Note

This component is currently in beta. Its API, behavior, and compatibility may change at any time and without notice; backward compatibility is not guaranteed. Use caution when integrating into production systems.

Overview

The esp_hal_rmt component provides a Hardware Abstraction Layer for the RMT (Remote Control Transceiver) peripherals across all ESP-IDF supported targets. It serves as a foundation for the higher-level RMT drivers, offering a consistent interface to interact with RMT hardware while hiding the complexities of chip-specific implementations.

Architecture

The HAL architecture consists of two primary layers:

HAL Layer (Upper): Defines the operational sequences and data structures required to interact with RMT peripherals, including:
- Initialization and de-initialization
- TX/RX channel control operations
- Memory and DMA management
- Carrier and modulation configuration
Low-Level Layer (Bottom): Acts as a translation layer between the HAL and the register definitions in the soc component, handling:
- Register access abstractions
- Chip-specific register configurations
- Hardware feature compatibility

Features

Unified RMT interface across all ESP chip families
Support for both transmit and receive channels
Flexible pulse timing and encoding capabilities
Carrier wave modulation for IR remote control
Loop transmission mode for repeated patterns
DMA support on capable chips for large data transfers
Multiple clock source options
Memory block allocation and management

Usage

This component is primarily used by ESP-IDF peripheral drivers such as esp_driver_rmt.

For advanced developers implementing custom RMT solutions, the HAL functions can be used directly. However, please note that the interfaces provided by this component are internal to ESP-IDF and are subject to change.

Dependencies

soc: Provides chip-specific register definitions
hal: Core hardware abstraction utilities and macros