diff --git a/firmware/apps/blinker.c b/firmware/apps/blinker.c
index f7d604c..af6ac12 100644
--- a/firmware/apps/blinker.c
+++ b/firmware/apps/blinker.c
@@ -15,7 +15,7 @@ static void init(void) {
 static void blinker(void) {
 	led_inv(RIGHT);
 	led_inv(LEFT);
-	_delay_ms(500);
+	wait_ms(500);
 }
 
 REGISTER(blinker, init, NULL);
diff --git a/firmware/apps/music.c b/firmware/apps/music.c
index be04066..3610d7c 100644
--- a/firmware/apps/music.c
+++ b/firmware/apps/music.c
@@ -24,16 +24,16 @@ static void run(void) {
 	size_t i;
 	for(i = 0; i < sizeof(notes) / sizeof(*notes); ++i) {
 		if(notes[i] == NOTE_BREAK) {
-			_delay_ms(120);
+			wait_ms(180);
 		} else if(notes[i] == NOTE_SHORT) {
-			_delay_ms(20);
+			wait_ms(30);
 		} else {
 			set_note(notes[i], 4);
-			_delay_ms(180);
+			wait_ms(500);
 			test_stop_app();
 
 			stop_note();
-			_delay_ms(10);
+			wait_ms(10);
 			test_stop_app();
 		}
 	}
diff --git a/firmware/apps/test.c b/firmware/apps/test.c
deleted file mode 100644
index 2da1f78..0000000
--- a/firmware/apps/test.c
+++ /dev/null
@@ -1,15 +0,0 @@
-#include <stdlib.h>
-
-#include <avr/io.h>
-#define __DELAY_BACKWARD_COMPATIBLE__
-#include <util/delay.h>
-
-#include <pentabug/app.h>
-#include <pentabug/lifecycle.h>
-
-static void tester(void) {
-	PORTD ^= 1 << 4;
-	_delay_ms(100);
-}
-
-REG(tester);
diff --git a/firmware/include/pentabug/hal.h b/firmware/include/pentabug/hal.h
index a1ac34e..ce6f269 100644
--- a/firmware/include/pentabug/hal.h
+++ b/firmware/include/pentabug/hal.h
@@ -30,7 +30,11 @@ void led_inv(uint8_t led);
 
 // MOTOR
 
-void motor_on(uint8_t led);
-void motor_off(uint8_t led);
+void motor_on(void);
+void motor_off(void);
+
+// WAITING
+
+void wait_ms(uint16_t ms);
 
 #endif /* HAL_H */
diff --git a/firmware/lib/hal.c b/firmware/lib/hal.c
index 444873d..5068aee 100644
--- a/firmware/lib/hal.c
+++ b/firmware/lib/hal.c
@@ -9,8 +9,9 @@
 
 #include <pentabug/timer.h>
 
-static uint8_t ir_active = 0;
+static volatile uint8_t ir_active = 0;
 static int int_skip = 0;
+static volatile int16_t wait_time = 0;
 
 static int button_count[2];
 
@@ -25,7 +26,8 @@ inline static void major_interrupt(void) {
 			++button_count[i];
 		}
 
-		if(button_count[i] == 400) {
+		// 1s pressed
+		if(button_count[i] == 200) {
 			next_app(i ? 1 : -1);
 			PORTC ^= 1 << 2;
 		}
@@ -39,10 +41,12 @@ ISR(TIMER0_COMPA_vect) {
 
 	++int_skip;
 
-	if(int_skip >= 38 * 5) {
+	if(int_skip >= 64 * 5) {
 		int_skip = 0;
 		major_interrupt();
 	}
+
+	--wait_time;
 }
 
 void init_hw(void) {
@@ -109,3 +113,31 @@ void led_inv(uint8_t led) {
 	}
 }
 
+void motor_on(void) {
+	PORTB |= 1 << 6;
+}
+
+void motor_off(void) {
+	PORTB &= ~(1 << 6);
+}
+
+void wait_ms(uint16_t ms) {
+	// TODO: this function seems to be ~10% too fast
+	int32_t cycles = ms * (int32_t)64;
+
+	while(cycles >= INT16_MAX) {
+		cycles -= INT16_MAX;
+		wait_time = INT16_MAX;
+
+		while(wait_time > 0) {
+			test_stop_app();
+		}
+	}
+
+	wait_time = cycles;
+
+	while(wait_time > 0) {
+		test_stop_app();
+	}
+}
+