When Is a Badge Not Just a Badge? When It's the DCFurs DEFCON 2020 "Boop Blocker" Mask Badge!

FPGAs offer us a lot of reconfigurable silicon fun. They are powerful tools that allow designers to very create finely tuned data processing systems in hardware, capable of running at blazing speeds.

Alternatively, they can offer designers a swiss army knife of implementation, a toolbox that can contain whatever tools needed for the task at hand, merely by loading an alternate bitstream (the code that configures the FPGA), in order to specify the system function.

When it came to designing their badge for this year's DEFCON, the DCFurs team chose to implement their badge magic using an FPGA, and the results speak for themselves!

Taking the less conventional format of a mask, to be worn over a N95 or similar, this "badge" is a technical feat to behold!

Beyond the incredibly eye catching array of 256 RGB LEDs, the Boop Blocker mask hides a complete FPGA implementation — capable of driving complex patterns from memory, or even generating animations on the fly, in response to an audio input — the wearer's voice, for example!

But I can already buy that...

Having echoed similar thoughts, let me stop you there. No, this mask is one of a kind!

I recently lost a battle against my impulse control, and picked up a similar looking flexible PCB from "the usual suppliers," and while it's a neat toy, it simply can't compare to what the DCFurs team are working on here!

Limited by components chosen for basic function, the display shown above is a basic affair, and can only run basic, blocky, preconfigured animations on a fairly large pixel pitch.

Not to mention, the rectangular aspect ratio and gridded pixel alignment mean that it's much more suited to folding around a cylinder than the complex geometry of a human face!

The DCFurs team have created a device that addresses the issues listed above in style!

This "badge" is comprised of a flexible PCBA, some 200mm x 85mm, which is cleverly laid out in order to be amenable to being flexed in multiple axes — something really very important for a device that is going to see a fair bit of movement and flex as the wearer talks to people — something we are sure they will have to do in order to answer all the questions of "what magic is this?!"

You're as cold as iCE...

The FPGA that controls the core of this CoVID catcher is the community favourite — the iCE40 from Lattice Semiconductor, and it's been put through its paces here, with barely a bit of system resource left unused!

Within this table of resource allocation, sits an entire RISC-V soft CPU implementation, a block of SRAM, along with a touch of ROM, leaving enough logic left over to throw some neat gamma correction at the LEDs.

Gamma correction — often overlooked in lighting applications — is a correction factor that can lead to a more linear "appearance" to the brightness of a LED. It in effect compensates for the very non-linear response to light that is exhibited by the human eye.

On top of preconfigured LED animations, the DCFurs team have also implemented a bit of a more real-time functionality, with the mask having the ability to respond to audio, sampled through an on-board microphone. This feature shows off some of the DSP IP functionality within the iCE40 part. That's very cool!

With the schematic soon to be released — the hardware files look to be kept as closed source. We can understand that, as the DCFurs team is treating this hardware as a fundraiser.

Perhaps it will be opened up in due time, but for now, get your hands on one of these incredible masks by pledging a donation over on the DCFurs page here!