ESP-NOW is a connectionless communication protocol developed by Espressif that allows ESP32 and ESP8266 devices to communicate directly with each other without needing a WiFi router or access point. It's useful for low-power, low-latency communication between microcontrollers. Find out more details on Espressif's site here and check out their API documentation.

ESP-NOW creates a peer-to-peer network where devices can send data packets directly to each other using their MAC addresses. Devices can broadcast messages to specific recipients or to all nearby devices without needing any central infrastructure.

Give it a try -- it's great for props, sensor-networks, remote controls, and mesh communications.

Parts

You can use ESP-NOW in CircuitPython and Arduino on most ESP32, ESP32-S2, ESP32-S3 boards. ESP8266 boards also support ESP-NOW.

Here are some example boards, all of which can communicate with each other using ESP-NOW: