Internet Streaming Digital Node
derpeter, lukas
danimo, derchris, derpeter, lukas

Internet Streaming Digital Node

The idea is to build a “as low cost as possible” device a speaker can use to remotely present. While there would be cheaper options for some of the components we also want to use off the shelf components that are world wide available or at least interchangeable. The idea of this project was born after first test with the RPI HQ Camera which provides a great quality / price ratio. The basic features, anticipated for the first revision are:

  • Camera to record the presenter
  • HDMI Input to capture slides / audio from a PC / Laptop
  • Headset for audio recording and intercom
  • Display to show the current image
  • Touchscreen for minima user interface
  • USB Storage to record locally
  • Stream via RTMP or SRT

(for version 3.14)

  • Reconfiguration using qr-codes (e.g. using gst zbar plugin)
  • Tiny customizable / distributable firmware images
  • Integrated back-channel for audio and video
  • Using the back-channel to implement talks with multiple speakers
  • Integration into existing conference tools to allow audience participation (maybe serverside, to reduce locally required bandwidth and computing power)
  • Whiteboard and/or Pointer functionality
  • Quick-“Screen blanking / Audio muting” functionality for instant privacy
  • Allow for PDF-slides instead of using HDMI-Input (premium: store all information so it could automatically be re-rendered with the original pdf later on, for higher quality)
  • More stable and overall better case with less loose wires (especially the camera-flex…)
  • Integrating camera into a ring-light
  • Decouple camera+display to reduce camera wiggle when using the touchscreen
  • Solve power delivery issues for ring-light
  • Reduce desk-footprint
  • Better solution for audio (very cheap headsets are not the yellow from the egg)
  • Better options for wireless networking (integrated wifi on the pi4 is not-that-great and useless if bluetooth is also used)
  • Bluetooth remote for quick scene switches
  • Easier to build

(smartphone holder, smaller case / screen, different cam holder)

(final case, final screen, improvised tripod mount, final cam mount)

Camera casing

alles 30 mal !

  • Raspberry Pi 4 (4GB)
  • Raspberry Pi HQ Kamera 6mm Objektiv
  • Raspberry Pi HQ Kamera
  • Raspberry Pi USB-C Netzteil
  • Raspberry Pi microHDMI Adapter (für Fallback-Setup als reine Kamera)
  • Mini-Kühlkörper (ohne Lüfter)
  • Micso SD (SanDisk Ultra 16GB)
  • HDMI Kabel (2m)
  • Offizielles Raspberry Pi 7“ Touchscreen Dingsie
  • Komisches Plastikgehäuse für Pi+Touchscreen
  • USB HDMI Capture Nubsies
  • 3/8” auf 1/4“ adapter nubsies zum stativ-montieren des display-gehäuses
  • Stativ + Ringlicht
  • Kugelkopf für Kamera
  • 1/4” muttern (fehlkauf…)
  • USB Headset
  • Netzwerkkabel (Nehmen wir aus FrOSCon Bestand)

(copy from BOM when final)

Das ist eine Packliste an Dingen, die wir zum zusammenbauen vermutlich benötigen werden.

  • Akkuschrauber/bohrer
  • Bohrer
    • 3mm
    • 4mm
    • 6.5mm
    • 8mm
    • 9mm
  • Div. Schraubendreher
  • Heißklebedings
  • Schrauben
    • 3,5 x 10 sollten passen?
    • unklar
  • Gewindeschneider-Akkubohrer-Adaptierungsgerät
  • (todo)
  • Voctomix2 + minimal gui (TBD)
    • [✓ derpeter, 2020-07-24]finalize pulse audio branch
    • [✓ derpeter, 2020-07-16]add raspivid gstreamer source to vocomix (optional)
    • [✓ derpeter, 2020-07-16]test multiple video4linux sources / check for missing options
    • [✓ snoopy, 2020-08-01]find a way to fix green bar in encodings with omx h264 enc
    • create new recording / streaming sink so we only encode once
      • (optional) SRT instead of RTMP in streaming script
    • systemd Units
    • find out if we can have the cam loop image on the HDMI port (optional)
    • output vocotmix preview to HDMI (optional)
    • [✓ derpeter, 2020-07-24]add webapp for smartphones / tabletts to switch scene etc and maybe also config menu (Necro)
    • there is a gpio on the cam which we could use for a tally
  • mumble client headless (stb)
    • select headless mumble client
      • Binary in git repo, all configuration from command line options.
      • Sample command line: talkiepi -server -username tony_tester -channel Tech
    • read config from SD card
    • audio routing
  • raspiOS 32bit (64bit muss man mal testen ob cam und encoder tut)
    • things we want to build our self make root
    • enabel cam interface
    • set memory split to 256/512 (needs testing)
    • make root filesystem read only to prevent corruption
    • disable all services we dont need
    • disable screen blank raspi-config
    • enable gl desktop via raspiconfig
    • disable pi audio(we dont want it, it only adds devices we dont need an may eat cpu)
    • rotate screen
    • add voc packet repo - derchris
    • create image with all components we need
    • think on update strategy (ansible / infobeamer updater / ...)
    • provide images to download in case user needs to reflash
  • openvpn client (ggf 2. openvpn VM oder aber auch wireguard aufsetzen das die nciht in unserm management netz hängen)
  • ssh

Paketmaße: 30x27x20 (min. LxBxH in cm)

Raspberry Pi

  • Raspberry Pi + Touchscreen + Kamera
  • (+ USB-Stick, + HDMI-Stick mit Verlängerung)
  • Kugelkopf
  • Stativ
  • Stromkabel


  • Headset

Externer Anschluss

  • HDMI-Kabel
  • Netzwerk-Kabel


  • Ringleuchte
  • Stativ


  • HDMI-Adapter (Für den Notfall)
  • Bluetooth-Fernbedienung
  1. Helium
  2. Lithium
  3. Beryllium
  4. Boron
  5. Carbon
  6. Nitrogen
  7. Oxygen
  8. Fluorine
  9. Neon
  10. Sodium
  11. Magnesium
  12. Aluminum
  13. Silicon
  14. Phosphorus
  15. Sulfur
  16. Chlorine
  17. Argon
  18. Potassium
  19. Calcium
  20. Hydrogen
  21. Titanium
  22. Vanadium
  23. Chromium
  24. Manganese
  25. Iron
  26. Cobalt
  27. Nickel
  28. Copper
  29. Zinc
  30. Gallium
  • projects/isdn.txt
  • Last modified: 2024/05/12 17:40
  • by andi