you should watch this video => https://www.youtube.com/watch?v=wui_wU1AeQc Enjoy,
On Wed, Feb 12, 2014 at 1:14 PM, matt <[email protected]> wrote: > Hi, > > I got a BBB. > > I connected a LED to its GPIO1_16 pin, which I tried to turn on and off > using the GPIO configuration in the code below. > > For some reason the LED does not turn ON. > > When I use the same GPIO pin, but using the Virtual File System code to > turn on the LED, it works. > > Therefore I guess i'm missing something with the below code. > > Do you spot any problem? > > Thanks a lot. > > #define GPIO1_BASE 0x4804C000 // Start Address > #define GPIO1_END 0x4804D000 // End Address > #define GPIO1_SIZE GPIO_END - GPIO_BASE > #define GPIO_OE 0x0134 // Offset > #define GPIO_DATAOUT 0x013C // Offset > #define GPIO1_16 16 > > > int main(int argc, char** argv) > { > volatile unsigned int *reg_base, *reg_oe, *reg_out; > unsigned int value; > int fd; > > > //open mem file for Read and Write > fd = open("/dev/mem", O_RDWR); > if (fd == -1) > { > perror("Unable to open /dev/mem"); > exit(EXIT_FAILURE); > } > > > /* LED Setup and Turn-on */ > reg_base = mmap(0, GPIO1_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, > fd,GPIO_BASE > ); > > //Set GPIO to Output > reg_oe = (volatile unsigned int*)(reg_base + GPIO_OE); > value = *(reg_oe); > value &= ~(1 << GPIO1_16); > *(reg_oe) = value; > > > //turn on GPIO > reg_out = (volatile unsigned int*)(GPIO1_16 + GPIO_DATAOUT); > value = *(reg_out); > value |= (1 << GPIO1_16); > *(reg_out) = value; > > > return 0; > } > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
