ESP32-S3 Wi-Fi Smartwatch Platform
Complete custom smartwatch firmware for a US client — analog and digital watch faces, audio playback, photo display, countdown timers, and full Wi-Fi remote control — evolved across four hardware generations in an ongoing collaboration that began in 2023.
Project Overview
What started as firmware for a single Wi-Fi-controlled watch has grown into a smartwatch platform spanning four display generations — from a 1.69" touch LCD through 1.75" and 2.06" AMOLED rounds to a 3.5" panel — with one firmware architecture carried and adapted across all of them.
The watch renders analog and digital faces with live battery state, countdown timers, and network status; plays audio through a dedicated driver; displays user photos; and is fully controllable over Wi-Fi — a built-in web page and REST API handle photo uploads, clock sync, and settings from any browser, with no app required.
Engineering Highlights
- Four hardware generations, one architecture — display, touch, power, and RTC drivers isolated so each new board is a port, not a rewrite
- Wi-Fi remote control — embedded web UI + REST API for photo upload, RTC sync, and power settings
- Audio playback — custom audio driver for music playback on the wearable
- Memory-smart photo rendering — JPEGs decoded block-by-block straight to the display, using ~512 bytes instead of a 134 KB framebuffer
- Real power management — AXP2101 PMIC integration, battery gauging, sleep timeouts, and thermal-safe peripheral handling
- Professional documentation — full technical manual and setup guide, so the client can build and flash independently
Outcome
The collaboration has continued for over two years and is still active — the strongest endorsement a client can give.
★★★★★"Tehsin is great to work with and is a very skilled engineer. I look forward to continuing to work with him in the future."