;
-    if (staticColors != nil) {
+    if ([sender tag] > -1) {
+        found = YES;
+        [self displayVisualization:sender];
+    }
+    
+    // Check if a static color was selected
+    if ((found == NO) && (staticColors != nil)) {
         for (NSString *key in [staticColors allKeys]) {
             if ([sender.title isEqualToString:key]) {
                 found = YES;
         }
     }
     
-    if (!found) {
+    if (found == NO) {
         // Check if an animated visualization was selected
         if ([self timedVisualization:[sender title]] == NO) {
             NSLog(@"Unknown LED Visualization selected!\n");
 // ------------------- Visualizations -------------------
 // ------------------------------------------------------
 
+- (void)visualizeDisplay:(NSTimer *)timer {
+    NSBitmapImageRep *screen = [Screenshot screenshot:[timer userInfo]];
+    
+    if ((([screen samplesPerPixel] != 3) && ([screen samplesPerPixel] != 4)) || ([screen isPlanar] == YES) || ([screen numberOfPlanes] != 1)) {
+        NSLog(@"Unknown image format (%ld, %c, %ld)!\n", (long)[screen samplesPerPixel], ([screen isPlanar] == YES) ? 'p' : 'n', (long)[screen numberOfPlanes]);
+        return;
+    }
+    
+    int redC = 0, greenC = 1, blueC = 2;
+    if ([screen bitmapFormat] & NSAlphaFirstBitmapFormat) {
+        redC = 1; greenC = 2; blueC = 3;
+    }
+    
+    unsigned char *data = [screen bitmapData];
+    unsigned long long width = [screen pixelsWide];
+    unsigned long long height = [screen pixelsHigh];
+    unsigned long long max = width * height;
+    unsigned long long red = 0, green = 0, blue = 0;
+    for (unsigned long long i = 0; i < max; i++) {
+        red += data[([screen samplesPerPixel] * i) + redC];
+        green += data[([screen samplesPerPixel] * i) + greenC];
+        blue += data[([screen samplesPerPixel] * i) + blueC];
+    }
+    
+    [self setLightsR:(red / max) G:(green / max) B:(blue / max)];
+}
+
 - (void)visualizeGPUUsage:(NSTimer *)timer {
     NSNumber *usage;
     NSNumber *freeVRAM;

CaseLights/Base.lproj/MainMenu.xib

                 <outlet property="buttonOff" destination="gT4-tm-Hvn" id="EEv-lf-Qo7"/>
                 <outlet property="menuAnimations" destination="FJm-ND-abA" id="iGI-Hg-tms"/>
                 <outlet property="menuColors" destination="ZKz-ek-t6c" id="B2S-fy-Ca6"/>
+                <outlet property="menuDisplays" destination="Qgx-6D-9dl" id="MaT-c8-dLX"/>
+                <outlet property="menuItemDisplays" destination="1Cz-Xz-d16" id="rRz-n5-n2P"/>
                 <outlet property="menuPorts" destination="lFU-D0-M5p" id="pHd-AA-S3J"/>
                 <outlet property="menuVisualizations" destination="yZl-ae-7SI" id="b2b-dW-mvy"/>
                 <outlet property="statusMenu" destination="g7M-LS-DgA" id="txO-T1-8yD"/>
                     <modifierMask key="keyEquivalentModifierMask"/>
                     <menu key="submenu" title="Visualizations" id="yZl-ae-7SI"/>
                 </menuItem>
+                <menuItem title="Displays" hidden="YES" id="1Cz-Xz-d16">
+                    <modifierMask key="keyEquivalentModifierMask"/>
+                    <menu key="submenu" title="Displays" id="Qgx-6D-9dl"/>
+                </menuItem>
                 <menuItem title="Brightness" id="Oh0-1U-yDg">
                     <modifierMask key="keyEquivalentModifierMask"/>
                     <menu key="submenu" title="Brightness" id="jRu-sM-3xB">

CaseLights/Info.plist

 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>
-	<string>118</string>
+	<string>132</string>
 	<key>LSApplicationCategoryType</key>
 	<string>public.app-category.utilities</string>
 	<key>LSMinimumSystemVersion</key>

CaseLights/Screenshot.h

+//
+//  Screenshot.h
+//  CaseLights
+//
+//  Created by Thomas Buck on 27.12.15.
+//  Copyright © 2015 xythobuz. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface Screenshot : NSThread
+
+// Register and de-register the callback for configuration changes
++ (void)init:(AppDelegate *)appDelegate;
++ (void)close:(AppDelegate *)appDelegate;
+
+// List available displays. Returns an array of numbers.
++ (NSArray *)listDisplays;
+
++ (NSString *)displayNameFromDisplayID:(NSNumber *)displayID;
++ (NSBitmapImageRep *)screenshot:(NSNumber *)displayID;
+
+@end

CaseLights/Screenshot.m

+//
+//  Screenshot.m
+//  CaseLights
+//
+//  Based on the Apple ScreenSnapshot example:
+//  https://developer.apple.com/library/mac/samplecode/ScreenSnapshot/Listings/ScreenSnapshot_ScreenSnapshotAppDelegate_m.html
+//
+//  Created by Thomas Buck on 27.12.15.
+//  Copyright © 2015 xythobuz. All rights reserved.
+//
+
+// Uncomment to store a screenshot for each display in the build directory
+//#define DEBUG_SCREENSHOT
+
+#import "AppDelegate.h"
+#import "Screenshot.h"
+
+static BOOL displayRegistrationCallBackSuccessful;
+
+static void displayRegisterReconfigurationCallback(CGDirectDisplayID display, CGDisplayChangeSummaryFlags flags, void *userInfo) {
+    AppDelegate *appDelegate = (__bridge AppDelegate*)userInfo;
+    static BOOL DisplayConfigurationChanged = NO;
+    
+    // Before display reconfiguration, this callback fires to inform
+    // applications of a pending configuration change. The callback runs
+    // once for each on-line display.  The flags passed in are set to
+    // kCGDisplayBeginConfigurationFlag.  This callback does not
+    // carry other per-display information, as details of how a
+    // reconfiguration affects a particular device rely on device-specific
+    // behaviors which may not be exposed by a device driver.
+    //
+    // After display reconfiguration, at the time the callback function
+    // is invoked, all display state reported by CoreGraphics, QuickDraw,
+    // and the Carbon Display Manager API will be up to date.  This callback
+    // runs after the Carbon Display Manager notification callbacks.
+    // The callback runs once for each added, removed, and currently
+    // on-line display.  Note that in the case of removed displays, calls into
+    // the CoreGraphics API with the removed display ID will fail.
+    
+    // Because the callback is called for each display I use DisplayConfigurationChanged to
+    // make sure we only disable the menu to change displays once and then refresh it only once.
+    if (flags == kCGDisplayBeginConfigurationFlag) {
+        if (DisplayConfigurationChanged == NO) {
+            [appDelegate clearDisplayUI];
+            DisplayConfigurationChanged = YES;
+        }
+    } else if (DisplayConfigurationChanged == YES) {
+        [appDelegate updateDisplayUI:[Screenshot listDisplays]];
+        DisplayConfigurationChanged = NO;
+    }
+}
+
+@implementation Screenshot
+
++ (void)init:(AppDelegate *)appDelegate {
+    // Applications who want to register for notifications of display changes would use
+    // CGDisplayRegisterReconfigurationCallback
+    //
+    // Display changes are reported via a callback mechanism.
+    //
+    // Callbacks are invoked when the app is listening for events,
+    // on the event processing thread, or from within the display
+    // reconfiguration function when in the program that is driving the
+    // reconfiguration.
+    displayRegistrationCallBackSuccessful = NO; // Hasn't been tried yet.
+    CGError err = CGDisplayRegisterReconfigurationCallback(displayRegisterReconfigurationCallback, (__bridge void * _Nullable)(appDelegate));
+    if (err == kCGErrorSuccess) {
+        displayRegistrationCallBackSuccessful = YES;
+    }
+}
+
++ (void)close:(AppDelegate *)appDelegate {
+    // CGDisplayRemoveReconfigurationCallback Removes the registration of a callback function that’s invoked
+    // whenever a local display is reconfigured.  We only remove the registration if it was successful in the first place.
+    if (displayRegistrationCallBackSuccessful == YES) {
+        CGDisplayRemoveReconfigurationCallback(displayRegisterReconfigurationCallback, (__bridge void * _Nullable)(appDelegate));
+    }
+}
+
++ (NSArray *)listDisplays {
+    CGDisplayCount dspCount = 0;
+    CGError err = CGGetActiveDisplayList(0, NULL, &dspCount);
+    if (err != CGDisplayNoErr) {
+        NSLog(@"Couldn't list any active displays (%d)!\n", err);
+        return nil;
+    }
+    
+    CGDirectDisplayID *displays = calloc((size_t)dspCount, sizeof(CGDirectDisplayID));
+    err = CGGetActiveDisplayList(dspCount, displays, &dspCount);
+    if (err != CGDisplayNoErr) {
+        NSLog(@"Couldn't get active display list (%d)!\n", err);
+        return nil;
+    }
+    
+    if (dspCount > 0) {
+        NSMutableArray *array = [NSMutableArray arrayWithCapacity:dspCount];
+        for (int i = 0; i < dspCount; i++) {
+            [array addObject:[NSNumber numberWithInt:displays[i]]];
+        }
+    
+        return [array copy];
+    } else {
+        NSLog(@"No displays found!\n");
+        return nil;
+    }
+}
+
++ (NSString *)displayNameFromDisplayID:(NSNumber *)displayID {
+    NSDictionary *displayInfo = CFBridgingRelease(IODisplayCreateInfoDictionary(CGDisplayIOServicePort([displayID unsignedIntValue]), kIODisplayOnlyPreferredName));
+    NSDictionary *localizedNames = [displayInfo objectForKey:[NSString stringWithUTF8String:kDisplayProductName]];
+    
+    // Use the first name
+    NSString *displayProductName = nil;
+    if ([localizedNames count] > 0) {
+        displayProductName = [localizedNames objectForKey:[[localizedNames allKeys] objectAtIndex:0]];
+        
+#ifdef DEBUG
+        NSLog(@"Display %u named \"%@\"!\n", [displayID unsignedIntValue], displayProductName);
+#endif
+    }
+    
+    return displayProductName;
+}
+
++ (NSBitmapImageRep *)screenshot:(NSNumber *)displayID {
+    CGImageRef image = CGDisplayCreateImage([displayID unsignedIntValue]);
+    NSBitmapImageRep *imgRep = [[NSBitmapImageRep alloc] initWithCGImage:image];
+    CFRelease(image);
+    
+#ifdef DEBUG_SCREENSHOT
+    NSData *data = [imgRep representationUsingType:NSPNGFileType properties:[NSDictionary dictionary]];
+    NSString *path = [NSString stringWithFormat:@"test-%u-%@.png", [displayID unsignedIntValue], [Screenshot displayNameFromDisplayID:displayID]];
+    NSError *error;
+    if ([data writeToFile:path options:0 error:&error] == YES) {
+        NSLog(@"Wrote debug image to \"%@\"\n", path);
+    } else {
+        NSLog(@"Error writing debug image to \"%@\": %@\n", path, error);
+    }
+#endif
+    
+    return imgRep;
+}
+
+@end

CaseLights/Serial.m

 
 #import "Serial.h"
 
+#define MAX_SEND_ERRORS 10
+
 @interface Serial ()
 
 @property (assign) int fd;
     NSLog(@"Sending string %s", data);
 #endif
     
+    int errorCount = 0;
     ssize_t sent = 0;
     while (sent < length) {
         ssize_t ret = write(fd, data + sent, length - sent);
         if (ret < 0) {
             NSLog(@"Error writing to serial port: %s (%d)!\n", strerror(errno), errno);
+            errorCount++;
+            if (errorCount >= MAX_SEND_ERRORS) {
+#ifdef DEBUG
+                NSLog(@"Too many send errors! Giving up...\n");
+#endif
+                return;
+            }
         } else {
             sent += ret;
         }