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I'm trying to make a program on the EV3 that will imitate the shutdown process.

At first, I wanted to make my life easier by naming the program "Shutting Down" and not interfere with the display in any way, because the program execution screen looks almost exactly like the real shutdown screen, however there is one small difference. On the default program execution screen, the line underneath the Mindstorms logo sometimes has parts of it intentionally white-ed out so that it looks like two lines, but the shutdown screen always has one straight black line that never changes. So I decided to go with Plan B.

Plan B was to interfere with the display and make it look 100% like the real shutdown screen. I am a bit new to this, though, and there's one thing about displays that I still don't get. And that is how I'm supposed to have more than one item appear on the screen at a time.

Here are the things I tried:

• I put all the displays in an infinite loop block without any wait blocks, hoping that without wait blocks it will display the images at such a rate that it gives the illusion that they are being shown all at once, but instead, it acted as if I did put tiny wait blocks here and there and the screen flickered, which is not what I want. What's stranger is that they came up in a lighter black than usual, kinda like the EV3 screen was physically dying.

• I put each display block with one play block behind it and nothing else, but the result was that only one of the displays would show up.

Here's the current program, without any display tweaks (other than the completely blank screen). I doubt it will help, but I don't mind if you steal my code and claim it for yourself. It's also possible that the code is messing with the display, but again, I doubt it. Just take a look:

FakeShutdown

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  • I know the/an answer for the nxt, so I figured I'd check to see if it works for ev3: Is there any sort of option (a checkbox, on NXT) associated with the display blocks that says "Clear Screen"?
    – Brandon_J
    Commented May 17, 2020 at 1:34
  • @Brandon_J As you can see in the given program the display block has an image of an eraser and a grey checkmark underneath. This tells that the screen will be cleared, but for some reason it doesn't seem to work for me. Correct me if I'm wrong, but the eraser looks like that on the NXT software, right? Commented May 17, 2020 at 10:31

2 Answers 2

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At the start of the program, add a block that displays a custom image that is exactly the same as the shutdown screen (To make one, go to the tools tab at the top left, and in the drop-down, press "Image Editor") also, you can make a completely blank image for the second display block.

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  • Will try it soon. Thanks! Commented May 23, 2020 at 23:32
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I have figured it out.

At first, I mistook the eraser icon on the display code block for a function that makes the screen completely empty. As it turns out, I am wrong.

As Brandon_J pointed out, the clear-screen function is crucial to the solution. When enabled, it removes any other images that have been on the EV3 screen before it. If I want to show two or more images on the screen, the code should look like this:

code

The first code block has the clear-screen function enabled (the eraser), but the second one doesn't so that the sideways hourglass that comes before it will still stay on the screen. The first display block has clear-screen enabled to prevent odd outputs like the following:

display

If there are multiple display blocks in a loop, the screen will also appear like the above no matter what. There aren't any wormholes for it, and even if you put random code blocks before the displays in a loop in order to reach the program execution screen, you'd still get a similar result. Thus they should be outside of loops.

Alternatively, we can use the image uploader, as user15324 pointed out. This can be accessed by clicking "Tools" and clicking "Image Editor". This allows you to make custom images for the EV3.

howtoaccess

whatitlookslike

You can then press the Save button in the upper-left corner and name your image.

save

The image will automatically appear under the "Project Images" folder in display blocks. It can be used the same way as any other image.

hereitis

In my case, I could've just added this small batch of code to the start of the program. It has a random code block in front of the play button to access the program execution screen, and then a line is added to cover up the existing line that sometimes partially disappears.

lineaddition

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