Using Embassy

Embassy is an async framework for embedded Rust. It provides efficient task scheduling and hardware abstractions, making it a good fit for low-power, responsive firmware.

Embassy Book

Embassy GitHub

Key features

• Async programming model with async/await
• Lightweight executor suitable for resource-constrained devices
• Works with multiple HAL ecosystems for portability
• Common peripherals supported (timers, DMA, interrupts)

Use cases

1. Low-power devices: reduce idle CPU usage with async tasks
2. Concurrent workloads: run sensors, comms, and UI together
3. Real-time embedded systems

Montic support matrix

	W02	W04
Chip	Expressif ESP32-C6	WCH CH32V208
Status	✔ Support	✔ Support

Prerequisites

Windows

1. Install Rust

   Install Rust via rustup and make sure cargo is available.

2. Install common tools

   cargo install cargo-generate
   cargo install probe-rs-tools

3. Install ESP32-C6 flashing tool (for W02)

   cargo install espflash

Linux

1. Install Rust

   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

2. Install common tools

   cargo install cargo-generate
   cargo install probe-rs-tools

3. Install ESP32-C6 flashing tool (for W02)

   cargo install espflash

macOS

1. Install Rust

   brew install rustup
   rustup-init

2. Install common tools

   cargo install cargo-generate
   cargo install probe-rs-tools

3. Install ESP32-C6 flashing tool (for W02)

   cargo install espflash

Montic W02 (ESP32-C6) quick start

Montic W02 uses ESP32-C6. We recommend using Embassy with Espressif’s Rust ecosystem (esp-hal).

1. Add the target

   rustup target add riscv32imac-unknown-none-elf

2. Get a template or example

   You can generate a template with cargo generate, or start from the Embassy examples in esp-hal:

   cargo generate --git https://github.com/esp-rs/esp-hal --name montic-w02

   Tip

   The esp-hal repository includes Embassy examples and board configuration hints. Check the README or docs for ESP32-C6 pin and clock settings.

3. Build and flash

   cargo build --release
   espflash flash --monitor target/riscv32imac-unknown-none-elf/release/montic-w02 --chip esp32c6

   Note

   Replace the binary name with your project name if it differs.

Montic W04 (CH32V208) quick start

Montic W04 uses CH32V208. We recommend the community CH32-RS HAL with Embassy for async development.

1. Add the target

   rustup target add riscv32imac-unknown-none-elf

2. Create a project and add the HAL

   Create a project with cargo new, then add the CH32-RS HAL and Embassy dependencies in Cargo.toml. See the CH32-RS examples for reference.

3. Build and flash

   Build with cargo build --release, then flash using the WCH-Link or USB ISP tools.

   Tip

   For W04 flashing steps, see the W04 getting started guide.

Embassy app structure example

Below is a minimal Embassy app skeleton. Replace the GPIO and timer setup with the appropriate HAL for your board.

#![no_std]
#![no_main]

use embassy_executor::Spawner;
use embassy_time::{Duration, Timer};

#[embassy_executor::main]
async fn main(_spawner: Spawner) {
    // TODO: initialize your HAL peripherals (e.g., GPIO)
    loop {
        // TODO: toggle LED
        Timer::after(Duration::from_millis(500)).await;
    }
}

Tip

For the onboard LED pin, see the W02 or W04 product page for the GPIO mapping.

More resources

Embassy Book Core concepts and official examples

Embassy GitHub Source code and sample projects

CH32-RS Community Rust HAL support for WCH chips