unit comUSB;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, crt,serial;

 function getserialport:longint;
 procedure initUSB(shandler:longint);
 procedure closeUSB;
 function startUSB:longint;
 function getUSB(t:longint):string;
 procedure sendUSB(s:string);

 var device:string;

implementation

uses mainunit;

var
  serialhandler : LongInt;
  Parity       : TParityType; { TParityType = (NoneParity, OddParity, EvenParity); }
  StopBits     : Integer;
  Flags        : TSerialFlags; { TSerialFlags = set of (RtsCtsFlowControl); }






function getUSB(t:longint):string;

var
  s:String=' ';
  status:longint=0;
  x:String;
  i:longint=0;
  ss:byte;

  begin
   getUSB:='';
   if serialhandler<0 then exit;
   while (Length(x)<50) and (status>=0) do
      begin
          status:= SerRead(serialhandler, ss, 1);
          if status=0 then begin sleep(1); inc(i); end;
          if (ss=10) then status:=-1;
          if (status>0) then
            begin
             i:=0;
             if ss<>13 then x:=x+chr(ss);
            end;
          if i>t then
            begin
             getUSB:='timeout';
             exit;
            end;
      end;
   getUSB:=x;
  end;


procedure sendUSB(s:string);

var
  writecount:longint;
  status:longint;
  ss:string;

begin
 writecount := length(s)+1;
 ss:=s+chr(10);
 status := SerWrite(serialhandler, ss[1], writecount );
end;

procedure initUSB(shandler:longint);

var
  status:longint=0;
  x:String;
  i:longint;
  ss:byte;

begin
    sleep(1000);
    while (Length(x)<2000) and (status>=0) do
      begin
          status:= SerRead(shandler, ss, 1);
          if status=0 then begin sleep(1); inc(i);  end;
          //if (status>0) then writeln(ss);
          if (status>0) then x:=x+chr(ss);
          if i>1000 then
            begin
              exit;
            end;
      end;
end;

function getpeltier:longint;

var s:string;

begin
   Flags:= [ ]; // None
   SerSetParams(serialhandler,115200,8,NoneParity,1,Flags);
   initUSB(serialhandler);
   sendUSB('RESET');
   sleep(3000);
   s:=getUSB(10000);
   //writeln(s);
   if pos('Peltier',s)<>0 then
       begin
         //Writeln(s);
         s:=getUSB(5000);
         getpeltier:=0;
         paramout;
         exit;
       end;
   closeUSB;
   getpeltier:=-1;
end;

function ss(dev:string):longint;

begin
  serialhandler:=SerOpen(dev);
  if serialhandler>0 then
    if getpeltier=0 then
        begin
          device:=dev;
          ss:=serialhandler;
          exit;
        end;
  ss:=-1;
end;


function getserialport:longint;

  var s:string;
      dev:string;

  begin
{$ifdef Linux}
     dev:='/dev/ttyACM0';
{$else}
     dev:='COM3';
{$endif}
     getserialport:=ss(dev); if getserialport>0 then exit;
{$ifdef Linux}
     dev:='/dev/ttyACM1';
{$else}
      dev:='COM4';
{$endif}
     getserialport:=ss(dev); if getserialport>0 then exit;
{$ifdef Linux}
      dev:='/dev/ttyACM2';
{$else}
      dev:='COM5';
{$endif}
     getserialport:=ss(dev); if getserialport>0 then exit;
{$ifdef Linux}
      dev:='/dev/ttyACM3';
{$else}
          dev:='COM6';
{$endif}
     getserialport:=ss(dev); if getserialport>0 then exit;
     getserialport:=-1;
     end;


function startUSB:longint;

var
  s:string;

begin
   if getserialport<0 then
     begin
       startUSB:=-1;
       exit;
     end;
  startUSB:=0;
end;


procedure closeUSB;

begin
 SerSync(serialhandler); { flush out any remaining before closure }
 SerFlushOutput(serialhandler); { discard any remaining output }
 SerClose(serialhandler);
end;

end.