diff --git a/include/board.h b/include/board.h
new file mode 100644
index 0000000..b67ab45
--- /dev/null
+++ b/include/board.h
@@ -0,0 +1,8 @@
+#ifndef __BOARD_H__
+#define __BOARD_H__
+
+#ifdef BOARD_PCA10040
+#include "platform/narf52/narf52_dk.h"
+#endif
+
+#endif
diff --git a/include/platform/narf52/narf52_dk.h b/include/platform/narf52/narf52_dk.h
index 2fa3a03..312e300 100644
--- a/include/platform/narf52/narf52_dk.h
+++ b/include/platform/narf52/narf52_dk.h
@@ -6,7 +6,8 @@
 
 #include "driver.h"
 
-struct narf52_gpio narf_led_1 = {
+// LEDs
+const struct narf52_gpio narf_led_1 = {
     .pin_number = 17,
     .dir = NARF_GPIO_DIR_OUT,
     .input = NARF_GPIO_PIN_INPUT_DISCONNECT,
@@ -15,13 +16,13 @@ struct narf52_gpio narf_led_1 = {
     .sense = NARF_GPIO_PIN_NOSENSE,
 };
 
-struct driver led_1 = {
+const struct driver led_1 = {
     .name = "LED_1",
     .fp = &gpio_fp,
     .dev = (void *)&narf_led_1,
 };
 
-struct narf52_gpio narf_led_2 = {
+const struct narf52_gpio narf_led_2 = {
     .pin_number = 18,
     .dir = NARF_GPIO_DIR_OUT,
     .input = NARF_GPIO_PIN_INPUT_DISCONNECT,
@@ -30,13 +31,13 @@ struct narf52_gpio narf_led_2 = {
     .sense = NARF_GPIO_PIN_NOSENSE,
 };
 
-struct driver led_2 = {
+const struct driver led_2 = {
     .name = "LED_2",
     .fp = &gpio_fp,
     .dev = (void *)&narf_led_2,
 };
 
-struct narf52_gpio narf_led_3 = {
+const struct narf52_gpio narf_led_3 = {
     .pin_number = 19,
     .dir = NARF_GPIO_DIR_OUT,
     .input = NARF_GPIO_PIN_INPUT_DISCONNECT,
@@ -45,13 +46,13 @@ struct narf52_gpio narf_led_3 = {
     .sense = NARF_GPIO_PIN_NOSENSE,
 };
 
-struct driver led_3 = {
+const struct driver led_3 = {
     .name = "LED_3",
     .fp = &gpio_fp,
     .dev = (void *)&narf_led_3,
 };
 
-struct narf52_gpio narf_led_4 = {
+const struct narf52_gpio narf_led_4 = {
     .pin_number = 20,
     .dir = NARF_GPIO_DIR_OUT,
     .input = NARF_GPIO_PIN_INPUT_DISCONNECT,
@@ -60,10 +61,71 @@ struct narf52_gpio narf_led_4 = {
     .sense = NARF_GPIO_PIN_NOSENSE,
 };
 
-struct driver led_4 = {
+const struct driver led_4 = {
     .name = "LED_4",
     .fp = &gpio_fp,
     .dev = (void *)&narf_led_4,
 };
 
+// BUTTONs
+const struct narf52_gpio narf_button_1 = {
+    .pin_number = 13,
+    .dir = NARF_GPIO_DIR_IN,
+    .input = NARF_GPIO_PIN_INPUT_CONNECT,
+    .pull = NARF_GPIO_PIN_PULLUP,
+    .drive = NARF_GPIO_PIN_S0S1,
+    .sense = NARF_GPIO_PIN_NOSENSE,
+};
+
+const struct driver button_1 = {
+    .name = "BUTTON_1",
+    .fp = &gpio_fp,
+    .dev = (void *)&narf_button_1,
+};
+
+const struct narf52_gpio narf_button_2 = {
+    .pin_number = 14,
+    .dir = NARF_GPIO_DIR_IN,
+    .input = NARF_GPIO_PIN_INPUT_CONNECT,
+    .pull = NARF_GPIO_PIN_PULLUP,
+    .drive = NARF_GPIO_PIN_S0S1,
+    .sense = NARF_GPIO_PIN_NOSENSE,
+};
+
+const struct driver button_2 = {
+    .name = "BUTTON_2",
+    .fp = &gpio_fp,
+    .dev = (void *)&narf_button_2,
+};
+
+const struct narf52_gpio narf_button_3 = {
+    .pin_number = 15,
+    .dir = NARF_GPIO_DIR_IN,
+    .input = NARF_GPIO_PIN_INPUT_CONNECT,
+    .pull = NARF_GPIO_PIN_PULLUP,
+    .drive = NARF_GPIO_PIN_S0S1,
+    .sense = NARF_GPIO_PIN_NOSENSE,
+};
+
+const struct driver button_3 = {
+    .name = "BUTTON_3",
+    .fp = &gpio_fp,
+    .dev = (void *)&narf_button_3,
+};
+
+const struct narf52_gpio narf_button_4 = {
+    .pin_number = 16,
+    .dir = NARF_GPIO_DIR_IN,
+    .input = NARF_GPIO_PIN_INPUT_CONNECT,
+    .pull = NARF_GPIO_PIN_PULLUP,
+    .drive = NARF_GPIO_PIN_S0S1,
+    .sense = NARF_GPIO_PIN_NOSENSE,
+};
+
+const struct driver button_4 = {
+    .name = "BUTTON_4",
+    .fp = &gpio_fp,
+    .dev = (void *)&narf_button_4,
+};
+
 #endif
diff --git a/src/main.c b/src/main.c
index 0801464..e3b73d8 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,10 +1,7 @@
 #include <stdbool.h>
 #include <stdint.h>
-#include "nrf_delay.h"
-#include "boards.h"
-
-#include "platform/narf52/narf52_dk.h"
 
+#include "board.h"
 #include "driver.h"
 
 int main(void)
@@ -15,14 +12,23 @@ int main(void)
     drv_open(&led_3);
     drv_open(&led_4);
 
+    drv_open(&button_1);
+    drv_open(&button_2);
+    drv_open(&button_3);
+    drv_open(&button_4);
+
     while(true) {
-        for(uint32_t i = 0; i < UINT32_MAX; i++) {
-            char x = 0x30 | (char)(1 & i);
-            drv_write(&led_1, &x, 1);
-            drv_write(&led_2, &x, 1);
-            drv_write(&led_3, &x, 1);
-            drv_write(&led_4, &x, 1);
-            nrf_delay_ms(500);
-        }
+        char x;
+        drv_read(&button_1, &x, 1);
+        drv_write(&led_1, &x, 1);
+
+        drv_read(&button_2, &x, 1);
+        drv_write(&led_2, &x, 1);
+
+        drv_read(&button_3, &x, 1);
+        drv_write(&led_3, &x, 1);
+
+        drv_read(&button_4, &x, 1);
+        drv_write(&led_4, &x, 1);
     }
 }