Always On Displays Get Clever In sports
This is an informational piece of content explaining some of the power-saving and usability features made possible by precisely controlling screen elements of energy-hungry screens. Plus covering some new announcements for later in the year.
Always On Displays are, well, always on. Confusingly, this doesn’t mean that your screen will always show the same screen content. Let me explain…
Limitations & Annoyances
It’s annoying when you can’t read what’s on your expensive watch’s face. That could be because the backlight isn’t on or because an AMOLED-type screen has simply turned off to save power.
Perhaps when you want to know the time it’s OK to wait for a split-second for the display to turn on as you raise your wrist but in sport, I find it really (like, really) annoying if there is any kind of delay.
To have a permanently active display will consume more energy and having a permanently active backlight will consume considerably more energy. Thus there are compromises to be made and technical hurdles to overcome to address this problem.
Ranges of solutions include
- User-defined backlight setting for timeouts and percentage brightness levels – Garmin does this
- Optimised algorithms that properly detect wrist actions that really signal your intent to view the screen – Suunto and others do this
- Screen tech that very quickly turns the screen on – Apple tries to do this
- Dimming of the screen – Apple and others do this
- Selective dimming or hiding of individual elements on a screen
So, there are some quite clever things going on here. For the likes of Garmin, such fine-tuning of the screen is only kinda important, so long as the backlight isn’t always on the battery-friendly Garmin tech isn’t going to be challenged too much. Yet, of course, Garmin still wants to get those headline battery life numbers to go as high as possible.
Higher-resolution, more vivid smartwatches, on the other hand, face a pressing need to REALLY control the screen’s power consumption. Their AMOLED-like screen can suck that day and a half long battery life dry very quickly if you’re not careful.
Always-On Displays on Apple Watch – What’s new later this year
Apple Watch SE and Apple Watch 4 and below do not have always-on screens. More positively put, Apple Watches 5 & 6 do have an always-on display. I’ve used every Apple Watch model and the one aspect that annoys me most is the lack of an always-on screen on the lower models but even the always-on screens were not what I originally imagined.
- Active – The screen is well and truly on.
- Always On – The screen shows something but some element of it may be obscured, dimmed, blurred or replaced
- Inactive – It’s black.
Has Apple been cheating?
However, Apple has been kinda-cheating so far with its always-on display. Typically 3rd party applications have only been able to show a blurred always-on screen plus a clear digital clock and even Apple’s own workout app only shows a dimmed version of your progress when the wrist is down. However, because the screen is powered-on in these scenarios, it responds more than acceptably quickly to a wrist-raise action, further helped by the wrist-raise action being generally well detected by Apple.
Later this year Apple is introducing new ways that developers can control app screens in watchOS 8. This will soon start to feature on watches that support watchOS 8 namely Apple Watch 6, AW5 and the new Apple Watch 7 in September.
What screen behaviours we will start to see on watchOS
Soon we will see entire app screens being dimmed or desaturated.
However, there will also be more subtle power saving controls whereby the refresh rate of an always-on screen element will be controlled to allow a maximum of one refresh per second in always-on mode. An example of this would be where the always-on screen is dimmed and the frequently-changing tenth/hundredths of a second information entirely removed. The timer still clicks over once per second but power is saved by fewer screen refreshes per second.
There are also ways to control less frequently updated information where the screen is updated at regular intervals like the interval times on 1-minute intervals or refreshed at periodic intervals like whenever the next phase of a complex structured workout is triggered.
Main screen complications can be immediately refreshed based on critical events in HealthKit (eg fall events) and other information that is deemed by the developer to be sensitive in some way can also be hidden from prying eyes in always-on mode eg your heart rate.
There are also new possibilities to display Bluetooth sensor data as complications via background app refreshes.
You may not have known that the beautiful, AMOLED-like screen can be made more power-friendly by controlling the power consumption of individual parts of the display.
Whilst changing the appearance of the whole or part screen is nothing new, we will increasingly see the more precise control of parts of screen as a means of saving power that sets more advanced health & fitness watches apart from the competition.
These kinds of precise ways of controlling screens are important to the battery lives on the sports apps you might use on your smartwatches (Apple, Vivoactive, Venu) but less important to out-and-out sports watches (Forerunner, Fenix)
Importantly for Apple I suspect this will only tickle at the edges of the battery lives currently achieved but the user experience in sports apps will be further improved and User Experience is super important!