Timmyton – Interactive Robotic Shark

Next, we will be building the Timmyton, an interactive robotic shark that features a myriad of cool functions and has a unique personality. This robot has become a popular MINDSTORMS icon because it can be built using only the parts from one EV3 retail set (31313), making it accessible to young robotics enthusiasts. It was among the first robots to feature a custom GUI, which streamlines five different operating modes within one program.

In this chapter, we will take a look at how the Timmyton manages to have so many mechanical features and such a compact footprint. We will examine each of the simple machines that work together to animate the Timmyton.

The Timmyton's sophisticated programming makes it a great example of a smart robot. We will program the Timmyton's custom GUI, which will give you the knowledge you need to make...

Technical requirements

You must have EV3 Home Edition Software V1.2.2 or newer installed on your computer. You may also install LEGO Digital Designer (LDD) V4.3 and download the LDD file for this project to guide you in the building process.

The LDD file is available on the Downloads page of the the Builderdude35 website:

http://builderdude35.com/download/timmyton-ldd/

The LDD and EV3 files for this chapter are available on GitHub:

https://github.com/PacktPublishing/Building-Smart-LEGO-MINDSTORMS-EV3-Robots/tree/master/Chapter04

Check out this video to see the robot in action:

https://goo.gl/zfLcf8

Mechanical design

We will start by dissecting the physical components that make this one-kit wonder tick.

Drivetrain

Like the Omnilander and the Security Tank, the Timmyton uses tank-style steering to drive around. However, one glaringly obvious difference should jump out at you—the Timmyton does not have tank tracks! How can it have tank-style steering without having tank tracks?

Even though there are no tank tracks, the drivetrain is still classified as tank-style because the Timmyton steers by varying the power sent to each side. In place of tank tracks, the Timmyton has wheels. One wheel is directly connected to each EV3 large drive motor. The ports for the drive motors follow the typical EV3 convention: the left...

Programming

The Timmyton's program is very complex, more so than anything we have made so far. That is because it is essentially five programs rolled into one, plus the programming for the GUI. Don't fret, though! There will be plenty of new concepts, but at the same time, a good chunk of the programming will be reviewed from the previous few chapters. We will walk through this step by step in a neat, orderly fashion.

Now, it is time to program some interactive features and bring the Timmyton to life.

GUI

When the user starts the Timmyton's program, he or she will be greeted by this screen on the EV3 display:

This is the Timmyton's graphical user interface, or GUI, which allows the user to select one of...

Summary

Wow, we learned a lot in this chapter! Let's review what we covered.

We started by introducing some cool new building techniques, such as creating a unique exterior design, using caster wheels for maximum mobility, and taking advantage of the bevel gear's ability to make both parallel and 90-degree gear meshes. Then, we revisited some of the engineering principles that we learned in earlier chapters, such as tank-style steering (this time with wheels) and cam-and-rod mechanisms.

We also expanded our knowledge of EV3 programming. We learned how to make a custom GUI, then incorporated the color sensor and the random number generator block for the first time. We reapplied beacon following, tank-style remote control, and obstacle detection/avoidance. Throughout the programming process, we saw some examples of how creative programming can give a robot its own unique...