T.A.S.C. Take A Sip Coaster

If you have ADHD, you often forget to drink water regularly. This can quickly become a vicious cycle that’s unhealthy for both your body and your mind. Staying hydrated is crucial, so to help myself remember and make the process a bit more fun, I built the T.A.S.C. (Take A Sip Coaster) for my office desk.

Technical Breakdown

The coaster is USB-C-powered and features an integrated IR transmitter and receiver diode. It detects when a bottle is placed on the surface, which automatically triggers a 15-minute timer.

The feedback loop is broken down into three stages:

At 5 minutes: The LED ring briefly flashes yellow.
At 10 minutes: It flashes cyan.
At 15 minutes: The ring alternates between red and blue, and the coaster vibrates three times.

The flashing continues until the bottle is removed. Once you take a sip and place it back, the timer restarts. Simple, visual, and effective.

The “Why”

I know I could just use a phone app, but for someone with ADHD, touching your phone is a total trap. One notification leads to another, and before you know it, two hours have vanished and you’re still thirsty. The T.A.S.C. keeps me focused on the task at hand: staying hydrated without the digital distractions.

Parts

1 ESP32 C3 mini
5 WS2811b LED’s
1 940nm IR tx diode
1 940nm IR rx Photodiode
1 Resistor 150R
1 Resistor 2K2
1 Resistor 100K
1 1n4148
1 BC815
1 Pager Motor

Schematic

I know the ESP is overkill, but I just happened to have it on hand. It’s throttled to 20 MHz, which is more than enough.

Software

https://github.com/awall9999/T.A.S.C.

The enclosure

For the top and bottom sections, I chose 3mm black plexiglass, and for the middle section, 5mm clear plexiglass. A hexagon shape was laser-cut out. A 1mm-thick piece of acrylic was used to cover the USB-C port. Six M4x10mm sleeve nuts and sleeve screws were used to connect the parts.