These events had audience voting in the form of sound. I remembered when I was a kid, on TV they would often put a camera on a VU (Volume Unit) meter to show just how loud the audience was.
I think they quit doing that for a number of reasons:
|"VU Meter" by Iain Fergusson|
- Most of the time, the meter just pegged so no difference was detected
- Big hassle for the sound guy to set up another microphone and mixer send
- People closer to the microphone would have a bigger "vote"
- Black needle on a white face not very telegenic
- As we moved to digital technologies, an analog VU meter looked old-fashioned
But some sort of SPL (Sound Pressure Level) meter would still be handy for these events.
I've also been looking for a project to learn more about Arduino.
So I sketched out the initial design for The Conference Panel.
If the project works, it would be used at these conferences to simplify some of the show mechanics.
- Big and bright enough to be seen by the audience in a hotel conference room
- Small enough to sit on a panel discussion table or hang from a lectern
- Light enough to hang from a booth wall if needed
- Durable and shippable
- Single power cord (and optionally battery powered)
- Based on regular Arduino Uno
VU Meter Features
- Built-in microphone
- Fast VU meter display
- Self-calibrating SPL meter
Game Show Features
- Buzz In mode with lockout
- Answer clock
- Simple show host controls
- Sound effects
- Wheel of fortune spinner and other random generators
- Beer resistant
- Music-synched light display
- Webcam light panel with color temperature control
- Deco lamp mode
I'm treating this like a software project. I want to create a Minimal Viable Product at each stage and iterate over the design.
Physically, I think the final project will be built on a gatorboard back and interior panel with a plexiglass front and a corrugated plastic perimeter. There will be a base where a "ribbon board" display could eventually be attached to the front and which would serve as storage for the cables and buttons.
There are a number of unknown factors that need to be defined for this project to work:
- Can an Arduino drive enough LEDs fast enough to create a clear display?
- How hard will it be to code?
- Given the presumably fast sampling rate, can we slow or average the values into something can be meaningfully displayed?
- What material should be used for the front face?
- Is an Arduino fast enough to sample the audio and drive the display at the same time?
- Get some addressable lights
- Lay them out in a radial fashion
- Write some code to display a VU-style meter.
Phase 1 Goals
- Learn the basics of Arduino programming
- See if addressable RBG LEDs are fast enough to perform the task.
I picked up a strand of Adafruit's Diffused Flat Digital RGB LED Pixels. There are 25 bright "pixels" per strand which are individually addressable via a simple serial protocol.
Then I created a layout that would place the 25 pixels on a big "dial" without cutting the strand.
The blue "pixels" aren't used in the display. But by leaving them connected, I don't need to cut and solder my strand.
To test this layout in the real world, I just eyeballed the layout and taped the strand to a box.
So far, so good!
In Part 2, I'll work on the mechanics of the light and try techniques for creating a clearer display.