diff --git a/firmware/slider/CMakeLists.txt b/firmware/slider/CMakeLists.txt
index c59228a..caade73 100644
--- a/firmware/slider/CMakeLists.txt
+++ b/firmware/slider/CMakeLists.txt
@@ -7,5 +7,5 @@ project(slider_firmware C)
 
 add_subdirectory(SliderCommunication)
 
-add_avr_executable(slider_firmware led.c main.c adc.c )
+add_avr_executable(slider_firmware led.c main.c adc.c button.c)
 target_link_libraries(slider_firmware DSPLAB_SliderCommunication)
diff --git a/firmware/slider/SliderCommunication b/firmware/slider/SliderCommunication
index 36d759d..3141a62 160000
--- a/firmware/slider/SliderCommunication
+++ b/firmware/slider/SliderCommunication
@@ -1 +1 @@
-Subproject commit 36d759d94c6fa9166de35624989858811a73861f
+Subproject commit 3141a62e62012dee60192e6ad1c95ee5b63fc8ce
diff --git a/firmware/slider/adc.c b/firmware/slider/adc.c
index 2d420b3..0f108dc 100644
--- a/firmware/slider/adc.c
+++ b/firmware/slider/adc.c
@@ -6,11 +6,11 @@
  */
 
 #include "adc.h"
+#include "main.h"
+
 #include <avr/io.h>
 #include <avr/interrupt.h>
 
-#include "led.h"
-
 // global adc instance
 volatile adc_t adc;
 
@@ -21,8 +21,12 @@ static inline void adc_next() {
 		if (!adc.current_channel) {
 			adc.current_sample = adc.buffer.ptr-1;
 
-			if (adc.interrupt)
-				adc.interrupt(&adc.buffer);
+			// update app state (remap channels)
+			app.state.state.slider  = adc.buffer.ptr[4];
+			app.state.state.poti[0] = adc.buffer.ptr[3];
+			app.state.state.poti[1] = adc.buffer.ptr[2];
+			app.state.state.poti[2] = adc.buffer.ptr[0];
+			app.state.state.poti[3] = adc.buffer.ptr[1];
 		}
 	} while(!(adc.channel_mask & (1<<adc.current_channel)));
 
@@ -34,10 +38,6 @@ static inline void adc_next() {
 	ADMUX = adc.current_channel;
 }
 
-void adc_on_done(adc_interrupt_t interrupt) {
-	adc.interrupt = interrupt;
-}
-
 /* adc driver */
 void adc_init(adc_buffer_t buffer, uint8_t mask) {
 	if (!mask) {
@@ -54,8 +54,6 @@ void adc_init(adc_buffer_t buffer, uint8_t mask) {
 		adc.current_channel++;
 	}
 
-	adc.interrupt = 0;
-
 	ADMUX  = 0;
 	ADCSRA = (1<<ADATE) | (1<<ADEN) ; // enable adc, maximum prescaler value
 }
diff --git a/firmware/slider/adc.h b/firmware/slider/adc.h
index 2070166..2eab70d 100644
--- a/firmware/slider/adc.h
+++ b/firmware/slider/adc.h
@@ -17,16 +17,12 @@ typedef struct {
 	uint8_t size;
 } adc_buffer_t;
 
-typedef void (*adc_interrupt_t)(volatile adc_buffer_t * buf);
-
 typedef struct adc {
 	adc_buffer_t buffer;
 
 	uint8_t current_channel;
 	adc_sample_t * current_sample;
 	uint8_t channel_mask;
-
-	adc_interrupt_t interrupt;
 } adc_t;
 
 // the adc instance
@@ -47,8 +43,6 @@ enum {
 
 void adc_init(adc_buffer_t buffer, uint8_t channel_mask);
 
-void adc_on_done(adc_interrupt_t interrupt);
-
 void adc_start();
 void adc_stop();
 
diff --git a/firmware/slider/button.c b/firmware/slider/button.c
new file mode 100644
index 0000000..e7d1d2d
--- /dev/null
+++ b/firmware/slider/button.c
@@ -0,0 +1,31 @@
+#include "button.h"
+#include "main.h"
+#include "led.h"
+
+#include <avr/interrupt.h>
+
+void button_init() 
+{
+	led_init();
+
+	// enable pullup on button pin
+	BUTTON_DDR &= ~(1<<BUTTON_PIN);
+	BUTTON_PORT |= (1<<BUTTON_PIN);
+	
+	// activate pin change interrupt
+	// PCINT9
+	PCMSK1 |= (1<<PCINT9);
+	GIMSK  |= (1<<PCIE1); // enable PCINT1
+}
+
+button_state_t button_is_pressed() 
+{
+	return (BUTTON_REG&(1<<BUTTON_PIN)) > 0;
+}
+
+ISR(PCINT1_vect) {
+	if(!(BUTTON_REG&(1<<BUTTON_PIN))) {
+		app.state.state.button = !app.state.state.button;
+		led_toggle();
+	}
+}
diff --git a/firmware/slider/button.h b/firmware/slider/button.h
new file mode 100644
index 0000000..55348ad
--- /dev/null
+++ b/firmware/slider/button.h
@@ -0,0 +1,22 @@
+
+#ifndef BUTTON_H_
+#define BUTTON_H_
+
+#include <avr/io.h>
+
+/* button driver */
+#define BUTTON_DDR  DDRB
+#define BUTTON_PORT PORTB
+#define BUTTON_REG  PINB
+#define BUTTON_PIN  1
+
+typedef enum {
+	BUTTON_RELEASED = 0,
+	BUTTON_PRESSED = 1
+} button_state_t;
+
+void button_init();
+button_state_t button_is_pressed();
+
+
+#endif // BUTTON_H_
\ No newline at end of file
diff --git a/firmware/slider/main.c b/firmware/slider/main.c
index d91a3da..ef07a18 100644
--- a/firmware/slider/main.c
+++ b/firmware/slider/main.c
@@ -2,36 +2,8 @@
 #include <avr/interrupt.h>
 #include "adc.h"
 #include "led.h"
-
-
-/* button driver */
-// TODO: make interrupt driven
-#define BUTTON_DDR DDRB
-#define BUTTON_PORT PORTB
-#define BUTTON_REG PINB
-#define BUTTON_PIN 1
-
-enum {
-	BUTTON_RELEASED,
-	BUTTON_PRESSED
-} button_state;
-
-void button_init() {
-	led_init();
-
-	BUTTON_DDR &= ~(1<<BUTTON_PIN);
-	BUTTON_PORT |= (1<<BUTTON_PIN);
-	// activate pin change interrupt
-	// PCINT9
-	PCMSK1 |= (1<<PCINT9);
-	GIMSK  |= (1<<PCIE1); // enable PCINT1
-}
-
-
-
-int button_is_pressed() {
-	return BUTTON_REG&(1<<BUTTON_PIN);
-}
+#include "button.h"
+#include "main.h"
 
 /* Communication driver */
 #define SLAVE_ENABLE_DDR DDRA
@@ -40,8 +12,13 @@ int button_is_pressed() {
 
 #include <interface.h>
 
+typedef struct {
+	iface_t iface;
+} comm_t;
+
+comm_t  comm;
 void comm_write(iface_t * iface, byte_t byte) {
-	// disable interrupt
+	// disable interrupt (temporarily)
 	uint8_t temp = USICR;
 	USICR &= ~(1<<USIOIE);
 
@@ -55,18 +32,18 @@ void comm_write(iface_t * iface, byte_t byte) {
 	USICR = temp;	
 }
 
-iface_t comm_iface;
-
 void comm_init() {
 	// TODO: setup pins
 	// TODO: setup USART in synchronous mode
 	USICR = (1<<USIWM0)|(1<<USICS1);
 
-	comm_iface.write = comm_write;
+	// init interface
+	comm.iface.write = comm_write;
 }
 
 void comm_start() {
-	if (!comm_iface.on_read)
+	// don't start without interrupt handler
+	if (!comm.iface.on_read)
 		return;
 
 	// TODO: activate USART 
@@ -74,20 +51,10 @@ void comm_start() {
 }
 
 ISR(USI_OVF_vect) {
-	byte_t byte = USIBR;
-	
-	// only operate when enabled
-	if (SLAVE_ENABLE_REG & (1<<SLAVE_ENABLE_PIN)) {
-		return;
-	}
-	
-	if (comm_iface.on_read) {
-		comm_iface.on_read(&comm_iface, byte);
-	}
+	// call interrupt handler
+	comm.iface.on_read(&comm.iface, USIBR, comm.iface.callback_data);
 }
 
-#include <communication.h>
-
 void on_read(iface_t * sender, byte_t b) {
 	if (!IS_EOM(b)) {
 		sender->write(sender, b);
@@ -98,56 +65,55 @@ void on_read(iface_t * sender, byte_t b) {
 	sender->write(sender, b&0x7F);
 }
 
-struct {
-	volatile message_t buffer;
-	adc_sample_t adc_buffer[5];
-} app = {};
+#include "main.h"
 
+// the public instance of the app buffer
+struct app app = {};
 
-ISR(PCINT1_vect) {
-	if(BUTTON_REG&(1<<BUTTON_PIN)) {
-		app.buffer.button = !app.buffer.button;
-		led_toggle();
-	}
-}
-
-/* main application code */
+// initalizes the application modules
 void init() {
+	// init button module (making the button light up on press)
+	// module also updates app.buffer.button for us
 	button_init();
 
+	// init adc module
+	// will sample 0x8F (CHANNEL 8 and 0-3) 
+	// this module also updates app.buffer.poti and slider for us
 	adc_init((adc_buffer_t){
 		.ptr  = app.adc_buffer,
 		.size = 5,
 	}, 0x8F);
 
-	// activate interrupts
+	// init communication module
+	comm_init();
+	
+	// bind state encoder to communication module
+	slave_init(&app.state, &comm.iface);
+	
+	// start all modules
+	adc_start();
+	comm_start();
+	
+	// activate interrupts (effectivly starting the application)
 	sei();
 }
 
+
+// little debug helper function
+// FIXME: remove when not needed
 void delay(uint16_t d) {
 	while(d--) {
 		__asm("nop");
 	}
 }
 
-void adc_int(volatile adc_buffer_t * buf)
-{
-	app.buffer.slider  = buf->ptr[4];
-
-	app.buffer.poti[0] = buf->ptr[3];
-	app.buffer.poti[1] = buf->ptr[2];
-	app.buffer.poti[2] = buf->ptr[0];
-	app.buffer.poti[3] = buf->ptr[1];
-}
-
 int main() {
 	init();
-	adc_on_done(adc_int);
 
-	// start relevant perephials
+	// start relevant periphials
 	adc_start();
 
 	while(1) {
-		delay(app.buffer.poti[0]>>4);
+		// nothing to do here, the application is interrupt-driven
 	}
 }
diff --git a/firmware/slider/main.h b/firmware/slider/main.h
new file mode 100644
index 0000000..143a2a5
--- /dev/null
+++ b/firmware/slider/main.h
@@ -0,0 +1,16 @@
+
+#ifndef APP_H__
+#define APP_H__
+
+#include <communication.h>
+#include "adc.h"
+#include <slave/slave.h>
+
+struct app {
+	slave_t state;
+	adc_sample_t adc_buffer[5];
+};
+
+extern struct app app;
+
+#endif
\ No newline at end of file