Application | DIY electronic paper ink screen watch WATCHY

△The picture on the left is the modified version: Calculateur (Source: jochen)

Indifferent to these?

It doesn't matter, the developer has open sourced the model file for 3D printing, and users can customize the appearance of the watch they want.

Like these works in previous design competitions:

In addition, there are various styles of watch faces to choose from:

Many technical nerd netizens can't help but start, and many of them are hardcore players.

First of all, the developer chose the ultra-low power GDEH0154D67 as the screen, which is a 1.54-inch ink screen with a resolution of 200x200, using the SPI interface, and the price is less than 40 yuan.

Among them, the microcontroller selected is the Espressif ESP32-PICO-D4 module (the red part in the figure below), and the ESP32 chip integrates 2.4G wireless and Bluetooth functions.

Key hardware and features also include:

The USB to UART module CP2104 produced by Silabs (U3 below) is convenient for programming anytime, anywhere;

Ultra-small, three-axis, low-gravity acceleration sensor BMA423 (U4 below) for motion tracking and gesture detection;

The real-time clock DS3231 (U6 in the figure below), priced at about 20 yuan, supports calendar and alarm functions;

Mini Motor 1020 for Vibration;

4 tactile buttons K2-1114SA-A4SW-06.

200mAh 3.7V lithium battery 402030 and antenna SWRA117D.

Friends who want to start from scratch can view detailed materials through the chart list on the official website.

software part

Get the hardware part, it is necessary to solve the software solution.

The developer has encapsulated the framework used in Watchy.h, and the producer can get it from GitHub.

It also provides a simple C++ Arduino API that simplifies BMA423 sensor readings for orientation sensing and step counting.

The graphics display part uses GxEPD2, an Arduino display library for SPI ink screens that relies on the Adafruit GFX library for drawing images and text.

The timing part uses the DS3232RTC that supports the DS3231 real-time clock, also from Arduino.

The standard version of this watch is priced at $59, which is equivalent to less than 380 yuan. After assembly, you can get a wearable PCB watch (with tempered film).