IOTMP Client for ESP-IDF

IOTMP protocol client component for ESP-IDF (v5.x/v6.x). Connects ESP32 devices to the Thinger.io IoT platform using the IOTMP binary protocol.

Built on the shared IOTMP-Embedded core library (same protocol engine used by the Zephyr and Arduino clients).

Features

• TLS-secured connections via esp_tls (enabled by default)
• Dedicated FreeRTOS task with select()-based event loop
• Thread-safe server API (properties, buckets, endpoints) callable from any task
• Automatic reconnection with exponential backoff
• Resource streaming with configurable intervals
• Full Kconfig integration for compile-time configuration

Quick Start

1. Project Structure

your_project/
├── main/
│   ├── CMakeLists.txt
│   └── main.cpp
├── CMakeLists.txt
├── components/
│   ├── iotmp-espidf/      (this component)
│   └── iotmp-embedded/    (core protocol library)

Or set EXTRA_COMPONENT_DIRS in your project CMakeLists.txt:

cmake_minimum_required(VERSION 3.16)

set(EXTRA_COMPONENT_DIRS
    "/path/to/iotmp-espidf"
    "/path/to/iotmp-embedded"
)

include($ENV{IDF_PATH}/tools/cmake/project.cmake)
project(my_thinger_project)

2. Code

#include <thinger/iotmp/client.hpp>

// After WiFi is connected...
static thinger::iotmp::client thing;
thing.set_credentials("username", "device_id", "device_credential");
thing.set_host("iot.thinger.io");

// Define resources
thing["temperature"] = [](thinger::iotmp::output& out) {
    out["celsius"] = 23.5f;
};

thing["relay"] = [](thinger::iotmp::input& in) {
    bool state = in["on"].get<bool>();
    gpio_set_level(RELAY_GPIO, state);
};

// Start (creates a FreeRTOS task)
thing.start();

3. Build & Flash

idf.py build
idf.py flash monitor

Kconfig Options

Configure via idf.py menuconfig under Thinger IOTMP Client:

Option	Default	Description
THINGER_IOTMP_STACK_SIZE	8192	Client task stack size (bytes)
THINGER_IOTMP_PRIORITY	5	Client task priority
THINGER_IOTMP_KEEPALIVE_SECONDS	60	Keep-alive interval
THINGER_IOTMP_MAX_MESSAGE_SIZE	4096	Maximum IOTMP message size (bytes)
THINGER_IOTMP_TLS	y	Enable TLS (port 25206) or plain TCP (port 25204)
THINGER_IOTMP_RECONNECT_BASE_MS	1000	Initial reconnection delay
THINGER_IOTMP_RECONNECT_MAX_MS	60000	Maximum reconnection delay

Server API

The server API methods are thread-safe and can be called from any FreeRTOS task:

// Properties
thing.set_property("config", json_t{{"threshold", 42}});
json_t data;
thing.get_property("config", data);

// Data buckets
thing.write_bucket("sensor_data", json_t{{"temp", 23.5}});

// Endpoints (email, webhooks, etc.)
thing.call_endpoint("alert");
thing.call_endpoint("notify", json_t{{"message", "hello"}});

// Manual streaming
thing.stream("temperature");

Dependencies

• IOTMP-Embedded — shared protocol core
• ESP-IDF >= 5.0

Documentation

• Thinger.io Documentation
• IOTMP Protocol

License

MIT License - Copyright (c) INTERNET OF THINGER SL