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diff --git a/rsbusserv.erl b/rsbusserv.erl
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+%%%-------------------------------------------------------------------
+%%% @author Joe Zhao
+%%% @copyright (C) 2014, <COMPANY>
+%%% @doc
+%%% This server monitors behaviors on the serial bus.
+%%% Whose duty includes serialize queries, message encoding,
+%%%  and response handling(only when slave request repitition of the previous command)
+%%% The returns of the command are sent back to its origins(first parameter of the tuple, can also be someone else).
+%%% @end
+%%% Created : 27. 四月 2014 16:52
+%%%-------------------------------------------------------------------
+-module(rsbusserv).
+-author("Joe Zhao").
+
+-compile([debug_info,export_all]).
+
+%% API
+%% -export([start/0]).
+
+-define(DEVICE,"/dev/ttyUSB0").
+-define(SPEED,19200).
+-define(TIMEOUT,40). % Timeout in milisec
+-define(REQTIMEOUT,200).
+
+-define(STARTBIT,[16#5B,16#AD]).
+-define(STOPBIT,[16#A4,16#52]).
+-define(REP,16#FF).
+
+rsbuslistener(Pid) ->
+  SerialPort = serial:start([{speed,?SPEED},{open,?DEVICE}]),
+  register(?MODULE,self()),
+  rsbus_listner(Pid,SerialPort).
+
+rsbus_parity(Msg) ->
+  lists:foldl(fun (X,P) -> X bxor P end,0,Msg).
+
+rsbus_rec([],ok,Msg,[]) ->
+  {stat,lists:reverse(tl(Msg)),hd(Msg)};
+rsbus_rec([H1,H2|Tail],read,Msg,[H1,H2]) ->
+  rsbus_rec([],ok,Msg,[]);
+rsbus_rec([H1,H2,H3|Tail],read,Msg,Cmp) ->
+  rsbus_rec([H2,H3|Tail],read,[H1|Msg],Cmp);
+rsbus_rec([H1,H2,H3,H4|Tail1],wait,[],[H1,H2,H3,H4]) ->
+  rsbus_rec(Tail1,read,[],?STOPBIT);
+rsbus_rec([H|Tail],wait,[],Cmp) ->
+  rsbus_rec(Tail,wait,[],Cmp);
+rsbus_rec(Rec,State,Msg,Cmp) ->
+  receive
+    {data, Bytes} ->
+      erlang:display(binary_to_list(Bytes)),
+      rsbus_rec(Rec++binary_to_list(Bytes),State,Msg,Cmp)
+  after ?TIMEOUT ->
+    {error,timeout}
+  end.
+
+rsbus_send(SerialPort,Addr,Msg) ->
+  %% Return {stat,Type,Stat} upon success
+  %%    else return {error,timeout|parse}
+  SerialPort ! {send,?STARTBIT},
+  SerialPort ! {send,[Addr]},
+  SerialPort ! {send,Msg},
+  P=rsbus_parity(Msg) bxor Addr,
+  SerialPort ! {send,[P]},
+  SerialPort ! {send,?STOPBIT},
+  io:format("Send Complete!\n"),
+  case rsbus_rec([],wait,[],?STARTBIT++[0,Addr]) of
+    {stat,[?REP],RP} -> rsbus_send(SerialPort,Addr,Msg);  % Will resend no matter what
+    {stat,Stat,RP} ->
+      erlang:display(RP),
+      TestP =rsbus_parity([RP|Stat]),
+      if
+         TestP /= Addr -> {err,parse};
+        true ->  {stat,hd(Stat),tl(Stat)}
+      end;
+    {error,timeout} -> {error,timeout}
+  end.
+
+
+%% This function can effectively serialize access
+rsbus_listner(Pid,SerialPort) ->
+  erlang:display(self()),
+  receive
+    {data, _Bytes} ->
+      %% This shouldn't happen, no process should initiate comm
+      %% Discard everything
+      rsbus_listner(Pid,SerialPort);
+    {PPid,comm,Addr,Msg} ->
+      io:format("RSBus sending..."),
+      PPid ! {self(),device,Addr,rsbus_send(SerialPort,Addr,Msg)}, % Process and return
+      rsbus_listner(Pid,SerialPort);
+    {Pid,shutdown} ->
+      SerialPort ! stop,
+      ok
+  end.
+
+rsbusloop(Pid) ->
+  receive
+    {'EXIT',Pid,Cond} when Cond == normal; Cond==shutdown ->  rsbusloop(spawn_link(?MODULE,rsbuslistener,[self()]));
+    {PPid,shutdown} -> Pid ! {self(),shutdown}
+  end.
+
+rsbusmon() ->
+  process_flag(trap_exit,true),
+  Pid = spawn_link(?MODULE,rsbuslistener,[self()]),
+  rsbusloop(Pid).
+
+rsbusreq(Addr,Msg) ->
+  rsbusserv ! {self(),comm,Addr,Msg},
+  receive
+    {PPid,device,Addr,{error,Reason}} ->
+      {error,Reason};
+    {PPid,device,Addr,{stat,Type,Msg}} ->
+      {stat,Type,Msg}
+  after ?REQTIMEOUT ->
+    {error,timeout}
+  end.
+
+start() ->
+  spawn(?MODULE,rsbusmon,[]).
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