IOTMP-Zephyr

IOTMP client module for Zephyr RTOS, enabling devices to connect to the Thinger.io IoT platform.

Built on the IOTMP-Embedded protocol core.

Features

• Dedicated client thread with poll()-based event loop
• Automatic reconnection with exponential backoff
• Keep-alive management
• Resource streaming (periodic and event-driven)
• Server API: properties, buckets, endpoints, device-to-device calls
• TLS support via Zephyr's mbedTLS integration
• Fully configurable via Kconfig

Quick start

1. Add to your west.yml

manifest:
  projects:
    - name: iotmp-zephyr
      url: https://github.com/thinger-io/IOTMP-Zephyr
      revision: main
      path: modules/lib/iotmp-zephyr

    - name: iotmp-embedded
      url: https://github.com/thinger-io/IOTMP-Embedded
      revision: main
      path: modules/lib/iotmp-embedded

2. Enable in prj.conf

CONFIG_THINGER_IOTMP=y

3. Use in your application

#include <zephyr/kernel.h>
#include <thinger/iotmp/client.hpp>

static thinger::iotmp::client thing;

int main() {
    thing.set_credentials("username", "device_id", "device_credential");
    thing.set_host("iot.thinger.io");

    // Output resource (sensor)
    thing["temperature"] = [](thinger::iotmp::output& out) {
        out["celsius"] = 23.5;
    };

    // Input resource (actuator)
    thing["led"] = [](thinger::iotmp::input& in) {
        bool state = in["state"].get<bool>();
    };

    thing.start();

    while(true) {
        k_sleep(K_SECONDS(5));
    }
}

Configuration (Kconfig)

Option	Default	Description
CONFIG_THINGER_IOTMP_STACK_SIZE	4096	Client thread stack size
CONFIG_THINGER_IOTMP_PRIORITY	7	Client thread priority
CONFIG_THINGER_IOTMP_KEEPALIVE_SECONDS	60	Keep-alive interval
CONFIG_THINGER_IOTMP_MAX_MESSAGE_SIZE	4096	Maximum message body size
CONFIG_THINGER_IOTMP_TX_QUEUE_DEPTH	8	Outbound message queue depth
CONFIG_THINGER_IOTMP_MAX_RESOURCES	16	Maximum registered resources
CONFIG_THINGER_IOTMP_TLS	y	Enable TLS (requires mbedTLS)
CONFIG_THINGER_IOTMP_RECONNECT_BASE_MS	1000	Reconnection base delay
CONFIG_THINGER_IOTMP_RECONNECT_MAX_MS	60000	Reconnection max delay

Server API

The client provides blocking, thread-safe methods callable from any thread:

// Properties
thing.set_property("config", data);
thing.get_property("config", result);

// Data buckets
thing.write_bucket("readings", data);

// Endpoints
thing.call_endpoint("email_alert");
thing.call_endpoint("webhook", payload);

Architecture

┌──────────────────┐  ┌──────────────────┐
│   Application    │  │   Sensor thread  │
└────────┬─────────┘  └────────┬─────────┘
         │ thing["res"] = ...  │ thing.stream("res")
         ▼                     ▼
┌─────────────────────────────────────────┐
│           IOTMP Client Thread           │
│  poll() + eventfd + keepalive + streams │
├─────────────────────────────────────────┤
│        IOTMP-Embedded (core)            │
│   PSON encoder/decoder + messages       │
├─────────────────────────────────────────┤
│       Zephyr BSD Sockets + mbedTLS      │
└─────────────────────────────────────────┘

Requirements

• Zephyr RTOS v4.0+
• CONFIG_NET_SOCKETS=y
• CONFIG_CPP=y and CONFIG_STD_CPP17=y
• CONFIG_GLIBCXX_LIBCPP=y (for STL support)
• CONFIG_EVENTFD=y

License

MIT License — see LICENSE for details.