timer05.c

////////////////////////////////////////////////////////////////////////////////
//     
//    __                                ______
//   / /_______________  ____  ___     / ____/
//  / __/ ___/ ___/ __ \/ __ \/ _ \   /___ )  
// / /_(__  ) /__/ /_/ / /_/ /  __/  ____/ /  
// \__/____/\___/\____/ .___/\___/  /_____/   
//                   /_/                      
//     
// timer05.c
// - Change the stimulus while waiting for a response.
// - Instructions: press S when an S appears, press L when an L appears.
////////////////////////////////////////////////////////////////////////////////


#include <tscope5.h>

int main()
{
    // open a display
    ts5_install_display();
    ts5_wait(2.0);
    
    // define response buttons
    ts5_define_keyboard_button(TS5_KEY_S);
    ts5_define_keyboard_button(TS5_KEY_L);
        
        
    double start, stop, rt, error;
    int i;
    
    for (i=0; i<5; i++) {
        
        // fixation
        ts5_clear_display();
        ts5_printf(0.0, 0.0, "+");
        ts5_flip_display();
        ts5_wait(0.5);

        // stimulus
        unsigned int stim = ts5_random_integer(2);
        if (stim==0) {
            stim='S';
        }
        else {
            stim='L';
        }
        ts5_clear_display();
        ts5_printf(0.0, 0.0, "%c", stim);
        start = ts5_flip_display();

        // flush the response buffer after stimulus onset
        ts5_flush_responses();
        
        // clear the display after 0.5 seconds
        // if a response occurs during this interval it is buffered
        ts5_wait(0.5);
        ts5_clear_display();
        ts5_flip_display();
        
        // wait until 2 seconds after the stimulus  
        int resp = ts5_wait_for_response_until(&stop, &error, start + 2.0);
        
        // compute and print RT
        rt = stop-start;
        ts5_clear_display();
        ts5_printf(0.0, 20.0, "response %d", resp);
        ts5_printf(0.0, 0.0, "rt %f", rt);
        ts5_printf(0.0, -20.0, "measurement error %f", error);
        ts5_flip_display();
        
        // iti
        ts5_wait(2.0);      
    }
    
    // wait for a click
    ts5_draw_mouse_button(ax(0.9), ay(-0.8));   
    return 0;
}