How to enable an "always-on" mode for Venu/AMOLED

I am trying to do a basic Venu watch face where I'm just printing a large font digital time while in "high power" mode and then printing a very small font time when the device enters sleep. The goal is to get an "always-on" functionality working.

The CIQ3.1 release notes say this:

"Always On watch faces behave differently from MIP to AMOLED. With MIP screens, you can use View.onPartialUpdate to update a portion of the screen every second. With AMOLED screen, this is no longer allowed. Instead, when WatchUi.onEnterSleep is called, you are allowed to render a watch face that must obey the rules of the AMOLED burn-in
protector:

No more than 10% screen pixels can be on
No pixel can be on longer than 3 mins

Ways you can prevent burn in are by drawing the time with a thin font, shifting the time every minute as not to repeatedly leave the same pixels on, and not having static tick marks that leave the same pixels on.

Note that watch faces can detect whether a product has screen protection enforced by checking the value of DeviceSettings.requiresBurnInProtection."

I have used the OnEnterSleep method to set a var called lowPower (and the OnExitSleep to clear it) and then I do a forced update via WatchUi.requestUpdate(). The update method then paints the screen black and draws the text. The text is very small and clearly less than 10% of the pixels. I also implemented a basic rotational algorithm where the text is shifted around the screen automatically on every update, as per the requirements above. The text never overlaps with itself so I'm pretty sure I'm meeting all of the burn-in requirements.

In the simulator I see everything working correctly, and I can toggle Low Power Mode and everything appears as I want it to. I also don't get the heatmap warning indicator, so again I'm pretty sure I'm meeting all of the requirements. But when I put the .prg on my watch and try to run it, the watch always turns the display off. I see the high power mode, and then I see the small text when it goes to sleep, but then the display immediately turns off. I'm not sure what I am doing wrong.

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0 georgec over 2 years ago in reply to jim_m_58

It looks like the v4.1.0.beta1 release may have relaxed the 3 minute burn-in protection rule. The release notes mention:

Relax screen burn-in protection rules for Venu 2 and future AMOLED products to only require using less than 10% of screen pixels.

Does that mean that we may not need to worry about shifting pixels or using the checkerboard approach once the new SDK is released?

0 jim_m_58 over 2 years ago in reply to georgec

It sounds to me you still need to worry about the 3 minutes on the Venu and Venu sq.

0 el34rob over 2 years ago

Thanks for this topic. I'm very interested in the checkerboard approach. How does one go about converting a checkerboard vector image to a font that can then be imported into BMFont (I know what to do once it's in BMFont)? Are there some steps you could share please? I tried using one of the online converters (SVG > TTF), but no luck (BMFont doesn't like it). Any help is appreciated. Thanks.

0 el34rob over 2 years ago in reply to el34rob

Sigh... I think I worked it out. Save the SVG as a PNG file and use the Image manager within BMFont to assign it to a particular ASCII position within a font. export the Bitmap Fonts. voila!

0 BobMiles over 2 years ago in reply to jim_m_58

Looking at the stock faces on the epix, they use a few more tricks.

For example the hands have a black frame around which helps because touching hands often trigger the 3 min rule. It seems that they use the checkerboard for the data fields, too but in some places change the color to a little brighter where they overlay the checkerboard so it is not as noticeable.

But then there are some things that just don't seem to obey the rules at all. So maybe the 3 min rule will fall eventually.

0 8049786 over 2 years ago in reply to jim_m_58

Is there any sample code on how to use the checkerboard mask?

0 Felipe over 2 years ago in reply to 8049786

I have already posted it in this same thread a few posts back (check page 3).

0 8049786 over 2 years ago in reply to Felipe

Thanks Felipe!

0 Cristi B over 2 years ago in reply to JArthur650

@JArthur650 did you try to use only vertical black lines? It might look brighter. I'm thinking to try this instead using a font

0 JArthur650 over 2 years ago in reply to Cristi B

I dont think I did. I tried outlines of arms that just followed vector lines in the programming. These were slightly offset each time they were drawn. This worked, but was not visually pleasing. The checkerboard worked much better.