diff -r c53985209d09 source/event_gpio.c
--- a/source/event_gpio.c	Sun Oct 30 22:41:09 2016 +0000
+++ b/source/event_gpio.c	Thu Feb 23 18:22:28 2017 +0100
@@ -24,6 +24,7 @@
 #include <sys/epoll.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <unistd.h>
@@ -62,17 +63,64 @@
 int thread_running = 0;
 int epfd_thread = -1;
 int epfd_blocking = -1;
+int pin_base = -1;
 
 /************* /sys/class/gpio functions ************/
+void gpio_find_chip_base()
+{
+    DIR *gpio_dir;
+    struct dirent *child;
+    char label_path[128];
+    char label[128];
+    int fd;
+
+    /* No need to search for it twice */
+    if (pin_base >= 0)
+        return;
+
+    if ((gpio_dir = opendir("/sys/class/gpio")) == NULL) {
+        pin_base = 0;
+        return;
+    }
+
+    while ((child = readdir(gpio_dir)) != NULL) {
+        if (!strstr(child->d_name, "gpiochip"))
+            continue;
+
+        if (snprintf(label_path, sizeof(label_path),
+                     "/sys/class/gpio/%s/label", child->d_name) < 0) {
+            pin_base = 0;
+            return;
+        }
+
+        if ((fd = open(label_path, O_RDONLY)) < 0) {
+            pin_base = 0;
+            return;
+        }
+
+        if (read(fd, label, sizeof(label)) > 0 &&
+            strstr(label, "pinctrl-bcm2835")) {
+            pin_base = atoi(child->d_name + 8);
+            break;
+        }
+        close(fd);
+    }
+
+    if (pin_base < 0)
+        pin_base = 0;
+}
+
 int gpio_export(unsigned int gpio)
 {
     int fd, len;
-    char str_gpio[3];
+    char str_gpio[64];
 
     if ((fd = open("/sys/class/gpio/export", O_WRONLY)) < 0)
        return -1;
 
-    len = snprintf(str_gpio, sizeof(str_gpio), "%d", gpio);
+    gpio_find_chip_base();
+
+    len = snprintf(str_gpio, sizeof(str_gpio), "%d", pin_base + gpio);
     write(fd, str_gpio, len);
     close(fd);
 
@@ -82,12 +130,14 @@
 int gpio_unexport(unsigned int gpio)
 {
     int fd, len;
-    char str_gpio[3];
+    char str_gpio[64];
 
     if ((fd = open("/sys/class/gpio/unexport", O_WRONLY)) < 0)
         return -1;
 
-    len = snprintf(str_gpio, sizeof(str_gpio), "%d", gpio);
+    gpio_find_chip_base();
+
+    len = snprintf(str_gpio, sizeof(str_gpio), "%d", pin_base + gpio);
     write(fd, str_gpio, len);
     close(fd);
 
@@ -99,9 +149,11 @@
     int retry;
     struct timespec delay;
     int fd;
-    char filename[33];
+    char filename[64];
 
-    snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/direction", gpio);
+    gpio_find_chip_base();
+
+    snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/direction", pin_base + gpio);
 
     // retry waiting for udev to set correct file permissions
     delay.tv_sec = 0;
@@ -126,9 +178,11 @@
 int gpio_set_edge(unsigned int gpio, unsigned int edge)
 {
     int fd;
-    char filename[28];
+    char filename[64];
 
-    snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/edge", gpio);
+    gpio_find_chip_base();
+
+    snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/edge", pin_base + gpio);
 
     if ((fd = open(filename, O_WRONLY)) < 0)
         return -1;
@@ -141,10 +195,12 @@
 int open_value_file(unsigned int gpio)
 {
     int fd;
-    char filename[29];
+    char filename[64];
+
+    gpio_find_chip_base();
 
     // create file descriptor of value file
-    snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/value", gpio);
+    snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/value", pin_base + gpio);
     if ((fd = open(filename, O_RDONLY | O_NONBLOCK)) < 0)
         return -1;
     return fd;