Crate mqtt_async_embedded 

Async MQTT Client for Embedded Systems

mqtt-async-embedded is a no_std compatible, asynchronous MQTT client designed for embedded systems, built upon the Embassy async ecosystem.

Core Features

• no_std & no_alloc: Designed to run on bare-metal microcontrollers without requiring a standard library or dynamic memory allocation. Buffers are managed using heapless.
• Fully Async: Built with async/await and leverages the Embassy ecosystem for timers and networking, ensuring non-blocking operations.
• Rust 2024 Edition: Uses native async fn in traits, removing the need for async-trait.
• MQTT v3.1.1 and v5 Support: Supports both major versions of the MQTT protocol, selectable via feature flags.
• Transport Agnostic: A flexible MqttTransport trait allows the client to run over any reliable, ordered, stream-based communication channel, including TCP, UART, or SPI.
• QoS 0 & 1: Implements “at most once” and “at least once” delivery guarantees.

Usage

To use the client, you need to provide a transport implementation, configure the client options, and then run the poll method continuously to handle keep-alives and incoming messages.

let transport = MyTransport;
let options = MqttOptions::new("my-device-id", "mqtt.broker.com", 1883);
let mut client = MqttClient::<_, 5, 256>::new(transport, options);

client.connect().await?;
client.publish("sensors/temperature", b"25.3", QoS::AtLeastOnce).await?;

loop {
    // Poll the client to process incoming messages and send keep-alives.
    if let Some(event) = client.poll().await? {
        // Handle incoming publish packets, ACKs, etc.
        println!("Received event: {:?}", event);
    }
}

Re-exports

pub use client::MqttClient;

pub use client::MqttOptions;

pub use packet::QoS;

Modules

client

The Asynchronous MQTT Client

error

Error Types

packet

MQTT Packet Structures and Serialization

transport

MQTT Transport Abstraction

util

MQTT Serialization Utilities