The trickiest hurdle in this build was the real-time clock. The first module the maker tried simply refused to cooperate, and a shield pulled from an Odroid C2 single-board computer took its place. Even then, getting the clock talking meant putting it on its own I2C bus, on pins 16 and 17 if memory serves. Stubborn hardware conflicts like that stall plenty of first projects, and the maker pushed straight through it.
What emerged is a handheld called esp32mate, soldered onto a green perfboard around an ESP32 development board fed over micro-USB. It began life as a weather station running on a nano with an AHT10 and a BMP180 feeding a 16x2 LCD, then grew into something much bigger. Five tactile buttons went in where only two were originally planned, and that change redirected the whole project.
The feature list is strong for a first ESP32 effort. Temperature, humidity and pressure in hPa get plotted as trend charts covering the last four hours, with readings every five minutes and an hourly save to ROM. There is an Arkanoid game with score tracking, a Snake variant showing snake length, and a settings section covering unit switching, text entry for location and altitude, chart clearing and a full reset. Games, scrolling and text editing came out of AI assistance in a few hours, while navigation and page layout are the maker's own code.
Two things remain open. Dead pixel lines across the top of the OLED restrict use of the full screen, though the maker rates it as still plenty usable. And there is no power source beyond the USB lead yet; a battery with charging is on the wishlist.