This document provides an overview of a digital jukebox project. It introduces the speaker and their background in audio and software development. It then details the various components of the digital jukebox system, including using Subsonic for media management, Docker containers to run services, Kafka for messaging, software-defined radio for randomness, and IoT devices like the Oracle CodeCard and Particle Photon for physical interaction. Finally, it provides a demo and discusses future enhancements and includes reference links.

1. (Everything But The Kitchen Sink)
Digital Jukebox
DEVOXXUK 2019

2. …so what are we talking about…
 Introductions
 My Life In Audio
 RadioNonsense.com
 Digital Jukebox
 Demo
 Q&A
 Reference Links

3. Who Am I?
• Architect @ Dell Technologies since 2011
• From St. Paul, MN
• Longtime Software Engineer/Architect
• Business and Software Shops
• Individual Contributor and Leadership Roles
• All phases from project conception to implementation
• Sideline projects at home
• Music Lover
• 10+ years online radio station of personal music
• Contact Info
• Email: scott [dot] sosna [@] buddhadata [dot] com
• LinkedIn: https://www.linkedin.com/in/scott-sosna

4. My Audio History

5. My Audio History: Analog

6. My Audio History: Analog

7. My Audio History: Analog

8. My Music Technology: Analog

9. My Audio History: Analog

10. My Audio History: Digital

11. My Audio History: Digital

12. My Audio History: Digital

13. My Audio History: Digital

14. Radio Disc Jockey

15. RadioNonsense

16. RadioNonsense.com
 Tired of selecting CDs to bring into work
 Large personal music collection
 Some CDs not good for software development
 Worked for NetRadio.com
 One of first online music sites
 Figured it was pretty easy, let’s do it myself
 Ran for over 10 years
 Allowed anyone to listen
 Got listeners all over the world

17. RadioNonsense Technology

18. Digital Jukebox

19. Jukebox Components
 Infrastructure
 Subsonic
 Docker
 Kafka
 Software-Defined Radio
 IoT Devices

20. Infrastructure Requirements
 Raspberry Pi Model 3
 CPU: 1.2 GHZ quad-core ARM
 Memory: 1GB SDRAM
 Network: wired, wi-fi, Bluetooth
 GPU: Broadcom VideoCoreIV @ 400Mhz
 Operating System
 Raspian Stretch
 Recommend Lite (no desktop)

21. Infrastructure Requirements
 Router
 Wi-Fi for Rpi’s to connect to
 DHCP address reservation
 Separate from home network

22. Infrastructure Requirements
 Anker PowerPort 6
 A Raspberry Pi 3 requires 2.5A
 Sufficient Power Important
 Many adapters don’t provide enough
 RPi will run slow or crash
 Definitely see console logging

23. Digital Jukebox Technical Layout

24. Digital Jukebox
Components

25. Subsonic

26. Subsonic
 Web-based Media Management
 Manage music collection
 Stories of multiple TBs of songs
 Play or stream music collection
 mp3, ogg, flac, wav, wma, more
 also internet radio, podcast, video
 Integrates with Android/IOS apps
 Requires premium version
 Airsonic: license-free alternative
 RPi install instructions in project
 subsonic-client/src/main/resources/notes.txt
 RESTful API for app development
 Retrofit Interfaces for each services
 16 services
 All parameters are query parameters
 Generated response objects from XSD

27. Using Subsonic API
Creating Service
Making Call

28. Docker
 Easy to install on Raspberry Pi
 Five Containers
 Scheduler: queue random songs to playlist
when under threshhold
 Now Playing: publish song changes
 Subsonic doesn’t have callbacks
 Twitter: publish event info to Twitter
 Code Card: calls for IoT device
 Particle: calls and event handling
 2-way interaction with IoT device
 Problems
 FROM image must be ARM-compatible
 hypriot/rpi-java
 Commands during image build
 Jukebox images built on i686 Fedora
 not building on Raspberry Pi
 No Image Repository
 Export, Copy, Import
 SSL Certificates
 Image comes with none
 Manually copied keystore
 Map volume in Docker container

29. Docker

30. …and the rest...
Kafka
 Publish/Subscribe messaging
 Runs on bare metal
 Difficult to find ARM instance
 Docker-compose not available
 Really slow in Docker
 Single-instance cluster
 No robustness, more dev-like
 Publish jukebox events to Kafka
 Multiple services consume
Random Number Generator
 RTL2832U SDR dongle for randomness
 rtl_fm turns radio broadcast into bytes
 data pipe to *nix fifo file
 service reads data into circular buffer
 generator uses buffer for raw data
 More random than standard Java
 Data based on current broadcast
 Easy to change stations as needed
 Runs on bare metal
 Fifo files not available within Docker

31. Digital Jukebox
IoT Devices

32. Oracle CodeCard

33. Oracle CodeCard
 ESP8266 Microcontroller
 80/160Mhz
 32 KiB instructions/ 80KiB user data
 TCP/IP Stack
 Wi/Fi
 Display
 Buttons
 USB Port
 16 GPIO Pins
 General –purpose input/output
 Left Button
 Short Press: Start/Stop Jukebox
 Long Press: Mute/Unmute
 Right Button
 Short Press: Next Song
 Long Press: Restart Song

34. Particle Photon IoT Platform

35. Particle Photon IoT Platform
 Cloud-based Management
 Registration and Setup
 Device monitoring
 Over-the-air firmware upgrades
 Web-based IDE
 Event logs and diagnostics
 Webhook Integrations
 Hardware
 Arduino-based microcontroller
 1MB Flash/128K RAM
 Wi-Fi and Cellular Communications
 Programmable RGB LED
 USB-powered
 GPIO, digital/analog, other functions

36. Particle Photon IoT Platform
 Software
 FreeRTOS (real-time operating system)
 Web and Desktop IDE
 C/C++ based coding
 Web IDE loads program over-the-air
 API for on-board hardware
 Particle-specific extensions
 API for communicating via cloud
 Cloud Communications
 Register functions for RESTful calls
 Subscribe Particle Cloud events
 Publish events to Particle Cloud
 Trigger webhooks to call external resources
 No local communications
 Everything goes through cloud

38. Digital Jukebox Technical Layout

39. Demo

40. Future Enhancements
 Java11 or 12
 Private Blockchain
 Subsonic API Calls to Control Streaming
 Better Logging

41. Q&A

42. Personal Links
 Email: scott [dot] sosna [@] buddhadata [dot] com
 LinkedIn: https://www.linkedin.com/in/scott-sosna
 GitHub: https://github.com/scsosna99/
 Slideshare: https://www.slideshare.net/ScottSosna
 Twitter: https://twitter.com/scott_sosna

43. Links and References
 Raspberry Pi
 Raspberry Pi Organization
 Raspbian Download Image
 Anker PowerPort 6
 The Pi Hut or Adafruit
 Subsonic
 Subsonic Home Page
 Subsonic API
 Airsonic Home Page
 Docker
 Install Docker on Rpi
 hypriot/rpi-java
 Spring Boot
 Kafka
 Kafka Home
 Kafka/Zookeeper on Rpi
 Kafka/Zookeeper on Docker/ARM
 Software-Defined Radio
 RTL2832U Software-Defined Radio
 Rtl-sdr Software
 Oracle Code Card
 CodeCard Home Page
 CodeCard Source
 CodeCard: Making an IoT Badge
 ESP8266 Microcontroller

44. Links and References
 Particle IoT Platform
 Particle Home
 Web IDE
 Console
 Device API
 Store and Amazon
 Arduino
 Home
 Reference
 RadioNonsense.com
 Shoutcast
 Icecast
 Real Audio
 Stream Guys

45. Thanks!