rsplayer_firmware

This repository contains the firmware for the hardware controller of the rsplayer music player system. The firmware is designed to run on a Raspberry Pi Pico (RP2040 microcontroller) and serves as the main user interface and control hub for the system.

It works in conjunction with the main rsplayer application (running on a separate host, like a Raspberry Pi) and the custom hardware defined in the rsplayer_hardware project.

Features

• System Control: Communicates with the main rsplayer application via USB to send commands like Play, Pause, Next, Previous, and Power Off.
• Power Management: Controls power relays for the entire system, including the host Raspberry Pi and the main Power Supply Unit (PSU).
• User Interface:
  • Displays system status, volume levels, and input source on a 128x64 ST7920 or ILI9488 LCD.
  • Automatically dims and turns off the display backlight after a period of inactivity.
• Input Handling:
  • IR Remote: Responds to commands from a standard NEC-protocol IR remote.
  • Rotary Encoder: Allows for precise volume adjustment.
  • Rotary Encoder Button:
    • Short Press: Toggles Play/Pause.
    • Long Press (>5s): Toggles system power.
• DAC Control:
  • Directly manages an I2C-connected DAC (AK4490 and AK4497 currently).
  • DAC software volume control (serial mode).
  • Switches between DSD and PCM modes.
  • Cycles through various DAC digital filters and sound settings.
• Input Source Selection: Toggles between the internal I2S signal from the host and an external optical/coaxial input.
• Persistent Settings: Saves the last used volume and input source to the microcontroller's flash memory, restoring them on startup.

Demo

Hardware

This firmware is specifically tailored for the custom hardware designed in the rsplayer_hardware project. The key components are:

• Microcontroller: Raspberry Pi Pico (RP2040)
• Display: ST7920-based 128x64 monochrome LCD or ILI9488 based 480x320.
• DAC: An I2C-controlled Digital-to-Analog Converter.
• Inputs:
  • Standard IR receiver (e.g., TSOP38238).
  • Rotary encoder with an integrated push-button.
• Communication: USB interface for connecting to the host system.

Related Projects

• rsplayer: The core music player application that runs on a Linux host (e.g., Raspberry Pi).
• rsplayer_hardware: The repository containing the KiCad schematics and PCB layout files for the hardware.

Building and Flashing

The firmware is built using the embassy async framework for embedded Rust.

Prerequisites

1. Rust Toolchain: Install Rust using rustup.
2. Target: Add the required target for the RP2040:

   rustup target add thumbv6m-none-eabi

3. probe-rs: Install the flashing and debugging tool:

   cargo install probe-rs

4. Debug Probe: You will need a debug probe compatible with the RP2040, such as a second Raspberry Pi Pico running the Picoprobe firmware.

Building

Clone the repository and build the firmware:

git clone https://github.com/ljufa/rsplayer_firmware.git
cd rsplayer_firmware

To build for production/release:

cargo build --release --features release,ak4497,ili9488 --no-default-features

Flashing

Connect the debug probe to your development machine and the target hardware. Then, use probe-rs to flash the firmware.

To flash the release binary:

probe-rs download --chip RP2040 @/dev/shm/cargo_target/thumbv6m-none-eabi/release/rsplayer_firmware

For development:

cargo run

if it fails or stuck run ctrl-c && probe-rs info first

The command specified in the .cargo/config.toml file will be used for cargo run, which simplifies the process.