[ts-7000] 7400 question using DIO

["mrjbradski" <>]

Im just experimenting with DIO before I actually need to use it, so I
wrote a simple program to toggle the DIO0..7 pins as follows:

        fd = open("/dev/mem", O_RDWR|O_SYNC);
        gpioregs = (char *)mmap(0, 4096, PROT_READ|PROT_WRITE, MAP_SHARED,fd,
0x12c00000);
        gpioregs[0] = 0xff; /* data direction register set to all outputs */
        
        for (;;) {
                gpioregs[2] = 0xff; /* output high to DIO_01 and DIO_4, all 
else low */
                gpioregs[2] = 0x0; /* output high to DIO_01 and DIO_4, all else 
low */
        }
        close(fd);
        exit(0);

For some reason, the pins never toggle. If I remove the for loop, and
execute gpioregs[2] = 0xff; OR gpioregs[2] = 0x0; the pins will change
state. What am I doing wrong?

Rich



 
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