diff --git a/firmware/slider/CMakeLists.txt b/firmware/slider/CMakeLists.txt
index caade73..050e91c 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 button.c)
+add_avr_executable(slider_firmware led.c main.c adc.c button.c comm.c)
 target_link_libraries(slider_firmware DSPLAB_SliderCommunication)
diff --git a/firmware/slider/adc.c b/firmware/slider/adc.c
index 439796a..2b22eec 100644
--- a/firmware/slider/adc.c
+++ b/firmware/slider/adc.c
@@ -16,21 +16,9 @@ adc_t adc;
 
 /* adc driver */
 void adc_init(uint8_t * channels) {
-	adc.current_channel = 0;
-	adc.channel_map = channels;
+//	adc.current_channel = 0;
+//	adc.channel_map = channels;
 
 	ADMUX = channels[0];
-	ADCSRA = (1<<ADATE) | (1<<ADEN) | 7; // enable adc, maximum prescaler value
+	ADCSRA = /*(1<<ADATE) | */ (1<<ADEN); // enable adc, maximum prescaler value
 }
-
-ISR(ADC_vect) {
-	adc.buffer[adc.current_channel] = ADC;
-	adc.current_channel++;
-
-	if (adc.current_channel == ADC_BUFFER_SIZE) {
-		adc.current_channel = 0;
-	}
-
-	ADMUX = adc.channel_map[adc.current_channel];
-}
-
diff --git a/firmware/slider/adc.h b/firmware/slider/adc.h
index 024fd82..8ce7973 100644
--- a/firmware/slider/adc.h
+++ b/firmware/slider/adc.h
@@ -19,10 +19,11 @@ typedef struct {
 } adc_buffer_t;
 
 typedef struct adc {
-	adc_sample_t buffer[ADC_BUFFER_SIZE];
+	//adc_sample_t buffer[ADC_BUFFER_SIZE];
 
-	volatile uint8_t current_channel;
+	/*volatile uint8_t current_channel;
 	uint8_t * channel_map;
+	*/
 } adc_t;
 
 // the adc instance
@@ -30,7 +31,9 @@ extern adc_t adc;
 
 void adc_init(uint8_t * channels);
 
-#define adc_start() ADCSRA |= (1<<ADIE) | (1<<ADSC)
-#define adc_stop()  ADCSRA &= ~(1<<ADIE)
+#define adc_start() do { ADCSRA |= (1<<ADSC); } while(0)
+#define adc_finished() (ADCSRA & (1<<ADIF))
+#define adc_set_channel(channel) do { ADMUX = channel; } while(0)
+#define adc_value() ADC
 
 #endif /* ADC_H_ */
diff --git a/firmware/slider/button.c b/firmware/slider/button.c
index e7d1d2d..6475464 100644
--- a/firmware/slider/button.c
+++ b/firmware/slider/button.c
@@ -25,7 +25,7 @@ button_state_t button_is_pressed()
 
 ISR(PCINT1_vect) {
 	if(!(BUTTON_REG&(1<<BUTTON_PIN))) {
-		app.state.state.button = !app.state.state.button;
+		app.button = !app.button;
 		led_toggle();
 	}
 }
diff --git a/firmware/slider/comm.c b/firmware/slider/comm.c
new file mode 100644
index 0000000..82fb10e
--- /dev/null
+++ b/firmware/slider/comm.c
@@ -0,0 +1,14 @@
+/*
+ * comm.c
+ *
+ *  Created on: 13.02.2019
+ *      Author: julian
+ */
+
+#include <avr/io.h>
+
+void comm_init()
+{
+	DDRA |= (1<<PA5); // setup MOSI as output
+	USICR = (1<<USIWM0)|(1<<USICS1);
+}
diff --git a/firmware/slider/comm.h b/firmware/slider/comm.h
new file mode 100644
index 0000000..1bd8202
--- /dev/null
+++ b/firmware/slider/comm.h
@@ -0,0 +1,13 @@
+/*
+ * comm.h
+ *
+ *  Created on: 13.02.2019
+ *      Author: julian
+ */
+
+#ifndef COMM_H_
+#define COMM_H_
+
+void comm_init();
+
+#endif /* COMM_H_ */
diff --git a/firmware/slider/main.c b/firmware/slider/main.c
index 1db0ecc..3315c62 100644
--- a/firmware/slider/main.c
+++ b/firmware/slider/main.c
@@ -4,6 +4,7 @@
 #include "led.h"
 #include "button.h"
 #include "main.h"
+#include "comm.h"
 
 /* Communication driver */
 #define SLAVE_ENABLE_DDR DDRA
@@ -12,16 +13,12 @@
 
 #include <interface.h>
 
-#include "main.h"
-
-void comm_init();
-
 // the public instance of the app buffer
 struct app app = {};
 
 uint8_t channel_map[ADC_BUFFER_SIZE] = {
-	0,
 	1,
+	0,
 	2,
 	3,
 	7
@@ -49,12 +46,8 @@ void init()
 	sei();
 }
 
-void comm_init()
-{
-	DDRA |= (1<<PA5); // setup MOSI as output
-	USICR = (1<<USIWM0)|(1<<USICS1);
-}
 
+// All states of the transaction state machine
 volatile enum {
 	COMM_WAIT       = 0,
 	COMM_SEND_START ,
@@ -69,25 +62,33 @@ static inline void comm_service()
 
 	if (USISR & (1<<USIOIF))
 	{
-		led_on();
 		cli();
 
 		switch(comm_state)
 		{
 		case COMM_WAIT:
+			// only trigger on start of transmission
 			if (IS_EOM(USIDR)) {
-				// pass package through
 				USIDR &= ~0x80;
 				comm_state = COMM_SEND_START;
-				adc_stop();
+
+				// sample first channel
+				adc_start();
 			}
 			break;
 		case COMM_SEND_START:
-			temp = adc.buffer[count];
+			// transmit LSByte of value
+			temp = adc_value();
+
+			// sample next channel
+			adc_set_channel(channel_map[count+1]);
+			adc_start();
+
 			USIDR = temp & 0x7F;
 			comm_state = COMM_SEND_WAIT;
 			break;
 		case COMM_SEND_WAIT:
+			// transmit MSByte
 			USIDR = (temp>>7)&0x7F;
 
 			if (++count == ADC_BUFFER_SIZE) {
@@ -97,20 +98,23 @@ static inline void comm_service()
 			}
 			break;
 		case COMM_SEND_END:
+			// cleanup the transaction
 			count = 0;
-			USIDR = app.state.state.button | 0x80;
+			// transmit the button state and end of transaction
+			USIDR = app.button | 0x80;
 		default:
 			comm_state = COMM_WAIT;
-			adc_start();
+			// reset channel of adc back to 0
+			adc_set_channel(channel_map[0]);
 			break;
 		}
 
 		USISR |= (1<<USIOIF);
 
 		sei();
-		led_off();
 	}
 }
+
 #include <util/delay.h>
 
 // little debug helper function
diff --git a/firmware/slider/main.h b/firmware/slider/main.h
index 3e8c14a..f9025aa 100644
--- a/firmware/slider/main.h
+++ b/firmware/slider/main.h
@@ -7,9 +7,9 @@
 #include <slave/slave.h>
 
 struct app {
-	slave_t state;
+	volatile uint8_t button;
 };
 
 extern struct app app;
 
-#endif
\ No newline at end of file
+#endif