Month: April 2018

Good Morning from my Robotics Lab! This is Shadow_8472, and today, I am returning to the modded MineCraft world where I am working on exactly what I said I wanted to move on from last week. Let’s get started.

The smeltery program I wrote for last week was nice and all, but it had a bunch of potential improvements. For one, it was blind to its environment. It could only send out pulses when it was time for the next one. Plus, with the “analogue” capabilities of the regular computers, and my previous experience with dealing with analogue redstone, I was tempted beyond my ability to resist to tear out some space around the smeltery and upgrade the hardware.

Observer blocks were capable of giving off a pulse when a basin or table was filled and quickly emptied by a hopper. There are six sides in total for the computer to work with, but the front is on display and the top of this one is occupied with another block while the tight quarters makes threat of cross wiring redstone lines very real. Given these limitations, I set about working on a new setup capable of taking advantage of  the rs.setAnalogueOutput(string side) and rs.getAnalogueInput(string side) functions.

While I was working on the new hardware, I decided to combine the programs, and add functionality so I could pour from both places at once. I set to work with three modes in mind, meant to run almost the same code at once: “Basins”, “Tables”, and “Both”. (For the aspiring coders and grammar critics, the punctuation outside the quotes is intentional; the quotes mark the beginning and end of strings, or lengths of characters (a single symbol like a letter or digit).) The code quickly became messy, and I started going into writing functions to modularize the more deeply nested segments of code. I used a little trick I learned while writing assignments in C++ where I made a comment consisting of the comment character such that it covered a line of the editor.

//////////////////////////////////////////////////////////////////////////////////////////////////////////

The section break I just put in works in C++. Unfortunately, when I tried the Lua equivalent, WordPress changed the repeated — into a single line. Anyway, the trick is that after the comment signal, the rest of it can be either an odd or even number of character repetitions, even if the first  is double. The trick helped a little, and I pushed on, working from the extremities of the code to the main loop until I realized a bit of a mistake.

My original program was designed to loop over a number of pours to a single output. I wanted the new program to handle both at once and possibly more. I was nearing completion when I when I came to halt. The main loop was incompatible with handling both outputs at once. Ouch!

I went about redesigning it in my head, but the project just kept inflating and inflating. Soon enough, it was too big without additional notes, so I just modified my old program to work with my new hardware. Funny, how an estimated one day project ended up taking half the week and it wouldn’t have worked anyway. At this point, I am content to just leave that as it is. The hardware is set up such that the computer can tell which set of outputs to trigger and which outputs are responding, but the program doesn’t use the full functionality.

/*********************************************************************************************/

Another example of my section break for C++. This one uses the long comment format. I’ve thrown together a few more programs, but nothing amazing, and nothing refined. I have noticed a consistent pattern: once I get the code working, I want to make another, better version. ‘Maybe if I just make it do this a little bit differently…’

For my automated skeleton grinder, I already have coded up the turtles to kill the skeletons. They aren’t perfect, but they sort out the unstackables by themselves. I also learned a little more about their inventory management, so I have another idea on how to make them handle better. Besides, I also want to use more turtles to move the items about better and free up the attack turtles to actually do their main job.

My goal for this week is to fully automate the farm, at least in code even if I don’t get a presentable design in order.

Final Question: Problems can usually be solved from any different number of angles. What was the last time you scrapped progress in favor of an easier approach?

Good Morning from my Robotics Lab! This is Shadow_8472 and today, I am taking a field trip. My sister set up a modded MineCraft World, and I am into the ComputerCraft mod. Let’s get started.

ComputerCraft is a MineCraft mod that adds computers that run actual code using Lua, a scripting language. While a lot of programs are written, compiled (turned into something the target machine can run), and executed; scripting languages are more often just run off the text file as written. They will be slower, but easier to write.

ComputerCraft itself adds basic and advanced versions of both regular computers and their robot counterparts or “turtles” as well as a few other peripherals. All computers come with a Command Line Interface. Advanced computers will even let you use your mouse and show you colors while editing a program. Nevertheless, it’s the perfect mod for dealing with computers from a programmer’s point of view. In a multi-player environment, one might even get into hacking other’s networks while defending one’s own with encryption.

One mechanic within MineCraft proper I will be relying on is redstone. Think of it as a simple wire. Signal in one end,

I have dealt with ComputerCraft before. It was a few years ago, but it’s not totally new to me. Back then, I was a complete stranger to Lua and was only interested in the early game mining abilities. Other stuff was a little low level for my patience. I eventually set to modify the code for a mining turtle’s default pit digging program. In my research before reprogramming the turtle, I did not find the copy command, so I retyped the whole thing in myself before attempting the modification. Not a smart move without a second screen. But I did get the gist of the syntax of Lua and an insight into how the program was structured. It was a good way to learn the language.

In the present, I am looking to use in-game computers to manipulate the world in more ways than just mining it. I have already used a script to automate a tedious task from another mod, in this case Tinkers’ Construct, where I would otherwise have my time taken up by micromanaging the pouring of blocks and ingot casts. It provided a refresher course on programming and in Lua in particular.

I started with a description of the problem: Automatically pour from the smeltery. I formed a mental picture of how I wanted the program to do it: Send redstone pulses to the appropriate spouts. At this point, I start mapping out the logic of the system. Normally, such a stage would be done on a whiteboard or a piece of paper, but this was a small enough job, I broke good programming practice and skipped this step.

Coding the smeltry program was fairly easy. I pulled up the source code for the default mining program on my second screen and referenced it for syntax. I usually find examples a lot easier to follow than a paragraph explanation in some documentation.

What I do find helpful is bringing up the API’s (Application Programming Interface) for ComputerCraft elements I’m working with, so I can see what variables of what types the lower level functions want and in what order they want them. Think about it as tying an extra fancy knot and someone gives you a box of strings so you don’t have to make your own rope.

Debugging for the smeltery program wasn’t the smoothest. A programming practice I failed to follow was postponing the debugging until the program was fully written. I don’t like syntax errors. I don’t remember all the errors I had, but one of them stuck out as being stubborn. I eventually got it figured out and I could start debugging the logic.

The completed program has two inputs, both integers. The first is how many pulses to send, and the second is how long to wait between each pulse, as the a premature pulse can stop the flow. The final smeltery has two copies of this program, each a slightly modified to send the pulse to the correct place. Now that I think about it, I could have combined them with an in-program menu. Of course, I could always make it fancier and fancier, but it works for now, and I want to work on other things.

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What? I underestimated the basic computer’s abilities. It CAN use analogue redstone signals. I will have to take advantage of that later on…

Final Question: Have you ever overestimated something and later took advantage of the previously overlooked abilities?