Re: Hello, and help with GNAT and Windows USB programming

["björn lundin" <b.f.lundin@gmail.com>]

Den söndagen den 9:e februari 2014 kl. 20:59:41 UTC+1 skrev Gumpy:
> 2. Using GNAT, and potentially GNAT.Serial_Communications, how does one open >a USB port and read and write character strings to it (the thermocouple >interface has a simple character based command language for setup and taking >temperature readings). 

if the card is using serial comm, then you want to by a usb-to-serial converter.
It will act like a virtual com-port then
Use it like this (the code spoke with an Arduaino) 

with GNAT.Serial_Communications;
with Ada.Streams;
procedure Serial_Talker is
  TTY : GNAT.Serial_Communications.Serial_Port;
  ------------------------
  function String_To_Stream ( The_String : in String) return Ada.Streams.Stream_Element_Array is
    Return_Value : Ada.Streams.Stream_Element_Array(1..The_String'length);
  begin
    for Count in 1..Ada.Streams.Stream_Element_Offset(The_String'Length) loop
       Return_Value(Count) := Character'pos(The_String(Integer(Count)));
    end loop;
    return Return_Value(1..The_String'Length);
  end String_To_Stream;
  ------------------------
begin
 TTY.Open(Name => "/dev/ttyUSB0");
 TTY.Set (Rate      => GNAT.Serial_Communications.B9600,
          Bits      => GNAT.Serial_Communications.CS8,
          Stop_Bits => GNAT.Serial_Communications.One,
          Parity    => GNAT.Serial_Communications.None,
          Block     => True);
 TTY.Write(Buffer => (String_To_Stream("1"))); -- whatever you'd like
 TTY.Close;
end Serial_Talker;


need -gnat05 to compile

it was on Linux, and on Win
 TTY.Open(Name => "/dev/ttyUSB0");
would be like
 TTY.Open(Name => "COM4");
or perhaps 
 TTY.Open(Name => "COM4:");
or 
 TTY.Open(Name => "\\.\COM4");
or 
 TTY.Open(Name => "\\\\.\\COM4");


But i'm not sure you'd use serial comm though.

I have a velleman k8055
<http://www.velleman.eu/products/view/?country=be&lang=en&id=351346>
which I interfaced with bundled dlls.
No serial comm at all.
It involved looping around the usb devices and finding the card, with
id of manufacturer etc.

I have it on a broken machine, but I might be able to dig it up tomorrow,
if you think it will help
> 
> 3. Does anyone have any specific code examples for communicating on a USB >port that they would like to share, or a link to some example(s) online >somewhere? 
 
yes, as above


/Björn