Messaging Library for ESP32/ESP8266 Devices

Introduction

ESP-messaging is a library for sending and receiving messages between ESP32/ESP8266 devices using ESP-NOW or UART. It allows a user to send JSON messages between devices, abstracting the underlying configuration, communication, and parsing of messages.

Features

• Separate threads (RTOS tasks) for sending and receiving messages
• Message queueing for inbound/outbound messages
• Automatic configuration of ESP-NOW and UART
• Automatic parsing of incoming messages
• Pass messages to user-defined callback functions
• Use one or both communication methods at the same time

Installation

ESP-IDF: Add the header and source files to your components folder.

PlatformIO: Add the url to the repository to your lib_deps in platformio.ini.

Usage

See messaging.h for a full list of functions and their documentation.

#include "esp-messaging.h"

void myMessageHandler(cJSON* incomingMessage) {
    // Handle incoming message
    printf("Incoming message: %s\n", cJSON_Print(incomingMessage));
    free(incomingMessage);
}

void app_main() {
    // Setup messaging for ESP-NOW
    setupESPNow(myMessageHandler);

    // Setup messaging for UART on GPIO17 (TX) and GPIO16 (RX)
    setupSerial(myMessageHandler, 17, 16);

    // Create message
    cJSON* message = cJSON_CreateObject();
    cJSON_AddStringToObject(message, "message", "Hello World!");


    uint8_t* broadcastAddress = calloc(6, sizeof(uint8_t));
    memcpy(broadcastAddress, "\xFF\xFF\xFF\xFF\xFF\xFF", 6);
       
    // Send message to all devices
    sendMessageESPNow(message, broadcastAddress);
    free (broadcastAddress);
}

Requirements

• ESP-IDF + FreeRTOS
• cJSON
• At least 2 ESP32/ESP8266 devices