Hardware Reference
In-Depth Information
#ifndef _BEAGLEBONE_GPIO_H_
#define _BEAGLEBONE_GPIO_H_
#define GPIO0_START_ADDR 0x44e07000
#define GPIO0_END_ADDR 0x44e08000
#define GPIO0_SIZE (GPIO0_END_ADDR - GPIO0_START_ADDR)
#define GPIO1_START_ADDR 0x4804C000
#define GPIO1_END_ADDR 0x4804D000
#define GPIO1_SIZE (GPIO1_END_ADDR - GPIO1_START_ADDR)
#define GPIO2_START_ADDR 0x41A4C000
#define GPIO2_END_ADDR 0x41A4D000
#define GPIO2_SIZE (GPIO2_END_ADDR - GPIO2_START_ADDR)
#define GPIO3_START_ADDR 0x41A4E000
#define GPIO3_END_ADDR 0x41A4F000
#define GPIO3_SIZE (GPIO3_END_ADDR - GPIO3_START_ADDR)
#define GPIO_DATAIN 0x138
#define GPIO_SETDATAOUT 0x194
#define GPIO_CLEARDATAOUT 0x190
#define GPIO_03 (1<<3)
#define GPIO_07 (1<<7)
#define GPIO_31 (1<<31)
#define GPIO_60 (1<<28)
#endif
Add the code in
Example 8-4
to a file named
pushLEDmmap.c
.
Example 8-4. Code for directly reading memory addresses (pushLEDmmap.c)
// From: http://stackoverflow.com/questions/13124271/
driving-beaglebone-gpio
// -through-dev-mem
// user contributions licensed under cc by-sa 3.0 with attribution
required
// http://creativecommons.org/licenses/by-sa/3.0/
// http://blog.stackoverflow.com/2009/06/attribution-required/
// Author: madscientist159 (http://stackoverflow.com/users/3000377/
madscientist159)
//
// Read one gpio pin and write it out to another using mmap.
// Be sure to set -O3 when compiling.
#include <stdio.h>
#include <stdlib.h>
