diff --git a/B15F.elf b/B15F.elf
index 3007bd3..2832be0 100644
Binary files a/B15F.elf and b/B15F.elf differ
diff --git a/B15F.hex b/B15F.hex
index d80459c..94f989d 100644
--- a/B15F.hex
+++ b/B15F.hex
@@ -6,11 +6,11 @@
 :100050000C9464000C9464000C9464000C94640090
 :100060000C9464000C9464000C9464000C94640080
 :100070000C9464000C9464000C9464000C94640070
-:100080000C9464000C9464000C946400C601112468
+:100080000C9464000C9464000C946400E801112446
 :100090001FBECFEFD0E4DEBFCDBF21E0A0E0B1E0D6
-:1000A00001C01D92AA30B207E1F710E0C7E4D0E02A
-:1000B00004C02197FE010E94DF01C634D107C9F7B1
-:1000C0000E949E010C94E8010C9400001F920F9274
+:1000A00001C01D92AB30B207E1F710E0C7E4D0E029
+:1000B00004C02197FE010E940102C634D107C9F78E
+:1000C0000E94BE010C940A020C9400001F920F9231
 :1000D0000FB60F921124289A2FEF84E39CE0215051
 :1000E00080409040E1F700C0000028982FEF84E3A3
 :1000F0009CE0215080409040E1F700C00000EBCF31
@@ -49,15 +49,19 @@
 :10030000B8010024660F771F001C660F771F001CC2
 :10031000672F702D888199810E949D00602F660F44
 :10032000660F888199810E949D0067E0888199818C
-:10033000DF91CF911F910F910C949300209A2898F0
-:10034000A895789489E091E00E94810060E086E0C1
-:1003500091E00E94A8006FEF86E091E00E94C90042
-:100360006FEF83E091E00E94C900C0E0D0E0BE01E1
-:1003700080E091E00E94750182E48A95F1F700C067
-:100380002196C11584E0D80781F3F1CF89E091E08F
-:100390000E94800042E069E071E086E091E00E9406
-:1003A000A30045E069E071E083E091E00E94A300D2
-:1003B00040E069E071E080E091E00C947201EE0FA2
-:1003C000FF1F0024001C0BBE0790F691E02D09943E
-:0403D000F894FFCFCF
+:10033000DF91CF911F910F910C94930010927C004C
+:1003400087E880937A00089580917C00807E682BF6
+:1003500060937C0080917A00806480937A0083EAC5
+:1003600091E00197F1F700C0000080917A0086FDCE
+:10037000FCCF8091780090917900089581E6809378
+:100380006000209A2898A89578948AE091E00E94CD
+:10039000810060E087E091E00E94A8006FEF87E0B5
+:1003A00091E00E94C9006FEF84E091E00E94C900D3
+:1003B00080E091E00E949E0166E080E091E00E9472
+:1003C000A401BC0181E091E00E947501A895F4CFE1
+:1003D0008AE091E00E94800042E06AE071E087E0FC
+:1003E00091E00E94A30045E06AE071E084E091E0C2
+:1003F0000E94A30040E06AE071E081E091E00C948B
+:100400007201EE0FFF1F0024001C0BBE0790F69137
+:08041000E02D0994F894FFCFE0
 :00000001FF
diff --git a/Makefile b/Makefile
index 7dd3114..3389530 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ OUTPUT  = B15F.elf
 HEX		= B15F.hex
 CFLAGS  = -std=c++14 -O3 -mmcu=atmega1284 -DF_CPU=20000000 -DPIO_DISABLE_I2C
 LDFLAGS = 
-OBJECTS = main.o spi.o mcp23s17.o tlc5615.o
+OBJECTS = main.o spi.o mcp23s17.o tlc5615.o adu.o
 
 
 COMPILE = $(COMPILER_PATH) $(CFLAGS)
diff --git a/adu.cpp b/adu.cpp
new file mode 100644
index 0000000..7038168
--- /dev/null
+++ b/adu.cpp
@@ -0,0 +1,28 @@
+#include "adu.h"
+
+void ADU::init()
+{
+	// externe Referenz an AREF
+	ADMUX = 0;
+
+	// ADC aktiviert, prescaler = 128
+	ADCSRA = _BV(ADEN) | _BV(ADPS2) | _BV(ADPS1) | _BV(ADPS0);
+}
+
+uint16_t ADU::getValue(uint8_t channel)
+{
+	// lege Kanal fest
+	ADMUX = (ADMUX & 0xE0) | channel;
+
+	// starte Konvertierung
+	ADCSRA |= _BV(ADSC);
+	
+	// warte Konvertierungszeit ab
+	_delay_us(13 * 1000000 * 128 / F_CPU + 1);
+
+	// warte auf Ende
+	while(ADCSRA & _BV(ADSC));
+
+	// liefere Ergebnis
+	return ADCW;
+}
diff --git a/adu.h b/adu.h
new file mode 100644
index 0000000..ad4828e
--- /dev/null
+++ b/adu.h
@@ -0,0 +1,15 @@
+#ifndef ADC_H
+#define ADC_H
+
+#include <avr/io.h>
+#include <util/delay.h>
+#include <stdint.h>
+
+class ADU
+{
+public:
+	void init(void);
+	uint16_t getValue(uint8_t);
+};
+
+#endif // ADC_H
diff --git a/main.cpp b/main.cpp
index 5e1e204..3a60a8a 100644
--- a/main.cpp
+++ b/main.cpp
@@ -4,6 +4,7 @@
 #include <avr/wdt.h>
 #include "mcp23s17.h"
 #include "tlc5615.h"
+#include "adu.h"
 
 #define LED B0
 
@@ -12,6 +13,7 @@ SPI spi;
 MCP23S17 beba0(spi, SPIADR::BEBA0);
 MCP23S17 sw(spi, SPIADR::SWITCH);
 TLC5615 dac0(spi, SPIADR::AA0);
+ADU adu;
 
 ISR(WDT_vect)
 {
@@ -27,7 +29,7 @@ ISR(WDT_vect)
 
 int main()
 {
-	//WDTCSR = _BV(WDIE) | _BV(WDP3) | _BV(WDP0);
+	WDTCSR = _BV(WDIE) | _BV(WDP3) | _BV(WDP0);
 	dMode(LED, OUT);
 	dWrite(LED, LOW);
 	wdt_reset();
@@ -38,14 +40,13 @@ int main()
 	beba0.setDirA(0x00); // alle Ausgang
 	beba0.setDirB(0xFF); // alle Eingang
 	sw.setDirB(0xFF); // alle Eingang
+
+	adu.init();
 	
 	while(1)
 	{
-		for(uint16_t i = 0; i < 1024; i++)
-		{
-			dac0.setValue(i);
-			_delay_us(10);
-		}
+		dac0.setValue(adu.getValue(6));
+		wdt_reset();
 	}
 
 	return 0;
diff --git a/spi.h b/spi.h
index 8999756..60cb6f8 100644
--- a/spi.h
+++ b/spi.h
@@ -19,6 +19,7 @@ enum SPIADR {
 	AA1 = 1,
 	BEBA0 = 2,
 	BEBA1 = 3,
+	EXT = 4,
 	SWITCH = 5,
 	NONE = 7,
 };