ESP-IDF Extra Components

The Espressif Serial Slave Link (ESSL) library is designed for use on a HOST device to facilitate communication with ESP chips acting as SLAVE devices. It supports two primary communication modes:

1. SDIO
2. SPI slave HD mode

The esp_encrypted_img component provides an API to decrypt data formatted as an "ESP Encrypted Image". This format is designed for integrating pre-encrypted firmware into Over-the-Air (OTA) updates or for securing custom data payloads.

The component supports two primary cryptographic schemes:

1. RSA-3072: Uses an RSA-3072 public key to encrypt an AES-GCM key.
2. ECIES-P256: Uses Elliptic Curve Integrated Encryption Scheme (P-256 curve) to derive a shared secret via ECDH, which is then used to derive an AES-GCM key via HKDF.

The esp_cli component provides a Runtime Evaluation Loop (REPL) mechanism for ESP-IDF-based applications. It enables the creation of interactive command-line interfaces (CLI) that support user-defined commands, command history management, and customizable callbacks for execution.

It relies on two other components:

• esp_linenoise: Handles line editing and input.
• esp_cli_commands: Handles command parsing and execution.

Key features include modular REPL management (start/stop control), thread-safe operation via FreeRTOS semaphores, and optional command history persistence to a filesystem.

esp_linenoise is a multi-instance line editing library adapted from the original linenoise for the Espressif IDF ecosystem. Unlike standard line editors, it supports multiple independent instances, allowing an application to manage multiple input contexts simultaneously, such as different UART consoles, shells, or network sessions.

Key features include:

• Independent instances: Each instance has its own configuration.
• Per-instance configuration: Customize history, prompts, and line-editing behavior for each instance.
• Callbacks: Support for custom completion and hint callbacks.
• IDF Integration: Uses IDF-style memory and error handling.

The esp_lcd_qemu_rgb component provides an interface for the virtual RGB panel available in Espressif's QEMU fork (version 8.1.3-20231206 and later).

This virtual panel is designed for displaying graphical interfaces in a simulated environment. Unlike real hardware, this virtual panel includes a dedicated frame buffer that is independent of the internal RAM, allowing user programs to populate pixels directly into it.

The network_provisioning component provides APIs to control a network provisioning service. This service allows an external device to receive and configure network credentials on an ESP32 device via secure Protocol Communication (Protocomm) sessions.

Supported provisioning methods include:

• Wi-Fi: Provision credentials using either SoftAP or Bluetooth LE.
• Thread: Provision credentials using Bluetooth LE.

The Touch Element Library is a collection of common UI elements designed for touch-based applications. It provides high-level abstractions for touch interactions, allowing you to implement interfaces quickly using elements like button, slider, and matrix.

Key features include:

• Supported Elements: button, slider, and matrix.
• Event Support: Handles touch events such as Press, Release, and Long Press.
• Notification Mechanisms: You can handle events by either registering an event callback or by subscribing to events within a task.