SoundBoard

A simple PCB with two audio drivers, a SD card reader and a ESP32 microcontroller to play sounds via MQTT.

Features

• On factory settings or no known WiFi SSID is found, device starts in AP mode
  • To stay in AP mode, leave the SSID and password empty
• The LED show the status of the device
  • Orange: Booting
  • Blue: Connecting to WiFi
  • Green: Connected to existing WiFi
  • Violet: Started WiFi AP
  • Red: No connection to WiFi
  • White: Web or MQTT activity
• The device can be controlled via MQTT:
  • Subscripte to <prefix>/status to get the status of the device
  • Publish to <prefix>/cmd to play a sound
    • {"play": "filename.mp3", "volume": 50, "balance": 0} (volume and balance are optional)
    • {"tts": "Hello World", "lang": "de"}

Getting Started

• Default WiFi SSID: SoundBoard
• Default WiFi Password: 12345678x!

Hardware

Case

• The case could be found on Printables.

PCB

• The PCB was designed with KiCad and could be found in the pcb directory.

Development

Frontend development

• Start the frontend development server with python .\webserver.py in the html directory.
• Open the browser at http://localhost:8000/ to see the frontend.
• Set manual a cookie with overwrite-host to the hostname or ip of the device and reload the page.

ToDos/Improvement Ideas

• Add a priority flag to the MQTT messages. Stop the current playback only if the priority is higher than the current one.
• Sync volume and balance fader across all clients
• Enable/Disable Playback/Stop buttons based on the current state
• Add addidtional MQTT topics with hostname for status und command
• Refactor Code in more separat files
• Maybe: Option to queue playbacks
• Send file list in multiple messages
• If we had valid settings, but in fallback AP mode, try to connect to the last known wifi periodically
• Download audiofiles from the webinterface
• Replace play/delete/download with icons?
• Add tailing slash to the topic prefix
• Save authentication in cookie/webstore
• Add credentials to post requests
• Improve MQTT reconnection and resubscription
• Improve MQTT reconnection after boot when no connection is available
• Make MQTT status topic more "chatty"

Links

• ESP32 Based Internet Radio using MAX98357A I2S Amplifier Board
• I2S Sound Tutorial for ESP32 - DIYI0T
• schreibfaul1/ESP32-audioI2S: Play mp3 files from SD via I2S
• ESP32 Pinout Reference: Which GPIO pins should you use? | Random Nerd Tutorials
• ESP32 partition calculator: Easily Calculate ESP32 Memory and Partition Sizes