The Skull CTF

by Wokwi

A mind-bending hardware puzzle in three acts

View all updates Nov 05, 2020

Blessing the Bytes

by Uri Shaked

Ahoy Mateys!

[▓▓▓▓▓▓▓▓▓▓▓▓░░░] 81%

First and foremost, the firmware. We’ve summoned a shaman from the deepest, darkest jungles of a long-forgotten land, and she’s been working night and day, performing ancient bytecode incantations to bless our compilers.

Dark Rituals in Progress

During last night’s séance (conducted through zoom, of course), we were visited by a mysterious entity who gifted us with a pair of binary-encoded numbers that turned out to be a latitude and a longitude. Early this morning, we hired on with a crew of buccaneers, mutinied to gain control of their ship, and sailed her to those coordinates.

Diving into the sea, we found a locked chest and, inside it, two carefully typed scrolls containing some very cryptic code. We’re not exactly sure what it does, but we can tell—based on the author’s diabolical use of white space—that it comes from beyond the grave. Following widely recognized best practices, we decided to embed it into our firmware and hope for the best.

Before we could get started, however, our shaman issued a stern warning: to avoid a disastrous outcome, we must choose only one of the two scrolls and discard the other. Which is where YOU come in. We invite you to cast you vote and help us determine…

which piece of code looks more wicked!?


About the Author

Uri Shaked


$3,298 raised

of $666 goal

495% Funded! Order Below

Product Choices


The Skull

A single The Skull CTF board (☠)


SparkFun Programmer

From the Crowd Supply Basics project.

Design your own puzzles and load them into The Skull's brain using this programmer! Mini USB cable not included.

AVR Pocket Programmer by SparkFun


EconoStik Header: DR VT SMT 2x3

From the Crowd Supply Basics project.

Use with the SparkFun Programmer.

One Amphenol FCI EconoStik™ 2.54mm Header. SMD/SMT Mounting style, Straight angled male pins, gold-plating. Voltage rating: 110 V



Wokwi creates tools for the Arduino and maker community, such as AVR8js, the Open source Arduino Simulator, and GoodArduinoCode.

Uri Shaked

JA Electronics


PCB Fabrication & PCB Assembly

See Also

Subscribe to the Crowd Supply newsletter, highlighting the latest creators and projects: