diff --git a/lambda-test/Makefile b/lambda-test/Makefile
index f319fa6..6a08fcb 100644
--- a/lambda-test/Makefile
+++ b/lambda-test/Makefile
@@ -19,7 +19,7 @@
 ## Here you can link to one more directory (and multiple .c files)
 EXTRA_SOURCE_DIR = ../lambda/
 EXTRA_SOURCE_FILES = USART.c interrupts.c adc.c sensors.c integers.c \
-lcdroutines.c display.c
+lcdroutines.c display.c alert.c command.c
 
 ##########------------------------------------------------------##########
 ##########                 Programmer Defaults                  ##########
diff --git a/lambda-test/lambda-test.c b/lambda-test/lambda-test.c
index 8aa962f..5b435d7 100644
--- a/lambda-test/lambda-test.c
+++ b/lambda-test/lambda-test.c
@@ -304,7 +304,7 @@
 
 // TODO assertions
 bool testCycle(void) {
-	cycle();
+	cycleDisplay();
 
 	return true;
 }
@@ -318,7 +318,7 @@
 // TODO assertions
 bool testUpdate(void) {
 	measurement meas = {0, 0, 0, 0, 0, 0};
-	update(meas);
+	updateMeas(meas);
 
 	return true;
 }
@@ -326,7 +326,7 @@
 // TODO test display() with no display connected?
 bool testDisplay(void) {
 	measurement meas = {0, 0, 0, 0, 0, 0};
-	display(meas, "  ");
+	displayMeas(meas, "  ");
 
 	return true;
 }
diff --git a/lambda/Makefile b/lambda/Makefile
index 6d6b6b9..85e8557 100644
--- a/lambda/Makefile
+++ b/lambda/Makefile
@@ -9,13 +9,15 @@
 BAUD = 9600
 ## Also try BAUD = 19200 or 38400 if you're feeling lucky.
 
+SIMULATION = 1
+
 ## This is where your main() routine lives 
 MAIN = lambda.c
 
 ## If you've split your program into multiple .c / .h files, 
 ## include the additional source (in same directory) here 
 LOCAL_SOURCE = USART.c interrupts.c adc.c sensors.c integers.c lcdroutines.c \
-display.c alert.c
+display.c alert.c command.c
 
 ## Here you can link to one more directory (and multiple .c files)
 EXTRA_SOURCE_DIR = 
diff --git a/lambda/alert.c b/lambda/alert.c
index 3388603..25b31f4 100644
--- a/lambda/alert.c
+++ b/lambda/alert.c
@@ -10,25 +10,28 @@
 #include <avr/io.h>
 #include "USART.h"
 #include "alert.h"
+#include "sensors.h"
+#include "display.h"
 
 uint8_t oscCount = 0;
 uint8_t beepCount = 0;
-uint8_t beepLength = 0;
+uint16_t beepLength = 0;
+bool alertActive = false;
 
-void oscillate(void) {
+void oscillateBeep(void) {
 	if (beepCount == 0) {
 		return;
 	}
 	if (oscCount == 0) {
 		// turn beep on
-		DDRB |= (1 << PB1);
+		TCCR1A |= (1 << COM1A0);
 	}
 	if (oscCount == beepLength) {
 		// turn beep off
-		DDRB &= ~(1 << PB1);
+		TCCR1A &= ~(1 << COM1A0);
 		beepCount--;
 		if (beepCount == 0) {
-			// clear alert
+			alertActive = false;
 		}
 	}
 	oscCount == beepLength * 2 ? oscCount = 0 : oscCount++;
@@ -41,9 +44,18 @@
 }
 
 void alert(uint8_t beeps, uint8_t length, char* line0, char* line1) {
+	alertActive = true;
 	oscCount = 0;
 	beepCount = beeps;
 	beepLength = length;
-	// set alert
-	// set display text
+	displayText(line0, line1);
+}
+
+void cancelAlert(void) {
+	TCCR1A &= ~(1 << COM1A0);
+	alertActive = false;
+}
+
+bool isAlertActive(void) {
+	return alertActive;
 }
diff --git a/lambda/alert.h b/lambda/alert.h
index bfae948..85eec2b 100644
--- a/lambda/alert.h
+++ b/lambda/alert.h
@@ -8,10 +8,14 @@
 #ifndef ALERT_H_
 #define ALERT_H_
 
-void oscillate(void);
+void oscillateBeep(void);
 
 void beep(uint8_t beeps, uint8_t length);
 
 void alert(uint8_t beeps, uint8_t length, char* line0, char* line1);
 
+void cancelAlert(void);
+
+bool isAlertActive(void);
+
 #endif /* ALERT_H_ */
diff --git a/lambda/command.c b/lambda/command.c
new file mode 100644
index 0000000..f617d36
--- /dev/null
+++ b/lambda/command.c
@@ -0,0 +1,50 @@
+/*
+ * command.c
+ *
+ *  Created on: 02.05.2015
+ *      Author: dode@luniks.net
+ */
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <avr/interrupt.h>
+#include "sensors.h"
+#include "display.h"
+#include "alert.h"
+#include "command.h"
+
+bool simulation = false;
+
+void command(char* data) {
+	char* fields[8];
+	char* token = strtok(data, " ");
+	uint8_t index = 0;
+	while (token != NULL) {
+		fields[index++] = token;
+		token = strtok(NULL, " ");
+	}
+	if (strcmp(fields[0], "sien") == 0) {
+		simulation = true;
+		beep(1, 2);
+	}
+	else if (strcmp(fields[0], "sidi") == 0) {
+		simulation = false;
+		beep(1, 2);
+	}
+	else if (strcmp(fields[0], "menu") == 0) {
+		cycleDisplay();
+		// updateMeas(meas);
+	}
+	else if (strcmp(fields[0], "tsal") == 0) {
+		alert(3, 20, "Beep Beep Beep!", fields[1]);
+	}
+	else if (simulation) {
+		measurement meas = readMeas(fields);
+		updateMeas(meas);
+	}
+}
+
+bool isSimulation(void) {
+	return simulation;
+}
diff --git a/lambda/command.h b/lambda/command.h
new file mode 100644
index 0000000..71e0546
--- /dev/null
+++ b/lambda/command.h
@@ -0,0 +1,15 @@
+/*
+ * command.h
+ *
+ *  Created on: 02.05.2015
+ *      Author: dode@luniks.net
+ */
+
+#ifndef COMMAND_H_
+#define COMMAND_H_
+
+void command(char* data);
+
+bool isSimulation(void);
+
+#endif /* COMMAND_H_ */
diff --git a/lambda/display.c b/lambda/display.c
index cdbfa3c..0b3d7eb 100644
--- a/lambda/display.c
+++ b/lambda/display.c
@@ -15,6 +15,7 @@
 #include "integers.h"
 #include "sensors.h"
 #include "display.h"
+#include "alert.h"
 
 #define MAX(x, y) (((x) > (y)) ? (x) : (y))
 #define MIN(x, y) (((x) < (y)) ? (x) : (y))
@@ -25,17 +26,26 @@
 
 uint8_t position = MENU_OFF;
 
-measurement measMin = {0, 20, 0, 20, 0, 2000};
-measurement measMax = {0, 0, 0, 0, 0, 0};
+measurement measMin = {0, 20, 0, 20, 0, 1000};
+measurement measMax = {0, 0, 0, 0, 0, 2000};
 
-void cycle(void) {
+void cycleDisplay(void) {
+	if (isAlertActive()) {
+		// button pressed during alert
+		cancelAlert();
+		return;
+	}
+	beep(1, 2);
 	position++;
 	if (position > MENU_MAX_VALUES) {
 		position = MENU_OFF;
 	}
 }
 
-void update(measurement meas) {
+void updateMeas(measurement meas) {
+	if (isAlertActive()) {
+		return;
+	}
 	measMin.tempI = MIN(measMin.tempI, meas.tempI);
 	measMin.tempO = MIN(measMin.tempO, meas.tempO);
 	measMin.lambda = MAX(measMin.lambda, meas.lambda);
@@ -45,15 +55,15 @@
 	measMax.lambda = MIN(measMax.lambda, meas.lambda);
 
 	if (position == MENU_MIN_VALUES) {
-		display(measMin, "|<");
+		displayMeas(measMin, "|<");
 	} else if (position == MENU_MAX_VALUES) {
-		display(measMax, ">|");
+		displayMeas(measMax, ">|");
 	} else {
-		display(meas, "  ");
+		displayMeas(meas, "  ");
 	}
 }
 
-void print(measurement meas) {
+void printMeas(measurement meas) {
 	char log[64];
 	snprintf(log, sizeof(log),
 			"Ti %3d C %4u - To %3d C %4u - L %4u %4u\r\n",
@@ -62,7 +72,7 @@
 	printString(log);
 }
 
-void display(measurement meas, char* hint) {
+void displayMeas(measurement meas, char* hint) {
 	uint16_t lambdax100 = divRoundNearest(meas.lambda, 10);
 	div_t lambdaT = div(lambdax100, 100);
 
@@ -76,3 +86,11 @@
 	lcd_setcursor(0, 2);
 	lcd_string(line1);
 }
+
+void displayText(char* line0, char* line1) {
+	lcd_clear();
+	lcd_setcursor(0, 1);
+	lcd_string(line0);
+	lcd_setcursor(0, 2);
+	lcd_string(line1);
+}
diff --git a/lambda/display.h b/lambda/display.h
index 8dcc686..de2bb4c 100644
--- a/lambda/display.h
+++ b/lambda/display.h
@@ -11,22 +11,27 @@
 /**
  * Cycles through the "menu" (display options).
  */
-void cycle(void);
+void cycleDisplay(void);
 
 /**
  * Updates the measurements, tracks min and max values since last start/reset
  * and displays the selected measurement values.
  */
-void update(measurement);
+void updateMeas(measurement);
 
 /**
  * Formats the given measurement values and prints them via USART.
  */
-void print(measurement);
+void printMeas(measurement);
 
 /**
  * Formats the given measurement values and displays them on an 16x2 LCD.
  */
-void display(measurement, char*);
+void displayMeas(measurement, char*);
+
+/**
+ * Displays the given two lines of text.
+ */
+void displayText(char*, char*);
 
 #endif /* DISPLAY_H_ */
diff --git a/lambda/interrupts.c b/lambda/interrupts.c
index f2044d5..76db62d 100644
--- a/lambda/interrupts.c
+++ b/lambda/interrupts.c
@@ -13,6 +13,9 @@
 	// pull-up resistor for the mouton
 	// INT0 and INT1 are assigned to the LCD, a bit of a shame
 	PORTB |= (1 << PB0);
+
+	// enable beep output pin
+	DDRB |= (1 << PB1);
 }
 
 void setupSleepMode(void) {
@@ -26,6 +29,11 @@
 	// enable timer 0 overflow interrupt
 	TIMSK0 |= (1 << TOIE0);
 
+	// enable RC complete interrupt 0
+	UCSR0B |= (1 << RXCIE0);
+	// enable data register empty interrupt 0
+	// UCSR0B |= (1 << UDRIE0);
+
 	// enable global interrupts
 	sei();
 }
@@ -36,11 +44,13 @@
 	TCCR0B |= (1 << CS01) | (1 << CS00);
 
 	// toggle pin PB1 on compare match
-	TCCR1A |= (1 << COM1A0);
+	// TCCR1A |= (1 << COM1A0);
 	// CTC mode, TOP OCR1A
 	TCCR1B |= (1 << WGM12);
 	// timer clock prescaler/8
 	TCCR1B |= (1 << CS11);
-	// toggles PB1 at 3.9 kHz generating a 1.95 kHz beep
+	// toggles PB1 at 7.8 kHz generating a 3.9 kHz beep
+	// OCR1A = 16;
+	// less noisy
 	OCR1A = 32;
 }
diff --git a/lambda/lambda.c b/lambda/lambda.c
index 87258d6..606df42 100644
--- a/lambda/lambda.c
+++ b/lambda/lambda.c
@@ -19,6 +19,7 @@
 
 #include <stdio.h>
 #include <stdbool.h>
+#include <string.h>
 #include <util/delay.h>
 #include <avr/io.h>
 #include <avr/interrupt.h>
@@ -30,25 +31,43 @@
 #include "integers.h"
 #include "display.h"
 #include "alert.h"
+#include "command.h"
 
 volatile bool buttonPressed = false;
+volatile bool usartReceived = false;
 volatile uint8_t intCount = 0;
+volatile uint8_t dataCount = 0;
+
+char usartData[64];
 
 /**
  * Called every 16 ms.
  */
 ISR(TIMER0_OVF_vect) {
 	intCount++;
-	oscillate();
+	oscillateBeep();
 	if (bit_is_clear(PINB, PB0) && ! buttonPressed) {
 		buttonPressed = true;
-		cycle();
-		beep(3, 3);
+		cycleDisplay();
 	} else if (bit_is_set(PINB, PB0)) {
 		buttonPressed = false;
 	}
 }
 
+ISR(USART_RX_vect) {
+	if (bit_is_set(UCSR0A, RXC0) && ! usartReceived) {
+		char data = UDR0;
+		loop_until_bit_is_set(UCSR0A, UDRE0);
+		UDR0 = data;
+		if (dataCount < sizeof(usartData) - 1 && data != '\n' && data != '\r') {
+			usartData[dataCount++] = data;
+		} else {
+			usartData[dataCount++] = 0;
+			usartReceived = true;
+		}
+	}
+}
+
 /**
  * Does initialization and measures, displays and logs the measurements
  * infinitely.
@@ -62,19 +81,29 @@
 	initInterrupts();
 	initTimers();
 
+	alert(1, 2, "     Hello!     ", "");
+
+	measurement meas;
+	// memset(&meas, 0, sizeof(meas));
+
 	// main loop
 	while (1) {
-		measurement meas;
-		if (intCount >= 61) {
+		if (intCount >= 62 && ! isSimulation()) {
 			intCount = 0;
 			// causes a click in the beep, because of sleep mode?
 			meas = measure();
-			update(meas);
-			print(meas);
+			printMeas(meas);
+			updateMeas(meas);
 		}
 		if (buttonPressed) {
 			// update display immediately
-			update(meas);
+			updateMeas(meas);
+		}
+		if (usartReceived) {
+			command(usartData);
+			memset(usartData, 0, sizeof(usartData));
+			dataCount = 0;
+			usartReceived = false;
 		}
 	}
 
diff --git a/lambda/sensors.c b/lambda/sensors.c
index ae0038d..74e1298 100644
--- a/lambda/sensors.c
+++ b/lambda/sensors.c
@@ -11,7 +11,9 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <avr/io.h>
+#include "USART.h"
 #include "adc.h"
 #include "sensors.h"
 #include "integers.h"
@@ -92,6 +94,15 @@
 	return meas;
 }
 
+measurement readMeas(char* fields[]) {
+	measurement meas;
+	meas.tempI  = strtol(fields[0], NULL, 10);
+	meas.tempO  = strtol(fields[1], NULL, 10);
+	meas.lambda = strtol(fields[2], NULL, 10);
+
+	return meas;
+}
+
 int16_t toTempI(uint16_t mV) {
 	int temp = divRoundNearest(mV, 5);
 
diff --git a/lambda/sensors.h b/lambda/sensors.h
index fa53989..299fa44 100644
--- a/lambda/sensors.h
+++ b/lambda/sensors.h
@@ -40,11 +40,18 @@
 
 /**
  * Measures the "input" and "output" temperatures and the lambda value
- * and displays the measured values.
+ * and returns them.
  */
 measurement measure(void);
 
 /**
+ * Reads measurement data from the given array of strings, used to simulate
+ * a burnoff with data logged during real burnoffs. The voltages are not used,
+ * the space separated fields are tempI, tempO and lambda.
+ */
+measurement readMeas(char* usartData[]);
+
+/**
  * Returns the temperature for the given voltage of a type K thermocouple
  * amplified with an AD8495 (5 mV/°C). Type K thermocouple voltages are
  * about linear between 0 and 800°C.