Interface · mod

Kronograf: aviation firmware for the T-Watch 2020

A from-scratch firmware for the LilyGO T-Watch 2020 with an aviation chronograph face, Back to the Future time circuits, bus departures, iPhone notifications and a network toolbox on the wrist.

Build sheet

Device page: LilyGO T-Watch 2020 →

Can I build this?Beginner · AI 5/5 · $25–40

Difficulty: Beginner
AI-buildability: 5/5
Time: A few weeks
Cost: $25–40

Parts

ESP32 1.3in SH1106 128x64 OLED

Tools

PlatformIOUSB-to-serial adaptermacOS with SDL2 and CMake for simulator

Starter prompt

Based on "Kronograf: aviation firmware for the T-Watch 2020" on Afterware: https://afterware.xyz/p/kronograf-aviation-firmware-for-the-t-watch-2020

I have a LilyGO T-Watch 2020 V1 with an ESP32 and a 240x240 ST7789 display. Using PlatformIO and LVGL 8, write a watch firmware with a swipeable analog chronograph face showing the time and battery level, and a second face with a dark red time-only layout. Read the accelerometer for wrist-raise wake and keep the code split into hardware abstraction and UI modules.

Estimates based on the original write-up. How AI-buildability is scored. Building with an AI assistant? Connect it to Afterware (free MCP server).

Story

Kronograf replaces the stock software on the LilyGO T-Watch 2020 with a firmware written from scratch on LVGL 8.3 and ESP32. The watch gets three faces, including an aviator chronograph and a "time circuits" face with three 7-segment rows, plus a launcher of nine-app pages drawn like sub-dials.

Beyond the faces, the firmware adds weather from Open-Meteo, real-time STM bus departures from a GTFS-realtime feed, iPhone notifications over ANCS with clear and decline actions, and a network toolbox covering Wi-Fi analysis, ping, traceroute, LAN scan and speed test. A TV remote uses the watch's infrared LED.

The project also includes a macOS simulator that builds the same interface, so screens can be checked and screenshotted without the hardware. Prebuilt binaries are published on the release page.

Resources · 3

Repository Releases (prebuilt firmware)My-TTGO-Watch