ePaper Battery Weather Station ESP32

thingiverse

This is a simple snap-fit case for a TTGO ESP32 board with the 18650 battery holder (but no OLED). Only 3 M4 screws are needed to fix the cap (can be anything from 5 to 10mm long). The ePaper display can be a generic 2.9". I've used a GDEw029C32 from GoodDisplay (black, white, yellow) with their breakout board. Above all I've just made some aesthetic mods over the great firmware provided by G6EJD: https://www.youtube.com/watch?v=S-rqia4tIn4&t=22s Print the BODY and CAP, as showed in the images. All the needed supports are already built into the stl file. The TTGO boards unfortunately have a very inefficient 3V3 LDO to step down the 5V line coming from the good-enough integrated charger/step-up regulator. This limits the autonomy to about 6 days with 30minutes refreshes (going on also at night). Replacing the 3V3 regulator with a switching one, like a MagI³C-FDSM from Wurth, helped extending battery life to about 12 days. Unfortunately that's not much... maybe in future I'll design a dedicated PCB with all the needed tronics to try to reach several months of battery life... but let's see how it works!