Rack KITT

Latest revision as of 09:36, 9 February 2021

A rack mounted LED array of wikipedia:blinkenlights, 1RU, which emulates wikipedia:KITTs scanner by visual, but is similar to the wikipedia:BeBox's blinkenlights for function.

[edit] What can it display?

• Status monitors
  • KITT Scanner for system load indicator
  • Fill bars for memory/cpu/disk/whatever
• Error displays
  • Guru Meditation error
  • BSOD
  • Full bright
  • red X
  • scrolling words
• Screensavers (may require multiple in sync)
  • Conways game of life
  • Matrix
  • PONG
  • Tetris
  • Flames
  • ripples
• other visuals
  • snow crash randomness (error?)
  • heartbeat (status)

A rack unit is 1.75inch high, or 44.45mm, and a 19" rack is 482.6mm wide. If we use 3mm LEDs. then we can get 9 high (means we can have a border and a 3x5 font inside), or 8 high (easier to calculate the electronics?!) and still leave room for potential airflow. (5mm LEDs could fit 8 high, but no airflow)

So at a density of 5.4575mm per LED:

• x8 high = 43.66mm - which is the recommended 0.79mm short of a RU to ensure devices can stack comfortably), then 80
• x80 width = 436.6mm = 46mm to the sides for controls/UI

Alternatively, a 16x2 LCD to display extra status/etc, would require perhaps 80mm width, so dropping the possible width of the LEDs down to around 70. (70x8 LEDs is 560 still!)

[edit] Extending the basic idea

The basic display should be standalone, but racks tend to be in servers, stacked... so there should be a way to synchronise multiple rKITTs for easier overall displays. For eg:

• KITT scanner is at the left at the start of every minute, so ALL displays sync up, and it's easier to see which is fastest...
  • say: scanner scans (a full left-right-left cycle) at X scans per 10 seconds, and only updates the speed every 10th second. That way every 10 seconds it is back to the left. 5 scans/10seconds = default. Integer scan count/10 seconds.
• most screensavers (esp Matrix) will improve across multiple lines, so a basic protocol to transmit data "down" and "up" (left/right too? probably not for this iteration)

[edit] limitations

• how many LEDs can be lit at once as powered by USB?
  • http://forums.bit-tech.net/showthread.php?p=327983 - so, maybe 20? :/ Also, ensure USB driver is correct!
  • Discussions with Brett at LCA2011 suggested closer to 80 or 100.
• how many LEDs can be controlled at what speed by PIC controllers? (PIC bandwidth?)
• how much space (depth) to build this. The idea is it can sit in FRONT of a machine in a rack cabinet
  • remember to consider rKITT heatsink issues, and server case airflow issues!

[edit] further reading

• http://www.thinkgeek.com/clearance/c58c/ - a thinkgeek product with 18 LEDs
• Have seen 36white LEDs reading lamp on ebay. USB powered.

note that Arduino will make all of this much simpler, it just wasn't around when I first came up with the idea. This page is yet to be refactored with Arduinoness :)

• The CM-5 LED display
  • on wikipedia: https://en.wikipedia.org/wiki/Connection_Machine
  • someone recommissioned the display of one to their home: https://web.archive.org/web/20140408112433/http://www.housedillon.com/?p=1272
    • Some code they wrote is at https://pastebin.com/9xhxiHeL and https://pastebin.com/MZh9ing5 (I have saved local copies if pastebin goes awol)