diff --git a/lambda-test/lambda-test.c b/lambda-test/lambda-test.c
index 8d414f4..a64f83b 100644
--- a/lambda-test/lambda-test.c
+++ b/lambda-test/lambda-test.c
@@ -88,9 +88,9 @@
 	uint8_t prescalerBy64 = (1 << CS00) | (1 << CS01);
 	assertTrue((TCCR0B & prescalerBy64) == prescalerBy64);
 
-	// timer1 CTC mode, TOP OCR1A
+	// timer1 Clear Timer on Compare Match mode, TOP OCR1A
 	assertTrue(bit_is_set(TCCR1B, WGM12));
-	// timer clock prescaler/8
+	// timer1 clock prescaler/8
 	assertTrue(bit_is_set(TCCR1B, CS11));
 	// toggles PB1 at 7.8 kHz generating a 3.9 kHz beep
 	// assertTrue(OCR1A == 16);
@@ -216,14 +216,11 @@
 		meas = measure();
 	}
 
-	assertTrue(meas.tempIVoltage > 4900);
-	assertTrue(meas.tempOVoltage > 4900);
-	assertTrue(meas.lambdaVoltage > 4900);
-
 	// verify that temperatures and lambda are calculated correctly
-	assertTrue(meas.tempI == toTempI(meas.tempIVoltage));
-	assertTrue(meas.tempO == toTempO(meas.tempOVoltage));
-	assertTrue(meas.lambda == toLambda(meas.lambdaVoltage));
+	// for voltages > 4950 and <= 5000 mV
+	assertTrue(meas.tempI > 990 && meas.tempI <= 1000);
+	assertTrue(meas.tempO == 400);
+	assertTrue(meas.lambda == 997);
 
 	return true;
 }
@@ -327,7 +324,7 @@
 
 // TODO assertions
 bool testUpdate(void) {
-	measurement meas = {0, 0, 0, 0, 0, 0};
+	measurement meas = {0, 0, 0};
 	updateMeas(meas);
 
 	return true;
@@ -335,7 +332,7 @@
 
 // TODO test display() with no display connected?
 bool testDisplay(void) {
-	measurement meas = {0, 0, 0, 0, 0, 0};
+	measurement meas = {0, 0, 0};
 	displayMeas(meas, "  ");
 
 	return true;
diff --git a/lambda/TODO b/lambda/TODO
index 350ea4b..e2dc7c5 100644
--- a/lambda/TODO
+++ b/lambda/TODO
@@ -1,5 +1,5 @@
 * C
-- What do static inline volatile extern in C do?
+- What do static inline extern in C do?
 - Read up on "global" variables and modules
 - Flexarray? http://en.wikipedia.org/wiki/Sizeof
 - License? (github)
@@ -13,5 +13,4 @@
 * Circuit
 - Look at oxygen sensor voltage with voltmeter/oscilloscope - is the voltage
   really so unstable?
-- Put button and beeper pins in pins.h (watch out with OCR1A)
-- Reset min/max measurements when enabling simulation mode
\ No newline at end of file
+- Put button and beeper pins in pins.h (watch out with OCR1A)
\ No newline at end of file
diff --git a/lambda/command.c b/lambda/command.c
index 4e39579..c3b9214 100644
--- a/lambda/command.c
+++ b/lambda/command.c
@@ -39,11 +39,13 @@
 	}
 	if (strcmp(fields[0], "se") == 0) {
 		// simulation enable
+		resetMeas();
 		simulation = true;
 		beep(1, 2);
 	}
 	else if (strcmp(fields[0], "sd") == 0) {
 		// simulation disable
+		resetMeas();
 		simulation = false;
 		beep(1, 2);
 	}
diff --git a/lambda/display.c b/lambda/display.c
index 468c540..cc3a3df 100644
--- a/lambda/display.c
+++ b/lambda/display.c
@@ -18,42 +18,49 @@
 #include "alert.h"
 
 #define MENU_OFF 0
-#define MENU_MIN_VALUES 1
-#define MENU_MAX_VALUES 2
+#define MENU_MAX_VALUES 1
 
 uint8_t position = MENU_OFF;
 bool updatePending = false;
 
 measurement measLatest;
-measurement measMin = {0, 20, 0, 20, 0, 1000};
-measurement measMax = {0, 0, 0, 0, 0, 2000};
+measurement measMax = {0, 0, 2000};
 
 void cycleDisplay(void) {
-	updatePending = true;
 	if (isAlertActive()) {
 		// button pressed during alert
 		cancelAlert();
+		updatePending = true;
 		return;
 	}
-	beep(1, 2);
 	position++;
 	if (position > MENU_MAX_VALUES) {
 		position = MENU_OFF;
 	}
+	updatePending = true;
+	beep(1, 2);
 }
 
 void updateMeas(measurement meas) {
 	measLatest = meas;
 
-	measMin.tempI = MIN(measMin.tempI, meas.tempI);
-	measMin.tempO = MIN(measMin.tempO, meas.tempO);
-	measMin.lambda = MAX(measMin.lambda, meas.lambda);
-
 	measMax.tempI = MAX(measMax.tempI, meas.tempI);
 	measMax.tempO = MAX(measMax.tempO, meas.tempO);
 	measMax.lambda = MIN(measMax.lambda, meas.lambda);
 
-	updateDisplay();
+	updatePending = true;
+}
+
+void resetMeas(void) {
+	measLatest.tempI = 0;
+	measLatest.tempO = 0;
+	measLatest.lambda = 2000;
+
+	measMax.tempI = 0;
+	measMax.tempO = 0;
+	measMax.lambda = 2000;
+
+	updatePending = true;
 }
 
 void updateDisplay(void) {
@@ -61,10 +68,8 @@
 		return;
 	}
 
-	if (position == MENU_MIN_VALUES) {
-		displayMeas(measMin, "|<");
-	} else if (position == MENU_MAX_VALUES) {
-		displayMeas(measMax, ">|");
+	if (position == MENU_MAX_VALUES) {
+		displayMeas(measMax, "|>");
 	} else {
 		displayMeas(measLatest, "  ");
 	}
@@ -81,9 +86,8 @@
 void printMeas(measurement meas) {
 	char log[64];
 	snprintf(log, sizeof(log),
-			"Ti %3d C %4u - To %3d C %4u - L %4u %4u\r\n",
-			meas.tempI, meas.tempIVoltage, meas.tempO, meas.tempOVoltage,
-			meas.lambda, meas.lambdaVoltage);
+			"Ti %3d C - To %3d C - L %4u \r\n",
+			meas.tempI, meas.tempO, meas.lambda);
 	printString(log);
 }
 
diff --git a/lambda/display.h b/lambda/display.h
index 231fb23..c769a19 100644
--- a/lambda/display.h
+++ b/lambda/display.h
@@ -15,12 +15,17 @@
 void cycleDisplay(void);
 
 /**
- * Updates the measurements, tracks min and max values since last start/reset
+ * Updates the measurements, tracks max values since last start/reset
  * and updates the display.
  */
 void updateMeas(measurement);
 
 /**
+ * Resets max measurements to initial values.
+ */
+void resetMeas(void);
+
+/**
  * Updates the display with the selected measurement values.
  */
 void updateDisplay(void);
diff --git a/lambda/interrupts.c b/lambda/interrupts.c
index 3d95b15..36db7b7 100644
--- a/lambda/interrupts.c
+++ b/lambda/interrupts.c
@@ -108,12 +108,12 @@
 
 void initTimers(void) {
 	// timer in normal mode is default
-	// timer clock prescaler/64 = 15.625 kHz overflowing every 16 ms
+	// timer0 clock prescaler/64 = 15.625 kHz overflowing every 16 ms
 	TCCR0B |= (1 << CS01) | (1 << CS00);
 
-	// Clear Timer on Compare Match mode, TOP OCR1A
+	// timer1 Clear Timer on Compare Match mode, TOP OCR1A
 	TCCR1B |= (1 << WGM12);
-	// timer clock prescaler/8
+	// timer1 clock prescaler/8
 	TCCR1B |= (1 << CS11);
 	// toggles PB1 at 7.8 kHz generating a 3.9 kHz beep
 	// OCR1A = 16;
diff --git a/lambda/sensors.c b/lambda/sensors.c
index 8ae747e..5bc571b 100644
--- a/lambda/sensors.c
+++ b/lambda/sensors.c
@@ -84,13 +84,9 @@
 			((lambdaVoltageAvg - 4) >> 3);
 
 	measurement meas;
-	meas.tempIVoltage = (tempIVoltageAvg >> 3);
-	meas.tempOVoltage = (tempOVoltageAvg >> 3);
-	meas.lambdaVoltage = (lambdaVoltageAvg >> 3);
-
-	meas.tempI = toTempI(meas.tempIVoltage);
-	meas.tempO = toTempO(meas.tempOVoltage);
-	meas.lambda = toLambda(meas.lambdaVoltage);
+	meas.tempI = toTempI(tempIVoltageAvg >> 3);
+	meas.tempO = toTempO(tempOVoltageAvg >> 3);
+	meas.lambda = toLambda(lambdaVoltageAvg >> 3);
 
 	return meas;
 }
diff --git a/lambda/sensors.h b/lambda/sensors.h
index 299fa44..7c93e8e 100644
--- a/lambda/sensors.h
+++ b/lambda/sensors.h
@@ -30,11 +30,8 @@
  * Measured values.
  */
 typedef struct {
-	uint16_t tempIVoltage;
 	int16_t tempI;
-	uint16_t tempOVoltage;
 	int16_t tempO;
-	uint16_t lambdaVoltage;
 	int16_t lambda;
 } measurement;