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https://github.com/espressif/esp-idf.git
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Chen Jichang
57 lines
2.1 KiB
Markdown
57 lines
2.1 KiB
Markdown
# ESP Hardware Abstraction Layer for PCNT Peripherals
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> [!NOTE]
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> 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.
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## Overview
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The `esp_hal_pcnt` component provides a **Hardware Abstraction Layer** for PCNT (Pulse Counter) peripherals across ESP-IDF supported targets. This HAL enables efficient counting of external pulses and signals, with support for quadrature encoders, frequency measurement, and position tracking applications.
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## Architecture
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The PCNT HAL is structured in two main sub-layers:
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1. **HAL Layer (Upper)**: Defines the operational steps and data structures required to control PCNT peripherals (e.g., initialization).
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2. **Low-Level Layer (Bottom)**: Serves as a translation layer between the HAL and the register files defined in the `soc` component, handling target-specific register configurations.
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## Features
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### Core Counting Features
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- Bidirectional pulse counting (increment/decrement)
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- Configurable counting range with high/low limits
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- Counter value read operations
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- Counter clear and reset functionality
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- Start/stop control for counting operations
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### Channel Configuration
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- Edge action configuration:
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- Hold: Keep current count value
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- Increase: Increment count value
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- Decrease: Decrement count value
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- Level action configuration:
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- Keep: Maintain current count mode
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- Inverse: Invert count direction
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- Hold: Freeze count value
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### Event Detection
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- Threshold events
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- High/low limit events
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- Zero-crossing events
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- Watch-point events
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- Step events
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### Signal Processing
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- Glitch filtering with configurable filter width
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## Usage
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The HAL functions primarily serve ESP-IDF PCNT peripheral drivers such as `esp_driver_pcnt` component.
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Advanced developers can use these interfaces directly when implementing custom pulse counting applications, with the understanding that API stability is not guaranteed.
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## Dependencies
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- `soc`: Provides chip-specific register definitions and peripheral capabilities
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- `hal`: Core hardware abstraction utilities and macros
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