What is it

Louder-ESP32-Pro is a feature-packed version of the Louder-ESP32-Plus, which hosts most of the optional extras as standard, adds support for color TFT screens, and, perhaps most importantly, adds an industrial-grade heat release solution for reliable heavy-duty operation.

It comes in Raspberry Pi 5 shape with the most important component placed to follow the original heat release pattern. This allows the use of Raspberry Pi aluminum radiators, including those with soft-controlled fan connectors, that can be driven through Louder-ESP32-Pro software when operating in hot conditions.

Louder-ESP32-Pro is equipped with a high-quality TAS5825M DAC with powerful DSP features, allowing audio tuning to turn your speakers into high-quality audio streamers, big or small likewise. Onboard ESP32-S3 with 8MB PSRAM is there to ensure enough horsepower for solid streaming capabilities.

It is designed to be used with USB-PD-enabled power sources, so powering it is as easy as plugging in a standard laptop power charger. For maximum power, a 65W power source is recommended, but it would also happily accept quick-charge phone power adapters, and even standard USB-C power adapters, with limited output power

• TAS5825M DAC with integrated DSP
• Digital volume control (avoids loss of resolution compared to software volume)
• Gain digital control
• Parametric EQ (15xBQ), 128-tap FIR, 3-band DRC, AGL
• Supports both BTL (stereo) and PBTL (mono) modes

Use cases

The main use case for the Louder-ESP32-Pro is Home Assistant and Music Assistant integration via ESPHome, although it is there to fit your own needs and implement your ideas.

• Multi-Room Audio with Snapclient (Beta) Use Louder-ESP32-Pro as a Snapclient endpoint to create perfectly synchronized multi-room audio systems. Ideal for distributed music playback without proprietary lock-in.
• Standalone Player with Squeezelite-ESP32 (Beta) Run Squeezelite-ESP32 for a self-contained network audio player supporting Spotify Connect, AirPlay, and Logitech Media Server (LMS) — no external computer required.
• Educational Projects & Teaching Platforms
  A powerful tool for schools, universities, and technical education. Louder-ESP32 can be used to teach embedded systems, digital audio, networking, and open-source software — ranging from simple audio playback labs to advanced DSP, streaming, and real-time systems projects.
• Research, Prototyping & Experimentation
  Well-suited for rapid prototyping of audio devices, proofs-of-concept, and research projects involving DSP, low-latency streaming, wireless audio, or human-machine interaction.
• A Foundation for Custom Products & DIY Builds
  With all firmware and tooling fully open source, Louder-ESP32 is an ideal base for custom audio devices — whether you’re building a personal DIY project, a small production run, or a community-driven product.

Features

⚠️ ** Squeezelite-ESP32 support for the ESP32-S3 is an experimental feature and is not fully stable; for styable operation, 'classic' ESP32 is recommended. Please refer to the original repo for up-to-date support information

⚠️ *** Snapclient support for the ESP32-S3 is in beta and not fully stable as well. For best results, 'classic' ESP32 is recommended.

⚠️ Louder boards will connect to passive speakers; you can't use headphones or an external amp

💡 Need to connect an external amp? Check out HiFi-ESP32 / HiFi-ESP32-Plus and Amped-ESP32 / Amped-ESP32-Plus

💡 Don't need DSP capabilities? Check out Loud-ESP32 / Loud-ESP32-Plus

💡 Looking for a more feature-packed version? Check out Louder Esparagus and Esapragus Audio Brick

Onboard PSRAM

Audio streaming requires proper buffering to work, even with the ESP32's 500K of RAM; it is a challenging task. For that reason, all Louder-ESP32 board versions have an 8 MB PSRAM chip onboard, connected via a high-speed interface.

Board Pinout

DAC interface

Ethernet

Fan (optional)

Louder-ESP32-Pro have a 4-pin fan connector, with a size and pinout borrowed from the Raspberry Pi 5 specification. It can be used to connect a 5V fan, which can be controlled by the onboard ESP32-S3. The fan speed can be set in software, and the actual speed can be read back from the fan's tachometer output.

Peripheral

Built-in Mic

Louder-ESP32-Pro boards have a built-in I2S microphone hooked up to the left channel. It is connected to a dedicated I2S bus, and can be used for wake word functionality in the Home Assistant or for custom firmware.

Software Options

• Home Assistant smart home audio and notifications. Start from the web-installer, as soon as you configure WiFi, the boards will be discovered by the ESPHome add-in automatically. Dedicated configs can be found in the documentation for simple and stable media-player, experimental sendspin protocol, and experimental snapclient component
• Squeezelite-ESP32 Spotify Connect, AirPlay, Bluetooth or Logitech Media Server. Flash directly from your browser using the web-installer. Configure WiFi using Hotspot (default password: squeezelite). Don't forget to exit Recovery mode when done.
• Snapclient multi-room audio streaming with snapserver. Flash directly from your browser using the web-installer, as soon as you configure the WiFi board will discover the snapserver automatically
• Snapclient (edge) - developer version. Developer's version of the snapclient, less stable and more feature-rich for those who cannot wait for new features to be released. Installed via web-installer, similar to standard snapclient
• Apple AirPlay 2 with multi-room sync. Use Platformio IDE to build and flash the AirPlay2 firmware. Pre-configured configurations and web-installer is a work in progress, but you can get it working by providing board configurations and building firmware yourself.
• Your own software. Use Arduino IDE or Platformio IDE and the provided software samples

⚠️ Both squeezelite-esp32 and snapclient are in beta and not fully stable on the ESP32-S3. The main use case for the Louder-ESP32-Pro is Home Assistant and Music Assistant integration via ESPHome, although it is there to fit your own needs and implement your ideas.

Using with Home Assistant

Both Louder-ESP32-mini versions were created specifically to be used with Home Assistant via ESPHome integration. For both boards, rich configs were pre-created with hardware configuration for common use cases. These include

• media_player component for simple and robust media playback and TTS announcements (with ducking effect)
• Sendspin media player – new experimental protocol for multi-room sync with media controls and more
• An experimental snapclient component that allows near-perfect multi-room sync and seamless integration with Music Assistant
• Another snapclient fork with an implemented 15-band software equalizer and a rich set of EQ presets

Configurations are being actively maintained and upgraded, new experimental components added for you to test and enjoy

Flashing ESP32-S3

ESP32-S3 boards have two ways of firmware update: (1) similarly to classic ESP32, they can be flashed over built-in UART, or (2) uniquely for S3, over built-in USB host controller. Since it is firmware-controlled, it may be disabled if not used (or, more commonly, not available with factory default empty firmware). When come unflashed ESP32-S3 device comes into a boot loop, with a USB-CDC device appearing and disappearing every second, and requires a special flashing initialisation sequence to get flashed:

• Press the IO0 (FLASH) button and keep it pressed
• Press and release the RESET button. Release the FLASH button.
• ESP32-S3 will enter download mode, and the USB-CDC device will appear and stay available
• Run flashing routine as usual, either through web-serial or esp_tool
• This time, it is not possible to reboot the device over USB, so press RESET once more
• Device will boot normally into firmware, and if USB-CDC is enabled in the firmware, you will be able to flash it normally, download mode and reset sequence will work over USB.
• If you manage to flash firmware without USB-CDC support, you need to go through the above sequence once more

Hardware

Please visit the hardware section for board schematics and PCB designs. Note that PCBs are shared as multi-layer PDFs.

BTL and PBTL mode (TAS5825M DAC)

TAS5825M DAC Allows 2 modes of operation - BTL (stereo) and PBTL (parallel, or mono). In Mono amp will use a completely different modulation scheme and basically will fully synchronize output drivers. Since Louder-ESP32-mini has only a single output, it is mandatory to use PBTL mode, which is done by setting a few registers in the DAC. The default configuration is BTL, so you need to change it to PBTL for proper operation. This is done in the configuration, and the configuration is stored in the dac_controlset variable in case of squeezelite-esp32: dac_controlset: {"init":[{"reg":3,"val":2},{"reg":3,"val":3},{"reg":2,"val":4}],"poweron":[{"reg":3,"val":3}],"poweroff":[{"reg":3,"val":0}]}

Important point, this will send only one channel to the output, that’s just how the DAC works. True mono as (L+R)/2 is possible via more in-depth configuration that is possible with ESPHome and snapclient, but not with squeezelite-esp32. If you want to use squeezelite-esp32, you need to make sure your source is mono, or you will get only one channel of audio.

TAS5825M DSP capabilities

The TAS5825M DAC has a very powerful DSP, that allows doing lots of data processing on the silicon, that otherwise would take a considerable part of your CPU time. As of the moment of writing it is mostly an undiscovered part of the DAC, since unfortunately, TI is not making it very easy for developers. (A minute of complaint) To be more specific, you need to be (A) a proven hardware manufacturer to get access to the configuration software, namely PurePath. (B) you need to apply for a personal license and go through an approval process, and after a few weeks of waiting you get access to one DAC configuration you asked for. (C) You find out that it will work with TI's own evaluation board that will set you back $250 if you'd be able to find one. Otherwise, all you have is a list of I2C commands that you need to transfer to the device on your own cost. No wonder no one knows how to use it.

But moanings aside, what do you get after:

• Flexible input mixer with gain corrections
• 15 EQ with numerous filter configurations
• 3-band Dynamic Range Compression with flexible curve configuration
• 128-tap FIR filter
• Automatic Gain Limiter with flexible configuration
• Soft clipper
• and a few other things

At this moment I'm adding most useful features one by one, focusing on EQ and Bi-amp filtering capabilities. All of the above are available right now for experimentation. I'm keen to hear your feedback while I'm moving forward with porting this to other software options

• [X] - Bare I2S TAS5805M library
• [X] - espragus-snapclient software with self-hosted UI
• [X] - ESPHome component with on-the-fly configuration changes
• [ ] - squeezelite-esp32

Louder-ESP32 Pro case

Louder-ESP32-Pro boards are mechanically compatible with aluminum cases for Raspberry Pi 5. The most important components that release heat under heavy operation would be covered by the case heat release pads. On top of that, the board allows connecting a 4-pin fan with speed control and RPM readout, so it can be engaged only when needed.

Restocking & Availability

New restock batches are regularly ordered from the factory, and I plan to keep all versions available at least until the next board revision is released. For current availability, you can also check the official reseller Elecrow.

USA shipping Update

Due to the new tariffs introduced by the Trump administration, standard shipments are temporarily on hold. However, shipping to the US has now resumed via UPS, though rates are currently quite high. I’ll fully resume regular shipping as soon as the restrictions are lifted. In the meantime, you may consider ordering through Elecrow.

Sponsorship & Community Support

If you’re working on an open-source project, an educational initiative, or any pro-bono/volunteer effort, feel free to reach out for sponsorship details. I’ll do my best to provide discounts or even free boards.

Custom Design & Consultation

If you’re interested in a custom design based on or inspired by my boards, I also offer contract design work and consultation when needed.

Most orders are shipped the next business day morning. All shipments are tracked. Delivery time in the EU is 3-7 days, outside 2-3 weeks, depending on the distance. After 30 days, the package is considered lost - reach out for a refund or replacement.