the Adventures of Sara Cladlow

I am Sara Cladlow, a social consultant working in Washington, DC. I provide consulting, social training, and event services for both corporate and political clients. I also accept contracts for security investigations requiring a subtle touch.

The 2022 eChallengeCoin is available on my Tindie store!

New for 2022 is an optional ruby red acrylic badge holder which is great for wearing at a conference or hanging the eChallengeCoin on display.

If you already have the 2022 eChallengeCoin (or not) and want to read the story, Sara and the Nightclub Riddler is now available online.

More About the 2022 eChallengeCoin

What's New

The new eChallengeCoin has six touch sensors and seven LEDs. The touch sensors are now more than twice the size of previous eChallengeCoins - each touch sensor is actually a pair of pads. This should help fit normal sized fingers! The buzzer has two volume levels - it's soft when powered by the battery and loud when connected with the 3V pin. The WAKE / SLEEP feature is now a push button on the top edge and the IR transceiver is on the side of the button. To activate the bonus you point the edge of your eChallengeCoin at another! The UART interface is now a staggard pin header with standard 0.1" spacing. The staggard design eliminates the need to solder pins.

The 3 interactive challenges are back but with a twist. The first challenge requires no skills what so ever ... wink wink. The first interactive challenge is so much fun it's also one of the three demos. It makes for a fun game to play with friends.

What's Familiar

The 2022 eChallengeCoin continues the tradition with the same 44mm diameter and 6mm thickness. The UART uses the GND, 3V, TX, and RX pins. (see the diagram for the layout or remove the backshell to see the printing on the PCB) It is set for 9600-8N1. It only outputs line-feed so you may need to configured your terminal to add the carriage-return. The puzzle may be powered using the 3V and GND pads. It will tolerate up to 3.3V.

The WAKE / SLEEP feature is now a button. Press the button to WAKE the eChallengeCoin. Press the button during a demo will put the puzzle back to sleep. You will know the puzzle has recognized the button when all LEDs flash once. Press the button during an interactive challenge's 'clue' phase will flash the LEDs and then immediately skip to the 'answer' phase and wait for the user input. This may be helpful when attempting a challenge again and it has a lengthy clue.

Some of the interactive puzzles have a long clue. If you already know the clue and just want to skip to providing the answer, you may use the wake button as previously described or you may touch all of the touch sensors together. You will know the eChallengeCoin has detected this when all of the LEDs are illuminated. Once you release all of the touch pads, the LEDs will go out and the eChallengeCoin will be ready for you to answer the clue.

When the eChallengeCoin wakes, it will show the current status. The status includes which interactive challenges have been solved, which story challenges have been solved, and if the bonus has been achieved. A solid LED means a challenge is completed and the next challenge is shown with a blinking LED. Touching any sensor will leave status mode and begin the next unfinished challenge. The eChallengeCoin will go to sleep after a challenge has been completed or failed. It will also go to sleep if idle for 60 seconds. The idle time is extended to 5 minutes when in story mode.

The interactive challenges use a combination of the touch sensors, the LEDs, and the buzzer. The layout of the LEDs use the left three LEDs to indicate the interactive challenges and the right three LEDs to indicate the stroy challenges. The center LED indicates the bonus. The touch sensors are labeled with 1..3 on the left and 4..6 on the right. The Touch-1 sensor corresponds to the top left LED and the Touch 4 sensor corresponds to the top right LED.

The 2022 eChallengeCoin has another story from the series the Adventures of Sara Cladlow. Within each story, you are tasked with solving the challenges Sara encounters. The story is accessed through the UART connection on the eChallengeCoin.

The demo of the eChallengeCoin are activated by touching opposing sensors while waking the puzzle. Once a demo has been activated, it remains active until it is deactivated - even though sleep/wake changes. To return to the challenges, touch any single sensor while waking the puzzle.

Hints, Clues, and Spoilers

Game #1 Hint:
There's nothing to do but start the challenge and hope you win
Game #1 Clue:
If your don't win on the first try, just wake the eChallengeCoin and keep trying
Game #1 Spoiler:
It's the game of Craps so you just have to keep trying until you get lucky
Game #2 Hint:
Have you looked at the text on the face of the eChallengeCoin
Game #2 Clue:
What year was the song released
Game #2 Spoiler:
The song is 'Call Me Irresponsible' sung by Frank Sinatra and released on his own album and performed as part of 'The Rat Pack, Live at the Sands' in '63 so you enter the digits with the touch sensors one at a time '6 3'
Game #3 Hint:
There are four colors used, one color is used a a lot less than the others
Game #3 Clue:
Have you looked at the UART output
Game #3 Spoiler:
You can capture the UART output and do a search-replace of RED for dit, GREEN for dah, BLUE for character breaks, and WHITE for word breaks. You end up with 'first name of the chairman of the board'. The answer is 'FRANK' which '..-. .-. .- -. -.-' and entered as 'LEFT LEFT RIGHT LEFT, LEFT RIGHT LEFT, LEFT RIGHT, RIGHT LEFT, RIGHT LEFT RIGHT'
Story #1 Hint:
Ignore all of the obvious words and numbers and looks at what's left
Story #1 Clue:
A popular deciphering technique is to looks for repeating letters. The two words use the same cipher but need to be deciphered independently
Story #1 Spoiler:
Using a Caesar cipher on 'HiTaap DeFotz' with an offset of 11 for the first and 15 for the second, you end up with 'stella studio' and the case is not important
Story #2 Hint:
Look at the words which stand out from the track list
Story #2 Clue:
Combine all of the all-cap words into a long string and try solve - remember this is a real place
Story #2 Spoiler:
The letters CARSTOURFEARTHERE are rearranged into terraceafterhours - which is a real after hours nighclub on the roof of the Larry Flynt's Hustler club - and spaced are ignored when entering the answer
Story #3 Hint:
Look a the whole message
Story #3 Clue:
Did you notice the phone number
Story #3 Spoiler:
The message came from (263) 333-7467 and when you take all the digits and use T9 texting, you end up with COFFEESHOP and case is ignored when entering the answer

eChallengeCoin Overview

eChallengeCoin Demos

eChallengeCoin Audio Boost

From the Desk of Sara Cladlow

September 30th

Triple Holder

Several people asked about the custom eChallengeCoin holder which can all three current eChallengeCoins - 2020, 2021, and 2022. While only one was made, the SVG file is available for download. It is suitable for laser cutting from 10mm acrylic.

August 10th


DEFCON 30 is the first time the eChallengeCoins have been available at the conference and it's all thanks to Hacker Warehouse. They are selling the 2022 eChallengeCoin with the badge holder in thier vendor booth!

February 15th

Countdown to Launch

The hardware is done. The software is done. The story is done. The labels are done. The cases are done. What's left? Nothing! The countdown to launch has begun! The current plan is to upload to my Tindie store in 75 days. Why 75 days? It's the first of May!

January 15th


The hardware is finished. The software testing has entered it final phase. It will be available on the Tindie store and if the virus gods permit it, they (the eChallengeCoins, not the gods) will be available at DEF CON 30!

January 1

Hardware Changes

The 2021 eChallengeCoin buzzer was not very loud. For 2022 the buzzer is a little better but still not loud but if you power the eChallengeCoin with the GND and 3V pins of the UART connection, it now gets much louder. Is it perfect? No. But it's better and we continue to experiment with new solutions.

Another significant design change is the UART connection. You no longer need clips around the edge. There is now a standard pin header along the bottom. The pins are staggard which should allow the use of 0.1" pins without the need for solder.

Hardware in KiCAD

As an experiment, the design files are viewable here using KiCanvas.