diff --git a/lambda/rules.c b/lambda/rules.c
index a36b214..97e4d78 100644
--- a/lambda/rules.c
+++ b/lambda/rules.c
@@ -19,7 +19,6 @@
 
 uint8_t measCount = MEAS_INT;
 FireState state = undefined;
-// uint8_t airgate = 100;
 
 static int32_t deltaAvg = 0;
 static int16_t tempIMax = TEMP_INIT;
@@ -29,7 +28,7 @@
  * Pushes the given new value in the queue of temperature differences
  * and returns the oldest value being pushed off the array.
  */
-static int16_t pushQueue(const int16_t value) {
+static int16_t pushQueue(int16_t const value) {
 	int16_t last = tempIDiffQueue[QUEUE_SIZE - 1];
 	for (size_t i = QUEUE_SIZE - 1; i > 0; i--) {
 		tempIDiffQueue[i] = tempIDiffQueue[i - 1];
@@ -43,13 +42,26 @@
  * Initializes all elements in the queue of temperature differences
  * to the given value.
  */
-static void initQueue(const int16_t value) {
+static void initQueue(int16_t const value) {
 	for (size_t i = 0; i < QUEUE_SIZE; i++) {
 		tempIDiffQueue[i] = value;
 	}
 }
 
 /**
+ * Closes the airgate and puts the motor driver in sleep mode after a delay,
+ * giving the motor sufficient time.
+ */
+static void closeAirgateAndSleep(void) {
+	setAirgate(AIRGATE_CLOSE);
+	void func(void) {
+		setSleepMode(true);
+	}
+	// put stepper motor driver in sleep mode in 60 seconds
+	scheduleTask(func, 60);
+}
+
+/**
  * Reminds to set the air gate to 50% when the fire is still firing up
  * and the temperature has reached TEMP_AIRGATE_50.
  */
@@ -86,12 +98,7 @@
 	if (state == burning_down && meas.tempI < TEMP_AIRGATE_0 &&
 			meas.lambda >= LAMBDA_MAX && getAirgate() > AIRGATE_CLOSE) {
 		setHeaterState(heaterStateOff);
-		setAirgate(AIRGATE_CLOSE);
-		void func(void) {
-			setSleepMode(true);
-		}
-		// put stepper motor driver in sleep mode in 60 seconds
-		scheduleTask(func, 60);
+		closeAirgateAndSleep();
 		alert_P(BEEPS, LENGTH, TONE,
 				PSTR(MSG_AIRGATE_CLOSE_0), PSTR(""), false);
 		*fired = true;
@@ -151,7 +158,6 @@
 static void warmStart(bool* const fired, Measurement const meas) {
 	if (! *fired && state == firing_up &&
 			meas.tempI > TEMP_FIRE_OUT && tempIMax >= TEMP_AIRGATE_50) {
-		// TODO wake up driver here?
 		setSleepMode(false);
 		resetRules(false);
 		tempIMax = meas.tempI;
@@ -211,12 +217,12 @@
 	if (heaterUptime >= 1800 && meas.tempI < TEMP_FIRE_OUT &&
 			meas.lambda >= LAMBDA_MAX) {
 		setHeaterState(heaterStateOff);
-		setSleepMode(true);
+		closeAirgateAndSleep();
 	}
 	if (heaterUptime >= 10800 && meas.tempI < TEMP_AIRGATE_0 &&
 			meas.lambda >= LAMBDA_MAX) {
 		setHeaterState(heaterStateOff);
-		setSleepMode(true);
+		closeAirgateAndSleep();
 	}
 }
 
@@ -247,7 +253,7 @@
 }
 
 // called about every second
-void reason(Measurement meas) {
+void reason(Measurement const meas) {
 
 	tempIMax = MAX(tempIMax, meas.tempI);
 
diff --git a/lambda/scheduler.c b/lambda/scheduler.c
index 7f3b1bb..a0a8024 100644
--- a/lambda/scheduler.c
+++ b/lambda/scheduler.c
@@ -1,6 +1,11 @@
 /*
  * scheduler.c
  *
+ * Very basic task scheduler allowing to schedule up to three functions at a
+ * time to be executed when a given delay in seconds has passed. When a function
+ * was executed the task is set to done, freeing up a slot for another task to
+ * be scheduled.
+ *
  *  Created on: 09.03.2016
  *      Author: dode@luniks.net
  */
diff --git a/lambda/scheduler.h b/lambda/scheduler.h
index b5511d2..30c772c 100644
--- a/lambda/scheduler.h
+++ b/lambda/scheduler.h
@@ -37,6 +37,14 @@
  * Schedules the given function for execution after the given delay in seconds.
  * Returns false if the function could not be scheduled because there were
  * no free slots available, true otherwise.
+ * The function must have no return value and take no arguments. Arbitrary code
+ * can be passed for execution by wrapping it in such a function:
+ *
+ * void task(void) {
+ *     // some code here
+ * }
+ * // run task in 30 seconds
+ * scheduleTask(task, 30);
  */
 bool scheduleTask(void (*func)(void), uint16_t const delay);