After a bit of experimentation I found the easiest solution was to add a gradient layer to a custom UIControl and swap it with a different layer when the control became highlighted.

The first step was to was to create a custom UIControl class and add a gradient background layer:

#import <QuartzCore/QuartzCore.h>
 
@interface GradientControl : UIControl
{
    CAGradientLayer *normalBackground;
}
@end
 
@implementation GradientControl
- (id) initWithCoder:(NSCoder *)aDecoder
{
    if (self = [super initWithCoder:aDecoder])
    {
        self.backgroundColor = [UIColor clearColor];
 
        normalBackground = [CAGradientLayer layer];
        normalBackground.frame = self.bounds;
        normalBackground.cornerRadius = 10;
        normalBackground.borderWidth = 1;
        normalBackground.borderColor = [[UIColor whiteColor] CGColor];
 
        normalBackground.colors = [NSArray arrayWithObjects:
                                   (id)[[UIColor colorWithHexString:@"a9aeba"] CGColor],
                                   (id)[[UIColor colorWithHexString:@"7e8790"] CGColor],
                                   (id)[[UIColor colorWithHexString:@"6f778b"] CGColor],
                                   (id)[[UIColor colorWithHexString:@"5b657d"] CGColor],
                                   nil];
        normalBackground.locations = [NSArray arrayWithObjects:
                                      [NSNumber numberWithFloat:0],
                                      [NSNumber numberWithFloat:0.5],
                                      [NSNumber numberWithFloat:0.51],
                                      [NSNumber numberWithFloat:1],
                                      nil];
    }
 
    return self;
}
@end

Next we need to add a UIView to our main view in Interface Builder and set the class property to our new custom GradientControl:

Now if we run it in the simulator we can see our new shiny rounded gradient control:

Although this new component responds to events and triggers any actions that you assign it doesn’t give any visual feedback to taps. This can be solved by creating a second gradient layer and swapping the layers when the highlight value changes:

#import <QuartzCore/QuartzCore.h>
 
@interface GradientControl : UIControl
{
    CAGradientLayer *normalBackground;
    CAGradientLayer *highlightBackground;
}
@end
 
@implementation GradientControl
- (id) initWithCoder:(NSCoder *)aDecoder
{
    if (self = [super initWithCoder:aDecoder])
    {
        self.backgroundColor = [UIColor clearColor];
 
        normalBackground = [CAGradientLayer layer];
        // setup normal background...
 
        highlightBackground = [CAGradientLayer layer];
        // setup highlight background...
    }
 
    return self;
}
 
- (void) setHighlighted:(BOOL)aHighlighted
{
    BOOL oldHighlighted = self.highlighted;
    [super setHighlighted:aHighlighted];
 
    if (oldHighlighted == aHighlighted)
    {
        return;
    }
 
    if (aHighlighted)
    {
        [self.layer replaceSublayer:normalBackground with:highlightBackground];
    }
    else
    {
        [self.layer replaceSublayer:highlightBackground with:normalBackground];
    }
}
@end

Now when we tap the control the background seamlessly switches to the highlighted background:

The last thing to do is to add some setters to change the background colours and the border. With these we can easily create a range of gradient controls:

The full code with examples can be found on GitHub.

After using the Nova+ plus for a while I came to realise that the aluminum windshield that is supplied with the stove was tricky to use, not very sturdy and not that effective. I liked the stove and was impressed by its performance but something had to be done about the windshield.

While looking for a spares kit to service my stove I noticed that Optimus manufacture an adapter to mount the burner of a Nova/Nova+ stove inside the windshield of a Trangia. I had used Trangia stoves in the past and knew that they were sturdy, lightweight and compact. When a local camping store had a Trangia 25-2UL (ultra-light, large with kettle) on sale I decided to buy one and try the adapter.

Fitting the adapter

1. Remove the fuel line from the stove.
2. Turn the stove upside down and unscrew the nut that holds the burner to the body.
3. Remove the body (leave the priming wick attached).
4. Fit the adapter clip and priming cup then secure using the nut removed earlier. I had to enlarge the hole on the adapter as it was too small to fit on my burner.
5. Reattach the fuel line.

The adapted burner can now be dropped into the the hole where the Trangia burner goes and the fuel line threaded through the hole that the Trangia gas adapter uses.

Testing the adapter and final thoughts

Now that the adapter was fitted it was time to see how it performs by boiling a kettle. The Trangia base was much more stable than the Nova+ base and the built in windshield was significantly more effective than the flimsy foil one. The only downside to the Trangia/Nova+ hybrid is that the burner is recessed in the base of the Trangia windshield which makes it a bit tricky to light the stove. This is only a minor downside and is outweighed by the benefits of the Trangia base.

The Trangia/Nova+ hybrid combines some of the best features of both stoves and should serve me well for the foreseeable future. Carrying the Trangia burner as well as the Nova+ burner will also add the ability to burn alcohol based fuels (methylated spirits) as well petrolium based fuels (petrol, diesel etc) making it even easier to find fuel while travelling.

My recommendation: If you have an Optimus Nova or Nova+ and an old Trangia knocking around then this is a cheap upgrade that will improve your stove. If you don’t already have a Trangia then it is an expensive upgrade but still worthwhile.

So what can we expect from this blog? Well to be quite honest I’m not too sure. I’ve got a few programming and electronics projects in the pipeline that I’m hoping to get time to work on in the near future. Then there are my paddling escapades which at the moment centre around me trying to stay upright in a C1 slalom boat at HPP! And finally there might be some random musings about life, the universe and everything…

Expect things to change as I sort out a final theme and find my way around WordPress. Hopefully things will settle down quickly and this blog will develop into something that everyone can enjoy.