diff --git a/lambda/Makefile b/lambda/Makefile
index 5525397..8da700c 100644
--- a/lambda/Makefile
+++ b/lambda/Makefile
@@ -3,7 +3,7 @@
 
 MCU = atmega328p
 # Currently supported are 1 MHz and 8 MHz
-F_CPU = 8000000
+F_CPU = 1000000
 # Also try BAUD = 19200 or 38400 if you're feeling lucky.
 BAUD = 9600
 
diff --git a/lambda/airgate.c b/lambda/airgate.c
index fbd7243..550086c 100644
--- a/lambda/airgate.c
+++ b/lambda/airgate.c
@@ -6,21 +6,23 @@
  */
 
 #include <stdlib.h>
+#include <stdbool.h>
 #include <avr/io.h>
 #include <avr/interrupt.h>
 #include <util/atomic.h>
 #include <util/delay.h>
 #include "airgate.h"
 #include "integers.h"
+#include "interrupts.h"
 
 // TODO pins
 
 /* Direction */
 volatile static int8_t dir = 0;
+/* Target position */
+volatile static uint8_t target = 0;
 /* Current position */
 volatile static uint16_t pos = 0;
-/* Target position */
-volatile static int16_t target = 0;
 /* Steps remaining */
 volatile static uint16_t steps = 0;
 /* Steps done */
@@ -52,7 +54,7 @@
 	// set start speed
 	OCR2A = speed;
 	// start timer2
-	TCCR2B |= (1 << CS22) | (1 << CS21);
+	TCCR2B |= TIMER2_PRESCALE;
 }
 
 /**
@@ -70,14 +72,13 @@
  * the motor.
  */
 static void set(void) {
-	int16_t diff = (target << SCALE) - pos;
+	stop();
+	int16_t diff = (((int16_t)target) << SCALE) - pos;
 	if (diff != 0) {
 		dir = MAX(-1, MIN(diff, 1));
 		speed = MIN_SPEED;
-		ATOMIC_BLOCK(ATOMIC_FORCEON) {
-			steps = abs(diff);
-			ramp = MIN(MIN_SPEED - MAX_SPEED, steps >> 1);
-		}
+		steps = abs(diff);
+		ramp = MIN(MIN_SPEED - MAX_SPEED, steps >> 1);
 		start();
 	}
 }
@@ -95,33 +96,35 @@
 		OCR2A = speed;
 	} else {
 		done = 0;
-		stop();
 		// move to new target position if necessary
 		set();
-		if (pos == 0) {
-			// driver sleep mode
-			// TODO when is it best to do this?
-			PORTC &= ~(1 << PC5);
-		}
 	}
 }
 
 void setAirgate(uint8_t const position) {
+	if (position == target) {
+		return;
+	}
+	target = position;
+	bool idle = false;
 	ATOMIC_BLOCK(ATOMIC_FORCEON) {
-		if (position == target) {
-			return;
-		}
-		target = position;
 		if (steps > 0) {
 			// motor busy - decelerate and move to target position when stopped
 			steps = MIN(ramp, steps);
 		} else {
 			// move to target position
-			set();
+			idle = true;
 		}
 	}
+	if (idle) {
+		set();
+	}
 }
 
 uint8_t getAirgate(void) {
 	return target;
 }
+
+void setSleepMode(void) {
+	PORTC &= ~(1 << PC5);
+}
diff --git a/lambda/airgate.h b/lambda/airgate.h
index 6fbf49f..cab1454 100644
--- a/lambda/airgate.h
+++ b/lambda/airgate.h
@@ -36,4 +36,9 @@
  */
 uint8_t getAirgate(void);
 
+/**
+ * Sets the driver in sleep mode.
+ */
+void setSleepMode(void);
+
 #endif /* AIRGATE_H_ */
diff --git a/lambda/interrupts.h b/lambda/interrupts.h
index 436faa1..385cff0 100644
--- a/lambda/interrupts.h
+++ b/lambda/interrupts.h
@@ -22,6 +22,8 @@
 	// #define TIMER1_CTC_TOP 15
 	// 2 kHz is less noisy on the small piezo beeper
 	#define TIMER1_COMP_MATCH 31
+	// timer2 clock prescaler/32 = 32.25 kHz @ 1MHz
+	#define TIMER2_PRESCALE (1 << CS21) | (1 << CS20)
 #elif F_CPU == 8000000
 	// timer0 clock prescaler/1024 = 7.812 kHz @ 8 MHz
 	#define TIMER0_PRESCALE (1 << CS02) | (1 << CS00)
@@ -33,6 +35,8 @@
 	// #define TIMER1_CTC_TOP 15
 	// 2 kHz is less noisy on the small piezo beeper
 	#define TIMER1_COMP_MATCH 31
+	// timer2 clock prescaler/256 = 32.25 kHz @ 8MHz
+	#define TIMER2_PRESCALE (1 << CS22) | (1 << CS21)
 #endif
 
 /**