Ball Game using Accelerometer & Arduino

 

 Project Proposal PDF : Armball Mania Project Proposal

I was recently experimenting with serial communication between Arduino and ue4 and suddenly had this urge to make a fun sensor controlled game. Something different and intuitive !

Now, I remember that I had the ADXL from my previous project which had become one of my favorite sensor ! - and I knew exactly what to do. I know, I know. Why am I using an accelerometer ! Using a gyro would've been a better idea. And you're right, That's the intuitive part ! 

 

The Arduino Part

Before everything, I needed to test if it even works. So, I created a demo project, where I would control the pitch yaw and roll of a flat rectangular object with live inputs from the sensor which Will be in the users hands. Serial communication was a bit tricky. And I needed to open and close the ports dynamically so that I can change it on the go. After a bit of tweaking, I got it to work !

To summarize the protocol in English, Ue4 would scream to the Arduino through the open tunnel and then Arduino would bundle and send back all the data together as a response. And of course, I had to unpack the data later. This happens over a 1000 time under a second, giving us a latency free experience. 

 

 

Now, before everything. I needed a system in the middle that would filter and smooth out the sensor data to give us a butter like experience, thus I played around with some algorithms and got that done with. But, even with the smoothing - this felt a bit janky and was popping all around, here and there. That's because the accelerometer interprets even the slightest torque from my hand, thus the noise like output ! So, I had to program in a noise reduction system. - that would only allow a certain expected range of change around the present base value. And that actually solved quite a lot of the problem.

 

 

Now, I was going for a game that could be controlled with hand movements. Thus I needed something to attach the hardware with the user's hand, for ease of use. Instead of them just holding it.
So, I got a brand new latex glove and sowed the hardware on it - in a more sci-if way. And lastly, I made sure to make it look cool ! With this sorted out, I programmed in a round object, that would simulate realistic physics and bounce around like a real life ball. And although, things were just starting off at this point - it was possible to balance the ball and keep it in a steady position.

This, although simple - was a fun game on it's own. We could spawn the ball on command and watch it interact with the cube. Simulating, realistic physics ! And. Man, the glove was cool AF. Cutting the fingers was a good idea after-all. It made it so much better ! At this point, the base system was almost ready. Just needed to develop the full fledged game and decorate it !

 

The game development part

So, From here. It's all software stuff !
Which is a good thing because you'll get some insight on my workflow in game design. Now. Two things I needed to get started was, A ball and a football field. I modeled the field with all it's individual parts and imported it at first in ue4. What I had in mind was a 90s retro game but with a dash of modern aesthetic as the basic accent of the visual and design.

So, I wanted the field markings to glow brightly. Which was a good decision because it made the user more aware of the structure of the field and the goal posts. I added to the field structure and design inside of ue4 and it looked really great ! Now, things were looking kinda dark and not properly visible. So, I worked a lot on the lighting and the backdrop. To give it a soft moody aesthetics ! A little bit of fog, some soft lighting and some glow.

With this done, I experimented with the ball a lot.
I made it out to glow red, tried to put a arrow on it's head and a lot more. But at last settled with a red cricket ball ! I brought it in and with it's texture done, I replaced it with our initial spherical object.
( Now, the goofs were about to come ! How about this, I'm going to give the player an option to pick between a ball - seems reasonable, a toy pony and a torus ) That would certainly help spice things up !

And, oh. The ball would emit a red light to make the Player better understanding it's location. The light dynamically interacting with the floor and bleeding off to volumetric looked so trippy. I almost forgot how painfully setting up the camera or was. I tried to make it react to the ball movement but it had some serious drawbacks, which I better not get into at this moment. But, Making it static was so much better, specially when the control for changing it, was with the players !
There was a total of 3 camera angles at this point which was custom made by me. And they could choose any one of it !

There was a short moment where I experimented with some wall variations around the field. So that the ball doesn't fall off. But, later discarded the idea since it would've made it a lot easier ! Okay, now let's get back to lighting and the aesthetic part ! I made two studio light and brought in into the map ! It would hang above the goal post and shed some buttery smooth green light on it. Man, the volumetric made it look so cool ! And it was dynamic. Score a goal and it would change its color to red !
Also, I needed to destroy the old ball object, spawn a new one and increment the current score. Which brings us to the particle effect !

Now, ue4 provides fantastic tools for visual effects. Which helped me a lot to create the particle systems. This world spawn when the ball spawns in the middle of the field and when the player scores a goal ! A little bit of explosion, some magic. That added a lot of impact !

 

 

 

 

 

Wait, it's not done yet !
It took me days to get the UI up and running.
Since I was making everything up from scratch, it took a lot of time and effort. I needed to be able to control the sensitivity, noise reduction and the ports all from the UI ! So, the main menu and the pause menu was to be made. If the port is abandoned, I needed to close it and stop the game. The appropriate message should be displayed and the user should have the ability to open the port back again manually and that would automatically resume the game - all while Making it look good !

After the pause menu was made and working, I wanted to make the main menu dynamic. I thought of having a modeled human hand floating and reacting live to the sensor, so that the user can see their changes to the parameters - live on screen.
And of course I had to work on the lights to make it look beautiful.

 

Guess what's next ?
The sound design. We needed spawn and score sound effects and different background music - all to be custom made !
After giving it some final finishing touches. It was in a presentable position ! Lastly, I would color grade to tweak the look and feel of the game ! And also fixed some bugs.
With everything done, I finally exported and built the game ! Here's the showcase of the whole thing !

Now, the whole project which includes the game, the Arduino code and the instructions is uploaded in game-jolt. For anyone to try it out. Here's the link : Click here

 

Here is the full video log of the development journey !

 

How to use ?

Before you get started, there's some basic things you must do to set this up: You would need an accelerometer of course which is an ADXL345 module and you need to connect it with an Arduino.  Now for this project you just need to hook up the SCL and the SDA pins from the module with that of the Arduino along with the VCC and ground. That's it after you are pretty much done with the hardware part. The code will handle the rest. So, you need to upload the code which is provided with this project into your Arduino.

 

Now, on your PC or laptop, open the game and you'll be greater with the main menu where you can change some parameters. For starters leave the first two as is ( the functions are pretty much self explanatory ) but ! You need to look up through which port your Arduino is connected to your PC and sent the correct port here on the main menu.
Now, Press the big white burn button - that should start everything up and if you have connected everything up properly, it should work wonderfully !
So, press the start game button and you're in.

Here are some shortcuts that might be useful for you : Press B to change the ball type, you can press the space-bar or the I button on your keyboard to spawn in a new ball. And, you can use C to change the camera angle ! Lastly use the ESC key or P on your keyboard to pause the game and access the pause menu ! Where you can find all of these options again !

Now, talking about the game, it's pretty self explanatory. Just pass the ball through one of the two goal posts, and you've scored !

 

 Here is the video tutorial and instructional video !

 

 Presenting ArmBall Mania at the National Exhibition September, 2022

Me and Ranit Bhowmick Presenting the ArmBall Mania at the 75th National Exhibition at the Science Fair Salt-lake. On September 2022.

 

 

Insane response from the Youth at the Exhibition. Here are some video clips.