Topic: Reality check on using CHB for multiple photobooth-type application

Hi everyone -

I have a photobooth application in mind, and wanted to get a reality check that it's sensible (and possible) to implement it using CHB. I'm learning about CHB and eager to hack at it but want to make sure I'm barking up the right tree, so to speak.

Here's the general requirements:
-- Imagine 8 tables, each with a button, webcam, speaker, and overhead light hanging from a high ceiling above
-- You sit at a table, press the button, you get a confirmation sound (click, or whatever) from the speaker, the light goes on, and the webcam snaps a picture
-- The picture is now available on a central server somewhere
-- One note is that for effect I need the light not just to switch on and off, but to fade on and off quickly but smoothly as if turned by a dimmer switch; also the light needs to be bright like a standard incandescent lightbulb

Here's what I'm thinking as the overall architecture
-- Eight CHBs, one for each table, plus one mounted on the ceiling to control all 8 lights
-- All CHBs have TP-Link USB Wifi adaptors 
-- All CHBs powered by by AC plugs
-- Each table CHB is connected to a standard inexpensive USB webcam using standard Unix/Linux drivers, with the camera mounted at the side of the table; to a standard cheap speaker via audio out; and to a standard cheap Arduino-style button
-- The table CHBs are programmed to watch the button; when it's pressed, they play a sound (e.g. a photo click sound, to give the users immediate feedback) on the speaker, capture the image from the webcam, and upload the image to the server; they also meanwhile tell the ceiling USB to turn on and off the light above that particular table (via node.js or similar approach)
-- The ceiling CHB is connected to two 4-channel DMX dimmer packs (to save money versus one 8-channel pack), into which the overhead lights are plugged
-- The ceiling CHB waits for instructions via Wifi (via node.js or similar approach) to turn on or off any of the 8 lights and does so by controlling the DMX dimmers with the necessary signals

-- Is this nuts -- or am I on the right path?
-- Is this overkill? Is there an obvious way to do it more simply and/or less expensively?
-- Can I use one CHB to control the cameras and speakers at multiple tables (using USB port hubs to get more than 3 USB devices connected)
-- Any obvious gotchas or especially tricky issues to watch out for?

THANKS for any help or tips you can offer!


Re: Reality check on using CHB for multiple photobooth-type application

Sounds like fun.  Some random comments:

  • I use a CHB in an embedded role where wifi used for admin only.  Wifi becomes unresponsive after a while.  I have not investigated yet, and there is one other post in this forum reporting a similar issue.

  • Given the relatively low cost of the hardware against labor and the cost of failure, I think using one CHB per table seems very sane.  You may be able to get by with fewer, but this plan gives you predictable response time when multiple tables are in use simultaneously.

  • I have never tried using USB webcams, but I think Maddox has demonstrated this.

While I do love the CHB's, you might also consider the beagle bone and (when they ship) raspberry pi as platforms.