# Set charge level app vs. the car’s screen



## PaulK (Oct 2, 2017)

If I set a charge level precisely (to 60, 70, or 80%) onto the grey line in the app, the screen in the car shows the set point to be just under the tick mark for the same percentage. 

And vice versa... If I set the level prescisely on the tick mark in the car, the app shows it set one line width higher in the app. Seems to equate to only 1% but strange that they don’t match up. 

Does anyone else observe this? Fw 50.6, iOS 12 app 3.8.0


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## jdcollins5 (Oct 31, 2018)

Yes I see the difference between the app and the charging screen to be off slightly.


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## Frully (Aug 30, 2018)

Probably just a matter of the car screen having a lot more pixels to interpret the percentage. The interpolation between % marks doesn't math the same on the smaller screen.


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## mswlogo (Oct 8, 2018)

Two different developers need to have a chat.


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## PaulK (Oct 2, 2017)

Frully said:


> Probably just a matter of the car screen having a lot more pixels to interpret the percentage. The interpolation between % marks doesn't math the same on the smaller screen.


No it's actually different. Match up the lines on the app and it charges to 60%. Match up the lines (tick marks) in the car and it charges to 61%.

It really doesn't matter one iota. But odd that it doesn't match. I think they matched up for the first couple of months I owned the car (July-Aug) so maybe it was introduced in a fw update along the way.


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## Frully (Aug 30, 2018)

I'm probably phrasing it wrong. On the app the interpolation of where the line is drawn is probably a different percentage being requested than where the line is rendered on the car.

Divide <width> pixels on a phone evenly into 100% and you get some fraction of a percent per pixel. Divide the same on the car and you probably have 10+ pixels per percent. I'm saying the math of where that line is rendered just falls over a threshold of 'between 60 and 61%' depending on which system you use to render the tick marks.
Edit: Also, the granularity of the touchscreen digitizers may not resolve down to the pixel level - it may be some other arbitrary scale (like 1024 horizontal segments when there are 1920 actual pixels of width)


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## Bokonon (Apr 13, 2017)

Whatever the cause, it would be nice if they just snapped any selection within 1% of a multiple of 10 to that number. When was the last time someone wanted to charge to 79% or 81%?


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## PaulK (Oct 2, 2017)

Frully said:


> I'm probably phrasing it wrong. On the app the interpolation of where the line is drawn is probably a different percentage being requested than where the line is rendered on the car.
> 
> Divide <width> pixels on a phone evenly into 100% and you get some fraction of a percent per pixel. Divide the same on the car and you probably have 10+ pixels per percent. I'm saying the math of where that line is rendered just falls over a threshold of 'between 60 and 61%' depending on which system you use to render the tick marks.
> Edit: Also, the granularity of the touchscreen digitizers may not resolve down to the pixel level - it may be some other arbitrary scale (like 1024 horizontal segments when there are 1920 actual pixels of width)


Ah yes I see what you're saying now. Yes that may be a logical explanation of why. But, the resolution of the display seems to me to be high enough that they could make the math work (and in fact I believe, but can't prove, that they both did like up together in an earlier fw version).

But I accept it and as I've said, 1% doesn't matter in a practical sense. I'll explain to my OCD side.


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## PaulK (Oct 2, 2017)

Bokonon said:


> Whatever the cause, it would be nice if they just snapped any selection within 1% of a multiple of 10 to that number. When was the last time someone wanted to charge to 79% or 81%?


I totally agree. Or provide an optional text entry to specify charge level.

There's a thread for that: https://teslaownersonline.com/threads/setting-charge-limit-exactly.7272/unread


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## mswlogo (Oct 8, 2018)

There is plenty enough pixel resolution to place the limit marker and grid in the correct place on the phone or the car.
This is just a small "coordination" bug that things are not being calculated/drawn/sensed/snapped/rounded/truncated the same way on the two platforms.

BTW if it was due to pixel resolution difference it would work in one direction better than the other. But that's not the case.


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## Frully (Aug 30, 2018)

I'm reminded of both of these sets:



http://imgur.com/a/r102w

 the worst ways to enter numbers in UI
https://www.designernews.co/stories/84443-redditors-design-worst-volume-sliders-possible and the worst volume sliders


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## mswlogo (Oct 8, 2018)

Frully said:


> I'm reminded of both of these sets:
> the worst ways to enter numbers in UI
> https://www.designernews.co/stories/84443-redditors-design-worst-volume-sliders-possible and the worst volume sliders


That link is hilarious.


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## MelindaV (Apr 2, 2016)

Bokonon said:


> Whatever the cause, it would be nice if they just snapped any selection within 1% of a multiple of 10 to that number. When was the last time someone wanted to charge to 79% or 81%?


or have the option to pick a numeric value


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