Hello, my name is Jasper de Winkel and today I'm going to talk about our recent work, the Battery-Free Game Boy.
Currently, most mobile systems include batteries,
batteries are costly, they are polluting the environment if not properly recycled,
and eventually must be replaced or, otherwise, the entire device might end up at the landfill altogether.
So one research direction, called intermittent computing, focuses on removing batteries from these devices
and replacing them with harvested energy.
So, these devices only operate on harvested energy and even the harvested energy can be volatile in nature.
So this leads to frequent power failures on these devices.
And within this research direction, we've come up with new methods of saving the state of the system
upon the power failure and then restoring the system state when enough energy is available.
So we were thinking, what can we do to push the boundaries of these devices?
Could we for example, make a more complex system such as a Battery-Free Game Boy?
Well, it turns out: Yes, we can!
So in this work we introduce (in our opinion) the first the battery-free handheld gaming console.
Of course, you can play games on it. But you can do so much more!
It could serve as a tool for studying interactive behavior of people with intermittent systems.
In order to make it work, we needed two key things.
That is: a new type of state saving and restoration system, called a checkpointing system.
One of the unique features of this system is that it only checkpoints,
the volatile memory that's actually used during operation.
So, if the memory is not touched during that power cycle it does not get checkpointed, saving time (of course) in the checkpoint.
And secondly, we introduced a new platform we call ENGAGE.
This platform not only harvests energy from light,
but it also harvest energy from the button presses of the user.
So actually user contributes to the power of the console.
To show how the system works,
here you can see, that the system harvests energy from light and from the button presses.
And as an example, Tetris is shown.
So you start playing and all of a sudden there is a power failure,
but during the power failure,
energy is harvested and then before the power failure, the system state is saved.
And just after the system resumes, the state of the system is restored.
So that's the game resumes in exactly the same position.
this basically means seamless transition from before to after the power failure.
We have evaluated the system in subparts,
(so each specific part of the system on its own),
but we have also done end-to-end evaluation.
So we actually played games on the console.
On the screen now you can see the actual screenshots of one of these game runs
and how the system behaved during that portion of gameplay.
You can see the voltage of the storage capacitor going up and down,
and the system harvesting energy,
and starting to checkpoint when a critical voltage on the storage capacitor is reached.
for further details on how the system works I would refer to the paper,
but I want to highlight two key aspects:
The ENGAGE the platform is more than 20 times, more power efficient than the original Game Boy,
and that is with full emulation of the Game Boy processor.
And our MPatch checkpoints are on average two times faster compared to naive approach.
Because we only checkpoint the memory that has been touched during the execution periods between power failures.
So, concluding, we today presented a new system, a Battery-Free Game Boy,
and a new platform called ENGAGE,
that demonstrates the possibility of battery-free gameplay despite frequent power interrupts.
We propose this system as a tool for further research on human interaction with intermittent systems
because, in our opinion, this still requires some attention.
Thank you very much for listening.
and please, if you're interested, have a look at the paper.
Thank you very much.