added multicast reception in the udp effect (#675)

* Removed -HUP so the default -TERM signal is sent instead.
- hyperiond only listens for TERM and INT. HUP is often used to get an exe to reread its config

Changed pgrep to add '-x' so it wont partial match on the exe name.
- I have multiple instances with multiple hyperiond-instance1 names
- this ensures the service script only kills the right process

* reversing errant change to hyperion.systemd.sh

* cleaned up a couple of compiler warnings

* moved bitpair_to_byte initialiser to (hopefully) work with older GCC

* compiler warning in udp driver
removed some tabs in ws2812b.cpp

* formatting - spaces to tabs

* moved rpi_281x to tag sk6812-v1.0

* moving to my fork of rpi_281x

* removed dos line endings

* Found some more "dos" line ending files

* Added multicast support to the udp listener "effect"

* the default udp.json will listen to unicast on port 2391 (as it used to)

the new udp-mcast.json will listen on multicast 239.255.28.01:2801


Former-commit-id: 5c76fab

effects/udp-mcast.json

@@ -0,0 +1,9 @@
+{
+	"name" : "UDP multicast listener",
+	"script" : "udp.py",
+	"args" :
+	{
+		"ListenPort" : 2801,
+		"ListenIP" : "239.255.28.01" 
+	}
+}

effects/udp.json

@@ -1,8 +1,8 @@
-{
-	"name" : "UDP listener",
-	"script" : "udp.py",
-	"args" :
-	{
-		"udpPort" : 2391 
-	}
-}
+{
+	"name" : "UDP listener",
+	"script" : "udp.py",
+	"args" :
+	{
+		"ListenPort" : 2391
+	}
+}

effects/udp.py

@@ -3,17 +3,33 @@
 import colorsys
 import socket
 import errno
+import struct 
 
 # Get the parameters
-udpPort = int(hyperion.args.get('udpPort', 2812))
+ListenPort = int(hyperion.args.get('ListenPort', 2801))
+ListenIP = hyperion.args.get('ListenIP', "")
+octets = ListenIP.split('.');
 
-UDPSock = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
+UDPSock = socket.socket(socket.AF_INET,socket.SOCK_DGRAM, socket.IPPROTO_UDP)
 UDPSock.setblocking(False)
 
-listen_addr = ("",udpPort)
-print "udp.py: bind socket port:",udpPort
+listen_addr = (ListenIP,ListenPort)
 UDPSock.bind(listen_addr)
 
+if ListenIP == "":
+	print "udp.py: Listening on *.*.*.*:"+str(ListenPort)
+else:
+	print "udp.py: Listening on "+ListenIP+":"+str(ListenPort)
+
+if len(octets) == 4 and int(octets[0]) >= 224 and int(octets[0]) < 240:
+	print "ListenIP is a multicast address\n"
+	# Multicast handling
+	try:
+		mreq = struct.pack("4sl", socket.inet_aton(ListenIP), socket.INADDR_ANY)
+		UDPSock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
+	except socket.error:
+		print "ERROR enabling multicast\n"
+
 hyperion.setColor(hyperion.ledCount *  bytearray((int(0), int(0), int(0))) )
 
 # Start the write data loop