No response to Command Ctrl codes in '634

David Smith

New member

Using a '634 v2.3, using CCS C

My display responds correctly to ctrl-M,J,L putc(13), putc(10) putc(12)....
but the other codes seem to have no effect.
For example: putc(4) should hide cursor... \004 = CTRL-D
Is there some add'l code I must transmit?

(I could find no embedded C code sample online, nor a reference in the data sheet).
       putc(' ');   //
       putc(4);    // hide cursor
       clrscrn();   // sends ctrl-L
       printf("* Test *\n\r");
Thank you.
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.
USB LCD Displays - Graphic and Character LCDs with a Keypad

CF Tech

Usually this kind of issue is related to the OS processing the serial stream.

What OS are you using? If it is Linux, the following page may help:

This bit sounds helpful:
      cfmakeraw() sets the terminal attributes as follows:
          termios_p->c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
                          | INLCR | IGNCR | ICRNL | IXON);
          termios_p->c_oflag &= ~OPOST;
          termios_p->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
          termios_p->c_cflag &= ~(CSIZE | PARENB);
          termios_p->c_cflag |= CS8;
(sorry for being vague, but it has been ages since I last did something like this under Unix)