initial import

Author: letoram

README.md

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+These are various hacked-up projects that use the pipe-
+fifo LED protocol as part of arcan >= 0.5.2.
+
+# Subprojects
+  g810 - GPLv3, see README.md and LICENSE file. Adds support
+	       for reading protocol controls via stdin.
+
+  arduino - arduino project and makefiles for programming an
+	          arduino device to use the protocol over serial or
+						i2c in order to control PWM adafruit neopixel- LEDs.
+
+# Setup/Use
+
+fifos can be configured via:
+
+    mkfifo c /path/to/fifo
+		mkfifo c /path/to/fifo2
+    arcan_db add_appl_kv arcan ext_led /path/to/fifo
+    arcan_db add_appl_kv arcan ext_led_2 /path/to/fifo2
+
+and so on.
+
+for the arduino setup, the USB- serial port can be configured like:
+
+    stty -F /dev/ttyACM0 cs8 9600 ignbrk -brkint -imaxbel -opost
+		 -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl
+		 -echoke noflsh -ixon -crtscts
+
+and then fed like:
+
+    cat /path/to/fifo > /dev/ttyACM0
+
+the g810 module, similarly:
+
+    cat /path/to/fifo | g810-led --arcan-stdin
+
+# Protocol
+
+Each packet is a 2-byte tuple of opcode and argument.
+
+first byte is one of (ascii) 'A' 'a' 'r' 'g' 'b' 'i' 'c' or 'o'.
+
+'A' [ign] : set active LED index to 'all'
+'a' [num] : set active LED index to [num]
+'r' [num] : set current Red value to [num]
+'g' [num] : set current Green value to [num]
+'b' [num] : set current Blue value to [num]
+'i' [num] : set all (Red, Green, Blue) value to [num]
+'c' [num] : num = 0, commit - no buffer, > 0 - buffer
+
+with the buffer indication meaning that more values are to come before
+any update to led devices should be pushed.
+
+The arcan scripts can then use set\_led\_rgb(dev, ind, r, g, b, buf) calls
+to emit data to the respective devices. Advanced such use can be found in
+[durden](https://github.com/letoram/durden) iostatem.lua + devmaps/led/...
+
+devmaps/ contain example such devmaps for the setup shown above. A video
+of its use can be found at [gfycat](https://gfycat.com/AgonizingPleasingGuppy)
+