diff --git a/TeensyPwm.cpp b/TeensyPwm.cpp
index 670269c..a472c71 100644
--- a/TeensyPwm.cpp
+++ b/TeensyPwm.cpp
@@ -37,11 +37,11 @@ const float Ctrl_P = 5.0;
 const float Ctrl_I = 2.0;
 const float Ctrl_D = 0.0;
 
-const float U_des = 12.0;
+volatile float U_des = 12.0;
 
 
 LiquidCrystal lcd(LCD_RS, LCD_E, LCD_D4, LCD_D5, LCD_D6, LCD_D7);
-Control ctrl((float)PWM_MIN, (float)PWM_MAX, Ctrl_P, Ctrl_I, Ctrl_D);
+volatile Control ctrl((float)PWM_MIN, (float)PWM_MAX, Ctrl_P, Ctrl_I, Ctrl_D);
 
 
 
@@ -49,43 +49,47 @@ void setup() {
 	lcd.begin(LCD_COLS, LCD_ROWS);
 	lcd.print("Teensy SMPS");
 	pinMode(PWM_PIN, OUTPUT);
+	analogWrite(PWM_PIN, 0);
 	analogWriteFrequency(PWM_PIN, PWM_FREQ);
 	analogWriteResolution(PWM_RES);
+  attachInterrupt(PWM_PIN, cycle, RISING);
 
 	analogReadResolution(ADC_RES);
 	analogReference(DEFAULT);
 	// analogReadAveraging(16);
 	pinMode(ADC_IN, INPUT);
 
-	analogWrite(PWM_PIN, 0);
+}
+
+
+volatile uint32_t lastCycle = 0;
+volatile float u_curr = 0;
+volatile uint16_t newPwm = 0;
+volatile uint32_t cycleDelay = 0;
+volatile uint32_t maxCycleDelay = 0;
+
+void cycle() {
+	uint32_t currentTime = micros();
+	cycleDelay = currentTime - lastCycle;
+	if (cycleDelay > maxCycleDelay) {
+		maxCycleDelay = cycleDelay;
+	}
+	lastCycle = currentTime;
+	uint16_t adcIn = analogRead(ADC_IN);
+	float u_adc = ((float)adcIn) * U_ref / ((float)ADC_MAX);
+	u_curr = u_adc * (R_top + R_bottom) / R_bottom;
+
+	float newPwm_f = ctrl.cycle(U_des, u_curr);
+	newPwm = (uint16_t) newPwm_f;
+
+	analogWrite(PWM_PIN, newPwm);
 }
 
 void loop() {
-	static uint32_t lastCycle = 0;
-	static float u_curr = 0;
-	static uint16_t newPwm = 0;
-	static uint32_t cycleDelay = 0;
-	static uint32_t maxCycleDelay = 0;
-	static uint32_t cycleCnt = 0;
 
-	uint32_t currentTime = micros();
-	if ((lastCycle + CYCLE_TIME <= currentTime) || (lastCycle > currentTime)) {
-		cycleDelay = currentTime - lastCycle;
-		if (cycleDelay > maxCycleDelay) {
-			maxCycleDelay = cycleDelay;
-		}
-		lastCycle = currentTime;
-		uint16_t adcIn = analogRead(ADC_IN);
-		float u_adc = ((float)adcIn) * U_ref / ((float)ADC_MAX);
-		u_curr = u_adc * (R_top + R_bottom) / R_bottom;
-
-		float newPwm_f = ctrl.cycle(U_des, u_curr);
-		newPwm = (uint16_t) newPwm_f;
-
-		analogWrite(PWM_PIN, newPwm);
-	}
 
 	static uint32_t lastDisplayCycle = 0;
+	static uint32_t cycleCnt = 0;
 	currentTime = micros();
 	if ((lastDisplayCycle + DISPLAY_UPDATE_TIME <= currentTime) || (lastDisplayCycle > currentTime)) {
 		lastDisplayCycle = currentTime;
@@ -102,8 +106,9 @@ void loop() {
 		lcd.print(maxCycleDelay);
 		float dutyCycle = ((float)newPwm) / ((float)PWM_MAX) * 100.0;
 		lcd.setCursor(8, 1);
-		lcd.print(dutyCycle);
-		lcd.print("%");
+//		lcd.print(dutyCycle);
+//		lcd.print("%");
+    lcd.print(cycleDelay);
 
 	}
 }