Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

--- projekte:mikubox [2017/02/24 21:57] – [MikuBox: Pseudoholographic projection box] da1l6
+++ projekte:mikubox [2017/05/18 06:48] (aktuell) – [MikuBox: Pseudoholographic projection box] da1l6
@@ Zeile 23: / Zeile 23: @@
 === Construction ===
+{{ :projekte:mikuboxschema2.png?directdirect&300|Construction}}
+The MikuBox is constructed around an off-the-shelf 21.5" 1080p PC Monitor and is made out of MDF.
+The monitor of choice uses a VA-LCD Panel to provide better black levels than standard TN-Panels. It also does not suffer from IPS-Glow. It is, however, view angle dependent. Ideally an OLED-Panel or other self illuminating pixel display would be used, but these were unobtainbale at time of construction.
-The Mikubox is constructed around an off-the-shelf 21.5" LCD and is made out of MDF.
+The dimensions of the box are derived from the monitor. It is important that some depth (a) is added to the box compared to the distance between bottom and LCD (h). This distance will be the precived distance between background and projection.
-The Monitor of Choice uses a VA-LCD Panel to provide better Black Levels than standard TN Panels. It also does not suffer from IPS-Glow. Ideally an OLED Panel or other self illuminating pixel display should be used, but these were unobtainbale at time of writing.
-The dimensions of the box are derived from the Monitor. It is important the some depth (a) is added to the box compared to the distance between bottom and LCD (h). This distance will be the precived distance between background and projection.
+The background is made out of unused scrap PCBs with dark blue soldermask. It is illuminated by stray light only.
+It is not nessacary to use a background, but it will improve the 3D effect. A patterned background is recommended as it will make the parallax effect more obvious.
+A background too bright will shine through dark parts of the projection, so it should be avoided if such content is to be projected.
+Extra height (b) is added to house the electronics and cables. A RaspberryPi 1 is internally connected to the LCD monitor via HDMI. Ethernet, Analog Audio and Power are routed to the back.
+=== Software ===
+The RaspberryPi inside the box run standard a Raspberian Lite (Debian based) OS without GUI. Video Playbay is done by omxplayer, which uses the Hardware video decoder of the rPi SoC.
+A systemd unit file is added to the end of the Boot process to run a video playback script.
+Unit File
+<code>
+[Unit]
+Description=Video demo loop
+After=network.target
+[Service]
+Type=simple
+User=root
+ExecStart=/home/pi/mmd/demo.rb
+[Install]
+WantedBy=multi-user.target
+</code>
+Video playback script:
+<code>#!/usr/bin/env ruby
+require "timeout"
+require "fileutils"
+Dir.chdir(File.dirname($0))
+while true
+	Dir.glob("*.mp4").shuffle.each{|filename|
+		puts ".... Playing #{filename} ...."
+		system("/usr/bin/omxplayer", "-r", "--no-osd", filename)
+	}
+end
+</code>