{"id":8824,"date":"2022-04-03T08:57:54","date_gmt":"2022-04-03T12:57:54","guid":{"rendered":"https:\/\/dronebotworkshop.com\/?p=8824"},"modified":"2023-04-11T14:45:02","modified_gmt":"2023-04-11T18:45:02","slug":"esp-now","status":"publish","type":"post","link":"https:\/\/dronebotworkshop.com\/esp-now\/","title":{"rendered":"ESP NOW – Peer to Peer ESP32 Communications"},"content":{"rendered":"\n

\"Download<\/a> \"Parts<\/a> \"View<\/a> \"Download<\/a><\/p>\n

Today we will be working with ESP-NOW, a connectionless protocol developed by Espressif for the ESP32 and ESP08266 microcontrollers. With ESP-NOW we can build a private network without WiFi or a Router!<\/span><\/p>\n

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Introduction<\/span><\/h2>\n

The ESP32 and its cousin, the ESP8266, are undoubtedly remarkable microcontrollers. Aside from a high-speed 32-bit architecture, they also have built-in Bluetooth and WiFi.<\/span><\/p>\n

The Bluetooth and WiFi capabilities on these devices are made possible by an integrated 2.4GHz radio transceiver module. And this module can also be used for other communications applications that use the unlicensed 2.4GHz band.<\/span><\/p>\n

Espressif, the makers of the ESP8266 and ESP32, have developed a protocol that allows all these devices to create a private, wireless network using the 2.5GHz transceivers. This is a separate network from the WiFi network and can only be used by ESP-type microcontrollers.<\/span><\/p>\n

The protocol is called ESP-NOW.<\/span><\/p>\n

ESP-NOW<\/span><\/h2>\n

ESP-NOW<\/a> allows simple packet communications between ESP devices, using the 2.4 GHz band. These transmissions operate a lot like those used by wireless mice and keypads and are limited to packets of 250 bytes or fewer.<\/span><\/p>\n

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Yes, I said 250 bytes!<\/b> Not quite enough for voice and video perhaps, although there are ways of packetizing both of those, but quite sufficient to deliver remote control commands or data from sensors.<\/span><\/p>\n

The data can be unidirectional or bidirectional, i.e. single-duplex or full-duplex. Most data types are supported.<\/span><\/p>\n

Data can be encrypted or unencrypted, and no external source of WiFi or a router is required. Depending upon your configuration, you can have anywhere from 2 to 20 devices communicating between themselves.<\/span><\/p>\n

The range can vary dramatically due to the environment, but under the right conditions (and with proper antennas) you can achieve over 400 meters. Just using the built-in antennas on the modules should still allow you to communicate through a medium-sized home without a problem.<\/span><\/p>\n

ESP-NOW Networking Modes<\/span><\/h3>\n

You can place your ESP-NOW network in many configurations. You can mix and match ESP32 and ESP8266 devices within the same network.<\/span><\/p>\n

Initiators and Responders<\/span><\/h4>\n

A device participating in an ESP-NOW network can be operated in one of two modes.\u00a0<\/span><\/p>\n