This guide shows how to setup an HTTP communication between two ESP32 boards to exchange data via Wi-Fi without an internet connection (router). ESP32 Client-Server Wi-Fi Communication Between Two Boards.Add an OLED display, 18650 Li-Po cells, antenna and connectors and you can put it all together. At its heart is the ESP32 based TTGO T-BEAM V1.0 which has almost everything needed for this project.

Fully compliant with WiFi 802.11b/g/n/e/i and Bluetooth 4.2 standards, supports both Arduino IDE and ESP-IDF software development tools and keeps the same form of factors and pinout as the standard Arduino UNO R3 board. Another novelty, it is now possible to update in Wi-Fi the SPIFFS memory area. It is now possible to use the password hash to further secure the remote update.