Rewrote devices on Beaglebone. Passes precompile, but needs proper testing.

src/BeagleBone/SysLED.jl

@@ -5,7 +5,7 @@ i ∈ [1,2,3,4].
 """
 type SysLED <: IO_Object
     i::Int32
-    brightness_filestream::IOStream
+    filestream::IOStream
     function SysLED(i::Int32)
         i ∉ [1,2,3,4] && error("Invalid SysLED index: $i")
         #Note, in the future we should interface to config and retrieve IOStream from there
@@ -18,10 +18,11 @@ end
     write!(led::SysLED, val::Bool, debug::Bool=false)
 Turns the LED 'SysLed' on/off for val = true/false respectively.
 """
-function write!(led::SysLED, val::Bool, debug::Bool=false)
+function write!(led::SysLED, entry::String, debug::Bool=false)
     debug && return
-    write(led.brightness_filestream, val ? "1" : "0")
-    seekstart(led.brightness_filestream)
+    entry ∉ ["0", "1"] && error("Invalid SysLED entry $(entry), valid options are 0 and 1 (string)")
+    write(led.filestream, entry)
+    seekstart(led.filestream)
 end
 
 """
@@ -30,9 +31,9 @@ Reads the current brightness value from the LED 'SysLED'.
 """
 function read(led::SysLED, debug::Bool=false)
     debug && return
-    l = read(led.brightness_filestream, Char)
+    l = read(filestream, Char)
     (l != '1' && l != '0') && error("Invalid value \"$l\" read from SysLed")
-    seekstart(led.brightness_filestream)
+    seekstart(led.filestream)
     return l
 end
 
@@ -42,5 +43,5 @@ Closes all open filestreams for the SysLED 'led'.
 """
 function teardown(led::SysLED, debug::Bool=false)
     debug && return
-    close(led.brightness_filestream)
+    close(led.filestream)
 end