Embedded Development Tools

[wangf]

I try to input character from console, I use standard C function, getchar(), but it does not works properly,

first, it is especially large, second, it can get character back only after I push return key, It is not the way as in standard C.

What is wrong, and how can I input character? Must I use XUartLite_RecvByte() ? I'd like to use standard C functions to make the program easy.

test_id = getchar();
switch (test_id)
 {
    case '1':
     print("input 1\n");
     break;
    case '2':
     print("input 2\n");
     break;
    case '3':
     print("input 3\n");
     break;
    case 'C':
     print("input C\n");
     break;
    default:
     print("wrong enter");
     break;
   }

[bassman59]

Your terminal program might not send the characters until it sees that you've hit ENTER.

-a

[wangf]

my terminal program is SecureCRT, and it works well with others embedded system. Also I tried HyperTerminal, it works in same way.

so, do anyone use getchar() successfuly before?  and Must I turn to xilinx uart api?  Thanks.

(My tools and envirorment is Microblaze, EDK92, uartlite v1.0)

[golson]

I did a search on getchar and EDK.  Other people have been using it according to search in Xilinx Forum.

http://www.xilinx.com/support/answers/29379.htm

and

http://warp.rice.edu/trac/browser/trunk/EDK/LEDs/Demo1.c?rev=56

http://forums.xilinx.com/xlnx/board/message?board.id=EMBEDDED&message.id=876&query.id=392564#M876

http://forums.xilinx.com/xlnx/board/message?board.id=EDK&message.id=4510&query.id=392610#M4510

Try increasing Heap and Stack Size a lot to see if that is the problem.

Message Edited by golson on 12-17-2008 10:17 AM

[ralfcantnerbosch · Accepted solution]

Hi together,

I had the same problem.

You can change the buffering behaviour of stdin by calling

setvbuf() before calling getchar();

Example :

setvbuf(stdin, NULL, _IONBF, 0);

for (;;)

{

  Input = getchar();

  if (Input != EOF)

    xil_printf("%c", Input);

}

You may omit the line with EOF, I never got that value.

I have tested the code above with XMK, it should work

in a standalone version too.

BTW: Hyperterminal sends each character as soon as you type it.

It does not wait for the <RETURN> key.

Hope this helps

  Ralf

[wangf]

Your method works. But it seems that the getchar() function is huge! I decided to use xilinx's api, and deal with all the input myself.

Still, many thanks for your reply.