Meshtastic - Heltec T114 V2 With GPS And CardKB

Fully standalone Meshtastic/MeshCore radio based on the Heltec T114 V2. It features a built-in GPS module, CardKB keyboard, powerbank module with 22.5W fast charging, and is powered by three 18650 batteries.

This project is based on the components listed in the BOM.

Wiring diagram:

Battery tray + → Powerbank module +

Battery tray - → Powerbank module -

Powerbank module + → Heltec PCB +

Powerbank module - → Heltec PCB -

CardKB SDA → SSD1309 SDA

CardKB SCL →  SSD1309 SCL

SSD1309 SDA → Heltec PCB Pin 0.16

SSD1309 SCL → Heltec PCB Pin 0.13

CardKB + → Heltec PCB 3V3

CardKB - → Heltec PCB GND

Connecting the CardKB directly to 3V3 can drain the battery. This can be improved by using a transistor to switch the keyboard on only when needed, for example when the screen is on. 

This project can be complex. I have included some assembly photos below. If you have any questions, feel free to ask.