Your ESP32 can talk to other ESP32s without a router, and it changes what you can build
Fewer middlemen, with a few catches.
Two ESP32 boards can communicate with each other without relying on a router, thanks to Espressif's ESP-NOW feature. This technology enables direct communication between multiple boards using MAC-based point-to-point (P2P) connections, bypassing the need for a traditional router or network association. To demonstrate the concept, a simple experiment was conducted using just two ESP32 boards and an LED ring.
One board, triggered by its onboard BOOT button, would send packet data to the other board, which would register and visually confirm each press using an LED. The communication was established using MAC addresses and never required Wi-Fi network association. In subsequent experiments, the concept was applied to a real-world use case involving sensor data collection and display.
Two boards were utilized: one to collect data using an AHT10 sensor and another to show the readings on a small OLED display. The sender board read temperature and humidity data from the sensor, while the receiver board displayed the information. Extensive testing in various scenarios, including different distances between the boards, confirmed that ESP-NOW maintained reliable communication without any packet loss.
However, when attempting to integrate ESP-NOW with internet connectivity or LAN access, additional testing is required. For instance, when one board joins a Wi-Fi network (router), it can still communicate with the other board as long as both are on the same Wi-Fi channel. If the sender board is placed on a different channel, packet loss may occur.
Despite the promising results, there are still areas to explore, such as encryption, real-world testing, and handling many-to-one sensor networks.
Written by urgent.news from XDA Developers's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
