OpenTrailPaper is an open-source, DIY e-paper bike computer project comprised of firmware for the ESP32-S3-based T5 E-Paper S3 Pro devkit and Android and iOS companion apps for maps, routes, and settings.It shows ride data and offline maps, follows standard GPX (GPS Exchange Format) routes, records FIT (Flexible and Interoperable Data Transfer used in Garmin devices) files, and connects to Bluetooth (and soon ANT/ANT+) heart rate, power, and cadence sensors.Before looking into the project’s details, let’s check out the LILYGO T5 E-Paper S3 Pro specifications:

ESP32-S3-WROOM-1 wireless module

SoC – ESP32-S3N16R8 dual-core Tensilica LX7 microcontroller @ up to 240 MHz with

2.4 GHz 802.11n WiFi 4 and Bluetooth 5.0 LE connectivity

Memory – 8MB PSRAM