Build an IoT countdown clock using Adafruit QT Py ESP32-S2, alphanumeric STEMMA QT displays and CircuitPython! 

The alphanumeric displays text that scrolls the time remaining until your next exciting event!

This uses three alphanumeric displays daisy chained together using I2C STEMMA QT cables.

The electronics are housed in a 3D printed stand that snap fits together for any easy assembly.

Necessary Hardware

The following hardware is needed to complete this project.

QT Py ESP32-S2 Microcontroller

You need only one of the following boards.

Angled shot of small square purple dev board.
What has your favorite Espressif WiFi microcontroller, comes with our favorite connector - the STEMMA QT, a chainable I2C port, and has...
Out of Stock

Quad Alphanumeric Display STEMMA QT Backpacks

This project requires three alphanumeric display backpacks and three pairs of the alphanumeric displays. The backpacks are bundled with the displays.

The bundles are available with displays in red, green, blue, white, and yellow. Only blue is included below. Check the Featured Products on the right side of this page to find links to the others.

Overhead video of an assembled 14-segment LED backpack, emitting the follow text in blue LEDS: "AdaFruit 14-Segment Backpack"
Display, elegantly, 012345678 or 9! Gaze, hypnotized, at ABCDEFGHIJKLM - well it can display the whole alphabet. You get the point. This is a nice, bright alphanumeric display that...
Out of Stock


You will need three of the following cables.

Any length will work, but the 50mm cable is the best option because it leaves the least amount of excess cable behind the displays.

Angled of of JST SH 4-Pin Cable.
This 4-wire cable is 50mm / 1.9" long and fitted with JST SH female 4-pin connectors on both ends. Compared with the chunkier JST PH these are 1mm pitch instead of 2mm, but...
In Stock


To power the project, you can use a USB C cable plugged into a USB battery or a USB port on your computer.

Angled shot of coiled pink and purple USB cable with USB A and USB C connectors.
This cable is not only super-fashionable, with a woven pink and purple Blinka-like pattern, it's also made for USB C for our modernized breakout boards, Feathers, and...
In Stock
Angled shot of a blue long rectangular USB battery pack.
A smaller-sized rechargeable battery pack for your Raspberry Pi or Raspberry...
Out of Stock

This guide was first published on Dec 20, 2022. It was last updated on Feb 27, 2024.

This page (Overview) was last updated on Dec 09, 2022.

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