1 files changed, 130 insertions, 0 deletions
diff --git a/daemon.py b/daemon.py
new file mode 100755
index 0000000..a66c8c5
--- /dev/null
+++ b/daemon.py
@@ -0,0 +1,130 @@
+#!/usr/bin/python
+
+import serial
+import mpd
+import time
+import sys
+
+class Config:
+    display_lines = 2
+    display_width = 16
+    display_length = display_lines * display_width
+
+class Daemon:
+    line = ""
+    playing = False
+
+    def __init__(self):
+        self.ser = serial.Serial(sys.argv[1], 9600, timeout=1)
+
+        # raise timeout to let arduino start up
+        self.ser.timeout = 15
+        incoming = self.readline()
+
+        # arduino sometimes has a dirty buffer
+        # and sends junk before the ready message
+        if not incoming.endswith("ready"):
+            sys.stderr.write("Got unexpected reply: "+incoming)
+            raise Exception("Wrong client greeting")
+        self.ser.timeout = 1
+
+        self.client = mpd.MPDClient()
+        self.client.connect("localhost", 6600)
+
+    def readline(self):
+        return self.ser.readline().decode("ascii").strip()
+
+    def update(self):
+        old_line = self.line
+        old_playing = self.playing
+        changed = False
+
+        incoming = self.client.currentsong()
+
+        self.line = incoming["artist"] + " - " + incoming["title"]
+        if self.line != old_line:
+            changed = True
+
+        self.playing = self.client.status()["state"] == "play"
+        if self.playing != old_playing:
+            changed = True
+
+        return changed
+
+    def run(self):
+        self.update()
+
+        last_display_update = 0.0
+        last_song_update = 0.0
+        now = 0.0
+        time_diff = 0.0
+        current_position = 0
+
+        while 1:
+            now = time.time()
+
+            # check for incoming commands from arduino
+            if self.ser.inWaiting() > 0:
+                incoming = self.readline()
+
+                functions = {
+                    "next": self.client.next,
+                    "previous": self.client.previous,
+                    "pause": self.client.pause,
+                }
+                try:
+                    func = functions[incoming]
+                    func()
+
+                    # force redraw if anything changed
+                    if self.update():
+                        last_display_update = 0
+                        current_position = 0
+
+                except KeyError:
+                    pass
+
+            # check if song changed
+            # TODO: use idle and poll (more often)?
+            time_diff = now - last_song_update
+            if time_diff > 2.5 or time_diff < -60.0:
+                last_song_update = now
+                if self.update():
+                    last_display_update = 0
+                    current_position = 0
+
+            # update arduino display
+            time_diff = now - last_display_update
+            if time_diff > 0.8 or time_diff < -60.0:
+                last_display_update = now
+                if self.playing:
+                    i = current_position
+
+                    if i - 1 + Config.display_length == len(self.line):
+                        i = 0
+
+                    if i == 0:
+                        # allow people to start reading
+                        last_display_update += 2
+
+                    if len(self.line) > Config.display_length:
+                        buf = self.line[i:i+Config.display_length]
+                    else:
+                        buf = self.line.ljust(Config.display_length, " ")
+
+                    i += 1
+                    current_position = i
+                else:
+                    buf = "-- PAUSED --".center(Config.display_width, " ").ljust(Config.display_length, " ")
+
+                    # always start at the beginning if we unpause
+                    current_position = 0
+
+                print("'" + buf + "'")
+                self.ser.write(bytes(buf, "ascii", "replace"))
+
+            time.sleep(0.05)
+
+if __name__ == '__main__':
+    d = Daemon()
+    d.run()