How to read Rotary encoder pulses?

**gazel** · 27th August 2010, 11:16

Hi,
I am new to this forum and QT applications. i hope the message is in right place.

i have an ARM9 development board running linux on it. without using GUI i can use all devices on the board like hardware buttons (as interrupts), ADCs, eeproms etc...

For external buttons, Ä± use this example (simply)

Qt Code:

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fd = open("/dev/button", 0);
	if (fd < 0) {
		perror("error open device");
		exit(1);
	}
 
	for (;;)
 
{
		char buttons[3];
 
		read(fd, buttons, sizeof buttons);
 printf("%s %s %s", buttons[0] , buttons[1] , buttons[2] );
 
		}

fd = open("/dev/button", 0);
	if (fd < 0) {
		perror("error open device");
		exit(1);
	}

	for (;;)
                        
{
		char buttons[3];
		
		read(fd, buttons, sizeof buttons);
 printf("%s %s %s", buttons[0] , buttons[1] , buttons[2] );
			
		}

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this prints the buttons state as 0 or 1

How can i implement this to GUI. how can i read device data continuesly in a fast way? i want to connect a rotary encoder and count the number of pulses. using the console applÄ±cation no problem but how can i make this using QT?

thank you