Video Transcript
Part B: Block Controller B
9m 19s
0:08
Welcome back. Let’s dig a little deeper into the Block controller, and look at some of
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the remaining types of blocks you have at your disposal.
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Back inside the Block Controller edit screen, let’s look at another type of block. Look
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under “Flow Control.” These blocks will only perform their action based on certain
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parameters. It’s like a flow chart, where a decision point is made and a new path diverges
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based on your answer. Let’s grab this one that says “if / do”. This block has a lot going on.
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You’ll notice that it has a slot here at the top, which means it’s a command. It has
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a slot here for a value or parameter, and it has an open mouth for what
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we want it to do. It also has this cog icon, which we’ll talk about in just a bit. But for
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now let’s integrate it with the rest of our program.
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In the previous video we made a button that changes its label or Legend to “ON”
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when it’s pressed. But in order to change that label to “OFF” when the button is
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pressed again, we’re going to need the program to make an evaluation. If the state
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of the button is ON, then we want the label to say on. If the state of the button is off,
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then we want the label to say OFF. That’s flow control. So let’s undock our “set control”
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block from the “control change” block, and add it to our “If” block instead. Now we can
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drag the “If” block into the “control change block.” Essentially, when the button
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is pressed, it’s only going to change the label if a certain requirement is met.
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You can guess which part we need to complete now – if … what? We’ll need to add a
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block here that equates to “if the control is on.” Next let’s look under the Operators
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branch. Operators are things that, well, perform an operation. In this case, usually
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mathematical operations such as basic arithmetic, or logical operations such as comparing
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the equality of two different things. That’s what this Logic block does, that says
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“blank equals blank.” This will work perfectly for us, so let’s snap this to our “If” block.
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Now we see a new type of block connection. Rather than slots on the edge, this
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block has holes. We’ve seen the type of block that fits in this hole before, with a triangular
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tab on the side, right? These are values, or parameters. If we go back to our
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“AMAZING” control branch, let’s grab this parameter: “AMAZING Boolean.” If you’re
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not familiar with the word Boolean, it basically means a binary state, something that
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only has two options, like our button. For our second hole, let’s look back in the Values
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branch, and we’ll grab that “True/False” block. We can snap this into our Logic block’s second hole.
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So let’s read our program so far – when the control changes, if the control’s state is
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true, then we’ll change the label to “ON.” All that’s left is to define what happens
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when the state is false. But where are we supposed to define this? There are no
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more empty slots in this block! To fix this, we’ll have to use that cog icon we saw earlier.
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Certain blocks like this one can have customizable configurations. This little window
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that pops up is sort of a miniature version of the Block controller interface. On
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the right is our block, and on the left is the library of possible things we can add to
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that block – just like the main interface. Let’s drag a new option into our block – the
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“Else” option. When we add the “Else” in this configuration window, we can see that
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the block itself has changed in the main window. We now have a new area to add a second command.
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Let’s close the configuration window by clicking the cog icon again. We need another
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“set Legend” block for this new section, but we can simply copy and paste our first
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one. Most Windows shortcut keys work in the Block Controller editor. I will Control+C
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to copy and Control+V to paste, and add this as our “Else” command. All that’s
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left is for me to change the Legend string from ON to OFF.
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So let’s read our script one final time. When the control changes, if the control’s
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state is true, we’ll change the label to “ON.” Otherwise, we’ll change the label to
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“OFF.” Looks good! There are a few final things I want to show you before we’re
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done. First, we have to press this yellow “Save changes” bar at the top in order for
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this code to become active. This allows you to work on your program on a live system
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without disrupting anything. Until you press “Save Changes” the old code is still running.
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Once I press this, we can return to the Designer schematic to look at our button, and
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make sure it works. When I turn the button off, the label says OFF. When I turn it on,
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the label says ON. Excellent!
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Okay, you’re right. It took us ten minutes to get a button to change labels, it’s not
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that impressive. YET. We just did this as a tutorial on how the blocks connect to each
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other. In reality, you’re going to do far more complicated things with the Block controller.
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For instance – one important thing you should know is that you can stack commands
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on top of each other. These blocks may look rigid, but they’ll adapt their size to whatever you need.
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Let’s say I wanted to change the color of this button as well. I could add a “Set Color”
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command into this block, and the block will adjust to accommodate it. You can add
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as many commands as you want this way – which means that when the button is
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pressed it can change its label and change its color, and reset another control, and
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start a timer, and activate a third-party lighting device, and change the layer that’s
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visible on the UCI, and launch the pyrotechnics, etc., all at the same time. Now we’ve
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got a button that’s doing a lot more than changing its label. That’s the point. That’s
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where we’re headed. But for now, I’m going to keep mine simple, and add commands
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that simply make the button green when the button is on, and red when the button is off.
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Once again I can save my changes, and then back in the Schematic I’ve
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got a button that changes its color and its label as you interact with it.
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Another very important thing in the Block Controller – if you right click on a block,
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there are a couple of options for you. You could select “Show Comment” which gives
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you a comment section at the top of the block. This lets you type in whatever you
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like, which has absolutely no effect on the functionality of the block. So if you want
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to remind yourself what this block does, you can give it a title. You could also choose
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“Collapse Block” which will truncate the block down to a single visual line, without
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changing the code. This can be very convenient if you have a lot of blocks in your
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program and need to focus on one at a time. The jagged scale line indicates that
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there is more to see, and you can always Expand the block again to reconfigure it.
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Alright, one final thing. I saved the best for last! We mentioned earlier that the Block
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controller is a great bridge between people who don’t write code – like me – and the
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ability to accomplish things that require scripting. Well these visual blocks are literally
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writing the code for you, and you can read that code by navigating to the “Lua” tab.
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This is the Lua script of what we’ve done so far. This stuff at the top is just housekeeping,
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while the block we built is represented down here. You can even kind of read it,
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now that you understand how the language is structured. If you knew how to
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write script before this, you could have written all this out rather than use the Block
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Controller at all. But if you typed anything wrong, if you missed a capital letter, or if
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you weren’t exactly sure how to format it, then the script wouldn’t work. The Block
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Controller takes all that worry away by letting you build your program with easy to
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manage puzzle pieces, and the code is written in the background – free of any syntax errors.
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If you’re interested in learning scripting, reading this Lua tab might help you on your
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way. In fact, if you want to further edit this script yourself now, you could select this
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icon at the top and choose “Convert to Script.” However, a warning will pop up now,
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and with good reason. You can convert blocks to script, which allows you to continue
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editing in Lua, but you cannot convert those edits back into blocks. Once you select
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OK, the interface changes to an editable text scripting screen. You do have the option
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to “Revert to Blocks” but doing so will revert it back to its original blocks, so you
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would lose any changes you made in Lua.
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So, that’s the Block Controller component. We obviously only skimmed the surface
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of what it can do, and what each of the different blocks in each category are. Mostly
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we wanted to show you how the blocks connect to each other, demonstrate how
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some are customizable, and hope you feel comfortable navigating the edit window
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now that you know what options are available to you. In upcoming videos, we’ll go a
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little slower and talk about the concepts of a programming language, and see how
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each idea is implemented both in Lua and in the Block Controller. Thanks for watching.
Lesson Description
Part B: Block Controller B
9m 19s
Learn about sections of the Block Controller, including control change, flow control, if statements, operators, boolean values, and converting blocks to lua script.
Downloads and Links
Part B: Block Controller B
9m 19s