espnow.h File Reference

ESP-NOW peer messaging with a typed envelope (PC_ENABLE_ESPNOW). More...

#include "protocore_config.h"
#include <stddef.h>
#include <stdint.h>

Go to the source code of this file.

Detailed Description

ESP-NOW peer messaging with a typed envelope (PC_ENABLE_ESPNOW).

Connectionless ESP32 peer-to-peer radio messaging (no AP, no IP) wrapped in a small typed envelope so a receiver can demux by message type and reject a truncated frame. Two layers:

• Host-testable core (pure): the 3-byte envelope codec (pc_espnow_encode / decode) and a bounded peer registry (PC_ESPNOW_MAX_PEERS, no heap). Same on host and ESP32.
• ESP32 binding (ARDUINO): pc_espnow_begin / add_peer / send / broadcast over the esp_now API, delivering decoded frames to a callback - which the application can bridge to WebSocket/SSE.

ESP-NOW's raw payload is capped at 250 bytes; the 3-byte envelope leaves PC_ESPNOW_MAX_PAYLOAD for data. No stdlib, no heap.

Author

Douglas Quigg (dstroy0)

Date

2026

Definition in file espnow.h.