diff --git a/drivers/dac101c085.c b/drivers/dac101c085.c
index 6c5662b..4493620 100644
--- a/drivers/dac101c085.c
+++ b/drivers/dac101c085.c
@@ -20,20 +20,18 @@ void init(void)
 void setDAC(uint16_t new_value)
 {
 	uint8_t ub = (new_value >> 6) & 0x0F;
-	//uint8_t ub = 0x10;
 	uint8_t lb = (new_value << 2) & 0xFF;
 	init();
-	osPrintf("Upper %d\n", ub);
-	osPrintf("Lower %d\n", lb);
 	i2cStartTransmission(I2Cx_DAC, I2C_Direction_Transmitter, DAC_ADDR);
-	i2cWrite(I2Cx_DAC, &ub);
-	i2cWrite(I2Cx_DAC, &lb);
+	i2cWrite(I2Cx_DAC, &ub, 1, STANDARD_I2C_TIMEOUT);
+	i2cWrite(I2Cx_DAC, &lb, 1, STANDARD_I2C_TIMEOUT);
 	i2cEndTransmission(I2Cx_DAC);
 }
 
 uint16_t readDAC(void)
 {
 	uint16_t dac_val = 1;
+	init();
 	i2cStartTransmission(I2Cx_DAC, I2C_Direction_Receiver, DAC_ADDR);
 	i2cAckOn(I2Cx_DAC);
 	dac_val = i2cRead(I2Cx_DAC);
diff --git a/main.c b/main.c
index 9cd602f..97d245a 100644
--- a/main.c
+++ b/main.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include "platform/porting.h"
 #include "drivers/dac101c085.h"
+#include "platform/ext_interrupt.h"
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-parameter"
@@ -39,7 +40,8 @@ int main(int argc, char* argv[])
 	RCC_GetClocksFreq (&RCC_Clocks);
 	osPrintf("System Core Clock: %d\n\r", SystemCoreClock);
 	osPrintf("HCLK: %d\n\r", RCC_Clocks.HCLK_Frequency);
-	osTaskCreate(*task3, "task 3", args, 1, NULL);
+	initExtInt();
+	//osTaskCreate(*task3, "task 3", args, 1, NULL);
 	while (1);
 	// Infinite loop, never return.
 }
diff --git a/platform/ext_interrupt.c b/platform/ext_interrupt.c
new file mode 100644
index 0000000..6878ffd
--- /dev/null
+++ b/platform/ext_interrupt.c
@@ -0,0 +1,48 @@
+/*
+ * ext_interrupt.c
+ *
+ *  Created on: 3 Sep 2019
+ *      Author: maximilian
+ */
+
+#include "ext_interrupt.h"
+
+void initExtInt(void)
+{
+	// Initialization structs
+	GPIO_InitTypeDef exti_gpio;
+
+	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
+	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
+
+    //Additionally we need to initialize corresponding GPIOs
+    exti_gpio.GPIO_Pin = GPIO_Pin_8;
+    exti_gpio.GPIO_Mode = GPIO_Mode_IN_FLOATING;
+    exti_gpio.GPIO_Speed = GPIO_Speed_50MHz;
+    GPIO_Init(GPIOC, &exti_gpio);
+
+	GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource8);
+
+	EXTI_InitTypeDef EXTI_InitStructure;
+	EXTI_InitStructure.EXTI_Line = EXTI_Line8;
+	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
+	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
+	EXTI_InitStructure.EXTI_LineCmd = ENABLE;
+	EXTI_Init(&EXTI_InitStructure);
+
+	NVIC_InitTypeDef NVIC_InitStructure;
+	NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn; //Enable keypad external interrupt channel
+	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F; //Priority 2,
+	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F; //Sub priority 2
+	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //Enable external interrupt channel
+	NVIC_Init(&NVIC_InitStructure);
+	osPrintf("Ext. int initialized.");
+}
+
+void EXTI9_5_IRQHandler(void)
+{
+	osPrintf("Got interrupt.");
+	if(EXTI_GetITStatus(EXTI_Line8) != RESET) {
+		EXTI_ClearITPendingBit(EXTI_Line0);
+	}
+}
diff --git a/platform/ext_interrupt.h b/platform/ext_interrupt.h
new file mode 100644
index 0000000..92ceabf
--- /dev/null
+++ b/platform/ext_interrupt.h
@@ -0,0 +1,16 @@
+/*
+ * ext_interrupt.h
+ *
+ *  Created on: 3 Sep 2019
+ *      Author: maximilian
+ */
+
+#ifndef PLATFORM_EXT_INTERRUPT_H_
+#define PLATFORM_EXT_INTERRUPT_H_
+
+#include "stm32f10x.h"
+#include <stdlib.h>
+
+void initExtInt(void);
+
+#endif /* PLATFORM_EXT_INTERRUPT_H_ */
diff --git a/platform/i2c.h b/platform/i2c.h
index 55b9923..d71da17 100644
--- a/platform/i2c.h
+++ b/platform/i2c.h
@@ -11,10 +11,12 @@
 #include "stm32f10x.h"
 #include <stdlib.h>
 
+#define STANDARD_I2C_TIMEOUT 1000
+
 void i2cInit(I2C_TypeDef* I2Cx);
 void i2c1Init(void);
 void i2cStartTransmission(I2C_TypeDef* I2Cx, uint8_t dir,  uint8_t slave_addr);
-void i2cWrite(I2C_TypeDef* I2Cx, uint8_t* data);
+void i2cWrite(I2C_TypeDef* I2Cx, uint8_t* data, uint16_t len, uint32_t timeout);
 uint8_t i2cRead(I2C_TypeDef* I2Cx);
 void i2cEndTransmission(I2C_TypeDef* I2Cx);