Making accelerometer-based mobile games/toys - the Fun Steps experience

[Can innovation help to new kind of games to be successful? The rarely used features of mobile devices can cause a gaming revolution, or they are just "there" waiting to be discovered? The creators of Fun Steps: Robots and Fun Steps: Cartoons discuss the tech issues and opportunities around their accelerometer-based game/toy.]

Introduction

You know the old story about the shoe-vendors, going to Africa? No? Here we go: "Two salespeople were sent to Africa to open up new shoe markets. Two days after arriving in Africa, one salesman called the office and said, "I'm coming back to the U.S. on the next flight because I can't sell shoes here. Everybody goes around barefoot." On the same day, the other salesman sent an E-mail to the factory saying: "The prospects in Africa are unlimited. Nobody wears shoes here!" 



Translating this small story to the field of mobile devices means, that use of technology never seen before can result in huge success or a big failure - depending on the possibilities and the point of view from where we are looking at them.

The world of mobile development has plenty of developers: lots of companies are trying to make the „ultimate” application, the „million-selling” game, or just simply earn the day-by-day living. Coming out with new ideas is not only hard but dangerous, as nearly all ideas has been explored before – and maybe some of them just left behind having no sense at all.

We are a newly established company made by game industry veterans with plenty of experience in the entertainment industry. We decided to give mobile device users brand new experiences using the possibilities and the technologies incorporated in their devices. Our first family of products uses the accelerometer in an innovative way, giving newly discovered experiences to the users - for example that given feature of the mobiles is rarely used nowadays.  The name of the family of products is Fun Steps... and as a small demonstration here we go with the promotion video of it: (the important part begins at 00:30 :)) http://www.youtube.com/watch?v=8ZLtpvMUc0Q

First step having fun

This app covers a motion detection toy that is used to replace the normal walking sound of a person with different sound effects from dino crushing to robot bashing. Our goal was to make human walking humorous or scary (like in the Police Academy movies using the incredible voice talents of Michael Winslow). The result is better, than expected: we explain it later!As the lead programmer of Fun Steps project I help you to understand the difficulties and the happiness to make a game based on motion detection and on technological principles. Maybe the idea is not very complicated, but the technology behind is worth the development.



Quick and accurate step detection - the first Challenge

You can download a lot of step counting applications from different stores, so anyone can think, that detecting a step is a well-documented feature. The reality is that this particular task made us sweat a lot, as motion detection in real time is a lot more complicated then counting the steps.
 
In the case of a step counting program it’s enough detect the fact of the step: it’s not necessary to obtain the exact timing of step. In our case the most important part of our application is that we start the sound as close as we can, when the user’s leg touches the ground.For realising our idea we could not use complex algorithms, because of the expected delay of the processing. So we decided to use a simple method to detect the step. It detects the change of the amplitudo that is relative to an absolute threshold. This selected approach caused some problems at the beginning, but after further refinement it can produce a lot of good results, but requires a sensitivity option on the interface. It can be adjusted by the user to balance the exact force that is detected by the system as a step, so the application is able to detect the steps of small, big, fat or skinny people using whatever shoe they use from softer ones to hardest ones.

Some problems to resolve on Android - the second challenge

For technical reasons the audio latency is bigger issue on Android, so the problem persisted heavily.Also a lot of trouble has been caused by the different quality accelerometer parts used by different manufacturers. We discovered that some devices’ well-functioning settings are continuously detecting movement on other devices – even in non-moving state! Then we developed a test application to merit the noise level of the accelerometers in a quiet state. The results where extreme: we experienced 200-300% difference between mobile devices. 



We decided to throw away sensitivity for getting more rounded results on noisier devices.Another issue emerged also: it was hard to detect and when the measurements showed the facts it was hard to believe: some manufacturer’s devices speakers caused serious problems with the accelerometer of that device. And this is not a common mechanical feedback, but some electromagnetic distortion. For example some devices tested by us were able to detect an acceleration of 2G only because for their speaker’s voice. Without telling actual models and names I can tell, that some well-known brand’s products were also included producing that kind of phenomenon.



 

 
 
Because of this construction error the only solution for the users of those devices is really simple: use the product with a headset or the game will be of no use - we call it personal fun!

Fun, as a testing factor

It’s not easy to test such kind of application. As it’s necessary to put it on the pocket, it’s really hard to debug the system, or to experience with different solutions. We then decided to begin to walk up and down patiently to record the data from the accelerometer – we recorded the metrics to use and analyze them later on (and to simulate walking, of course). It was enough in the first phases of the development...… but during the final tuning we needed to walk great distances in our office making other people laugh and confusing our poor house animals and pets (not any of them has been harmed during development :)).

Success is fun!

After so many try-outs and testing the product took shape and all of us were very proud of it not just for the solution to the problem, but mainly because for the very new experience we created to the players. And that experience is a lot more fun as we originally expected. 
 
We gave our test versions to our family members and to the members of the press and got some really incredible feedback:

“When I’m with my friend and we start Fun Steps we end laughing on the floor.”

“Firstly I used it in my pocket emitting some scary sounds. It was fun, but then I got a small Bluetooth speaker and the REAL fun begun!!!!”

“It’s so funny when I sit my 1.5 year old children in my neck and we begin to walk around, like a frog or a clown. He is so cute laughing!”

“in a party, where several copies of Fun Steps were present the people organized a special Fun Jumping compo - not only the voice but a ‘kind of choreography’ was important too resulting in very funny sound effects”

„I’m a big, fat guy, so walking like a 6 ton mech was no concern to people – they thought I have mechanical legs. It was fun”



All those feedbacks made us very-very excited and proud after all that problems and sleepless nights the development caused.Fun Steps is a very nice toy. And it can be used even for love purposes, as seen in the Official video of Fun Steps: Beautiful girl, nerdy guy trying to conquest her - quite usual situation, but quite unusual solution with the use of Fun Steps!. As we like our video, we call your attention to it the second time - the video can be watched at: http://www.youtube.com/watch?v=8ZLtpvMUc0Q

Mobile devices still having a lot more potential to explore 

The technological explosion leading to today’s mobile devices happened very short time ago, so those devices still possess a lot of undiscovered, or not used features (don’t forget, user groups still find undocumented features for the Commodore-64 still in 2012!!!). To full spectrum use of those features is not happening from day to day - it needs a lot of pioneers and a lot of effort.

 The companies, leading the mobile revolution (like Apple or Google) must be open minded for those revolutionary efforts - it’s never known which experimental project will be the new “wonder”. And any of those experiments can find a common use broadening the palette of the applications and the possibilities of the use of mobile devices.

 

An example for the stories we got from our player:I got an email from Ohio, US, where a user, called Timothy trained his dog to recognize several Fun Steps voices as different commands. For example if they went to walk, or the dog needed to do some task, like go slowly, or near to it’s owner etc... This is such a different experience, that neither we visioned it as a possibility.Of course, it must be some unsuccessful ideas or experiments around, but the success compensates us for all the efforts we made. We encourage all developers to pushing the boundaries of the modern mobile devices, because the possibilities are nearly limitless.If you have any questions regarding the article, contact us:[email protected]