9

FIELD TEST

ELECTRONICS
At the heart of the board is a GD32F150 which,
according to the datasheet, is a 32-bit ARM Cortex
M3 microcontroller running at 72MHz – quite a bit of
power for a badge! We tested the badge with Linux
and it identifies as an STM32-compatible board, which
means we have access to the full GPIO of the badge,
so we can easily re-flash it using the Arduino IDE – if
you’re brave enough! There is also 64kB of flash
storage and 8kB of SRAM on the board, but another
chip just above the GD32F150 is the P25Q16H, for an
additional 2MB of flash storage, which is used when
the badge is connected to a computer. It stores the
manual and Windows drivers for the board.

SOFTWARE
To program the badge, there is a Windows
application. Sadly, there are no macOS or Linux clients
but, as mentioned earlier, eager Arduino hackers can
program the badge in that manner. We also tried
using the Windows for Linux wrapper Wine to run the
application, but sadly this did not work.
The application may not win any awards for style,
but it works and it can be used to create static or
animated designs featuring icons and standard ASCII
characters, which the clever hacker can use to create
animations for cosplay or integration into props. The
badge can store multiple animations and images,
which can be selected using a long press on the
brightness button. Flashing the badge is simple and
takes mere seconds.

CONCLUSION
This is an useful piece of kit. For the most basic use,
this is a great conference badge that will give a full
day of use from one charge. Taking it up a notch, we
can easily add this board to cosplay and props thanks
to its small size and easy-to-access power/battery
connections. The small size is also a bonus for 3D

printing enclosures, to mask the badge and help it

blend into your creation. For the advanced hacker, we

have a powerful STM32-compatible microcontroller

that can be used to power much more than the

LED array.

We tested this badge at two events and it

performed admirably. In fact, it drew plenty of

attention, with many asking where to purchase it.

Now, we purchased ours from Amazon, but the

identical item is available via eBay for less than half

the Amazon price!

No matter what you may use this for, this is a very

hackable piece of kit that will offer many different

options for all levels of makers.

Happy hacking!

OTHER OPTIONS

There are alternatives to the conference badge that we took apart, and they range

in price and dimensions but are all viable, depending on your budget and skill. For

those who want a drop-in board, the Inky pHAT board from Pimoroni is a Raspberry

Pi-compatible board that offers an E Ink display, which only uses power when updated.

The Inky pHAT comes in black and white; yellow, black, and white; or red, black, and

white. It can display text and graphics. The screen update time is slow, so no fast-

moving graphics, but it is a viable option for a simple conference badge.

Those of us who have a budget can use LED arrays, typically controlled using the

MAX7219 controller. These work with the SPI interface, and it means they can be used

with Arduino, Raspberry Pi, and micro:bit.

Other alternatives are OLED screens. These are tiny and bright screens but often

less than an inch in size! OLED screens can be used with SPI or I^2 C interfaces, so again

they can be used with many different microcontrollers.

The last alternative is firmly in the past, and it is the screen commonly found in late

1990s Nokia phones, such as the 5110. These screens are common on eBay and are

easy to work with for most microcontrollers. The only issue with these screens is that

their stock is dwindling, so buy one while you can!

Below

A lean LiPo battery,

which is replaceable

if you are careful,

powers the badge

for nearly a full

day of use, at

20% brightness

Above

It may not look like much, but it’s got it where it counts! The app

does an admirable job and is easy to use. We can also program

multiple animations for one badge