diff --git a/driver/Makefile b/driver/Makefile
index 765bb8b..3b2b127 100644
--- a/driver/Makefile
+++ b/driver/Makefile
@@ -1,31 +1,31 @@
 NAME = counter
+OBJS = init.o leds.o ls7366r.o trigger.o io.o
+KDIR := /lib/modules/$(shell uname -r)/build
+DTC_FLAGS := -@ -I dts -O dtb
+
 obj-m += $(NAME).o
-$(NAME)-objs := init.o leds.o ls7366r.o trigger.o
+$(NAME)-objs := $(OBJS)
 
 all: $(NAME).ko $(NAME).dtbo
 	echo Builded Device Tree Overlay and kernel module
 
-$(NAME).ko: init.c leds.c ls7366r.c trigger.c
-	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+$(NAME).ko:
+	make -C $(KDIR) M=$(PWD) modules
 
 $(NAME).dtbo: $(NAME).dts
-	dtc -@ -I dts -O dtb -o $@ $<
+	dtc $(DTC_FLAGS) -o $@ $<
 
 clean:
-	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
+	make -C $(KDIR) M=$(PWD) clean
 	rm -rf $(NAME).dtbo
 	
 load:
-	sudo dtoverlay -d . $(NAME).dtbo
-	@echo "Overlay loaded"
-	sudo insmod ./$(NAME).ko
-	@echo "LKM loaded"
+	sudo dtoverlay -d . $(NAME).dtbo && echo "Overlay loaded"
+	sudo insmod ./$(NAME).ko && echo "LKM loaded"
 
 unload:
-	sudo rmmod ./$(NAME).ko
-	@echo "LKM unloaded"
-	sudo dtoverlay -R $(NAME)
-	@echo "Overlay unloaded"
+	sudo rmmod ./$(NAME).ko && echo "LKM unloaded"
+	sudo dtoverlay -R $(NAME) && echo "Overlay unloaded"
 
 list: 
 	sudo dtoverlay -l
diff --git a/driver/counter_io_calls.h b/driver/counter_io_calls.h
new file mode 100644
index 0000000..9cc7708
--- /dev/null
+++ b/driver/counter_io_calls.h
@@ -0,0 +1,19 @@
+#ifndef _COUNTER_IO_CALLS_H_
+#define _COUNTER_IO_CALLS_H_
+
+#ifndef __KERNEL__
+#include <stdint.h>
+#define u64 uint64_t
+#define u32 uint32_t
+#endif
+
+struct observation {
+  u64 ts_sec;
+  u64 ts_nsec;
+  u32 value;
+};
+
+
+
+
+#endif /* _COUNTER_IO_CALLS_H_ */
diff --git a/driver/init.c b/driver/init.c
index be03f7b..923b69a 100644
--- a/driver/init.c
+++ b/driver/init.c
@@ -6,6 +6,8 @@
 #include "ls7366r.h"
 #include "trigger.h"
 #include "leds.h"
+#include "io.h"
+
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Wolfgang Hottgenroth");
@@ -15,6 +17,12 @@ MODULE_DESCRIPTION("Driver for the MainsCnt measurement hat");
 
 /* module loading and unloading */
 static int __init my_init(void) {
+  printk("counter - Loading IO subsystem...\n");
+  if (io_init()) {
+    printk("counter - Error! Could not load IO subsystem\n");
+    return -1;
+  }
+        
   printk("counter - Loading the leds driver...\n");
   if(platform_driver_register(&leds_driver)) {
     printk("counter - Error! Could not load leds driver\n");
@@ -45,6 +53,9 @@ static void __exit my_exit(void) {
 
   printk("counter - Unloading the interrupt driver...\n");
   platform_driver_unregister(&interrupt_driver);
+
+  printk("counter - Unloading IO subsystem...\n");
+  io_exit();
 }
 
 module_init(my_init);
diff --git a/driver/io.c b/driver/io.c
new file mode 100644
index 0000000..0b3ea90
--- /dev/null
+++ b/driver/io.c
@@ -0,0 +1,12 @@
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include "io.h"
+
+int io_init(void) {
+  return 0;
+}
+
+void io_exit(void) {
+}
+
diff --git a/driver/io.h b/driver/io.h
new file mode 100644
index 0000000..97da6bf
--- /dev/null
+++ b/driver/io.h
@@ -0,0 +1,8 @@
+#ifndef _IO_H_
+#define _IO_H_
+
+
+int io_init(void);
+void io_exit(void);
+
+#endif /* _IO_H_ */
diff --git a/driver/leds.c b/driver/leds.c
index 17bfe43..9428e8a 100644
--- a/driver/leds.c
+++ b/driver/leds.c
@@ -6,6 +6,8 @@
 #include <linux/of_device.h>
 #include <linux/gpio/consumer.h>
 
+#include "leds.h"
+
 
 /* leds stuff */
 static int dt_leds_probe(struct platform_device *pdev);
@@ -72,3 +74,26 @@ static void dt_leds_remove(struct platform_device *pdev) {
   gpiod_put(red_led);
   gpiod_put(blue_led);
 }
+
+void led_ctrl(enum led_color_e color, enum led_state_e state) {
+  struct gpio_desc *led;
+  switch (color) {
+    case e_RED:
+      led = red_led;
+      break;
+    case e_BLUE:
+      led = blue_led;
+      break;
+  }
+  int st;
+  switch (state) {
+    case e_ON:
+      st = 1;
+      break;
+    case e_OFF:
+      st = 0;
+      break;
+  }
+  gpiod_set_value(led, st);
+}
+
diff --git a/driver/leds.h b/driver/leds.h
index 56f0af9..c3dc3db 100644
--- a/driver/leds.h
+++ b/driver/leds.h
@@ -5,4 +5,9 @@
 
 extern struct platform_driver leds_driver;
 
+enum led_color_e { e_RED, e_BLUE };
+enum led_state_e { e_ON, e_OFF };
+
+void led_ctrl(enum led_color_e color, enum led_state_e state);
+
 #endif /* _LEDS_H_ */
diff --git a/driver/trigger.c b/driver/trigger.c
index a9c82d4..092fd00 100644
--- a/driver/trigger.c
+++ b/driver/trigger.c
@@ -12,6 +12,7 @@
 #include <linux/timekeeping.h>
 
 #include "ls7366r.h"
+#include "leds.h"
 
 
 
@@ -65,12 +66,9 @@ static void counter_worker(struct work_struct *work) {
 
   if (data->last_value) {
     u32 period = counter_value - data->last_value;
-    struct timespec64 duration = timespec64_sub(data->current_timestamp, data->last_timestamp);
-    printk("counter %lld.%09lu %lld.%09lu %u\n", 
+    printk("counter %lld.%09lu %u\n", 
         (s64)((data->current_timestamp).tv_sec), 
         ((data->current_timestamp).tv_nsec), 
-        (s64)duration.tv_sec,
-        duration.tv_nsec,
         period);