There are (were) 0 days until MBBS: a joke countdown trinket

I made a circuit board trinket as a joke present for my classmates on a whim. It turned out pretty well.

The story

The 4 and a half year university course that I recently graduated from culminates in a big certification exam including a practical component dragged across two weeks. Students are generally very stressed out by this^{[citation needed]} because of the breadth of content involved as well as the unpredictability of the practical exam.¹

A year before the final exams were going to happen I thought it would be funny to start counting down to D-day. Rather than trying to shop for countdown apps or widgets², I decided that I might as well DIY. The result was a cron job that triggered a countdown message everyday at noon delivered via a telegram bot.

Over the course of a year classmates would trickle in and out of the group chat containing these bot reminders; the bot peaked at sending countdown numbers to around one quarter of the entire cohort every day at noon like clockwork.

Then there were 100 days left, then two months, then a month…

The idea

I would be lying if said I didn’t feel bad for lightly torturing my classmates over the past year. With around 20 days left on the countdown I decided to look for a more wholesome yet in-character way to end off the countdown.

I decided to draw some inspiration from various competition coins and hardware conference badges I’ve collected over the years. The latter are often circuit boards with intricate designs which try to be both eye-catching and yet useful in some way.

Compared to printing keychains made of acrylic / wood / fabric, PCBs designs are typically limited to using a palette of at most 4 to 5 distinct colors by varying what materials (soldermask / silkscreen / copper) are applied to the circuit board. Exposed copper even gets a silver or gold metallic finish as part of the fabrication process. And heck circuit boards just look cool.

For my purposes a small circuit board trinket would do the trick, though given the time constraint I wouldn’t have the bandwidth to prototype and make something functional. I managed to hammer out this design in a few hours while procrastinating from hitting the books:

The design contained:

• A total board footprint of 31mm x 31mm
• Purple soldermask (in school colors) as a background
• A skull icon in white silkscreen, traced off twemoji’s skull which was used for the bot’s profile photo³
• Text in white skilkscreen and Renogare typeface
  • The first line was written in the style of the bot’s countdown messages
  • The second line and choice of font was a throwback to one of my favourite video games
• Exposed copper/gold metal accents elsewhere
• A 3.5mm diameter / M3 mounting hole to pass a keyring or clasp through

The execution

Ordering the PCBs off the internet from JLCPCB was a rather smooth experience. I needed to specify a few technical fabrication details inside the order, such as opting for gold-plating and high precision printing options. These bumped up the cost a fair amount but it was still managable given a batch order of ~100 or more pieces. I sent off the order a bit past midnight and only a few days later they came in the mail!

I also ordered some lobster clasp straps off Aliexpress to pass through the trinket’s mounting hole. I wasn’t able to find a sizing chart for any of the sales entries, so it was a gamble if it would fit and thankfully they did.⁵

Once the trinkets were assembled and packed into envelopes, distribution started on Jan 2nd with instructions to only open them when the bot ticked down to “0 days left” on the day before the papers began.

The review

Whoever is holding on to these trinkets, I hope I didn’t traumatize you too much and I also hope that you at least got any bit of a laugh out of this joke that I put a little too much effort into. Thanks for staying for the ride and here’s to surviving whatever happens after school.

Last off, I’d like to give a shout out to Jed, Sandy, Austin and everyone else who I studied together with in the lead up the exams; I couldn’t have done this without you.