diff --git a/firmware/apps/tonictest.c b/firmware/apps/tonictest.c
index 29c8abf..bde21f1 100644
--- a/firmware/apps/tonictest.c
+++ b/firmware/apps/tonictest.c
@@ -1,21 +1,30 @@
 #include <pentabug/app.h>
 #include <pentabug/pentatonic.h>
+#include <pentabug/hal.h>
 
 static void init(void) {
-	pentatonic_direction(ALL_OUT);
+	pentatonic_direction(ALL_IN);
 }
 
 static void run(void) {
-	pentatonic_led_on(0);
+	pentatonic_direction(ALL_IN);
 
-	for(uint8_t i = 0; i < 5; ++i) {
-		wait_ms(500);
+	for(;;) {
+		uint8_t buttons = pentatonic_buttons();
 
-		pentatonic_led_on((i + 1) % 5);
+		if(buttons) {
+			pentatonic_direction(ALL_OUT);
 
-		wait_ms(200);
+			pentatonic_all_led_set(buttons);
 
-		pentatonic_led_off(i);
+			led_inv(RIGHT);
+
+			wait_ms(1000);
+
+			break;
+		}
+
+		wait_ms(1);
 	}
 }
 
diff --git a/firmware/include/pentabug/pentatonic.h b/firmware/include/pentabug/pentatonic.h
index 0991b3d..ea162c6 100644
--- a/firmware/include/pentabug/pentatonic.h
+++ b/firmware/include/pentabug/pentatonic.h
@@ -6,15 +6,31 @@
 #define ALL_OUT		0xff
 #define ALL_IN		0x00
 
+// every call affecting multiple LEDs/buttons expects a bitmap
+// the first 5 bits of this bitmap repressent the LEDs/buttons (from left to right)
+
+// set direction in which to use pentatonic extension, you might use one of the ALL_* from above
+// IMPORTANT: you have to call this function before using any other function from this file
 void pentatonic_direction(uint8_t direction);
 
+// direct access to single LED
 void pentatonic_led_on(uint8_t led);
 void pentatonic_led_off(uint8_t led);
 
+// turn multiple LEDs on or off with one call
 void pentatonic_multi_led_on(uint8_t leds);
 void pentatonic_multi_led_off(uint8_t leds);
 
+// set the state of a single LEDs
 void pentatonic_led_set(uint8_t led, uint8_t state);
+
+// sets the state of all LEDs
 void pentatonic_all_led_set(uint8_t leds);
 
+// get the state of all buttons
+uint8_t pentatonic_buttons(void);
+
+// get the state of a specific button
+uint8_t pentatonic_button(uint8_t button);
+
 #endif /* PENTATONIC_H */
diff --git a/firmware/lib/pentatonic.c b/firmware/lib/pentatonic.c
index b5ebea8..5e75122 100644
--- a/firmware/lib/pentatonic.c
+++ b/firmware/lib/pentatonic.c
@@ -3,8 +3,10 @@
 #include <avr/io.h>
 
 // pins affected by pentatonic on each port
-const uint8_t bits_c = (1 << 4) | (1 << 5);
-const uint8_t bits_d = (1 << 5) | (1 << 6) | (1 << 7);
+static const uint8_t bits_c = (1 << 4) | (1 << 5);
+static const uint8_t bits_d = (1 << 5) | (1 << 6) | (1 << 7);
+
+// these functions assign the pentatonic bits to pins on a port
 
 static inline uint8_t bits_to_c(uint8_t direction) {
 	return ((direction & (1 << 3)) << 2) | (direction & (1 << 4));
@@ -17,21 +19,18 @@ static inline uint8_t bits_to_d(uint8_t direction) {
 void pentatonic_direction(uint8_t direction) {
 	// map bits to pins
 
-	uint8_t part_c = bits_to_c(direction);
-	uint8_t part_d = bits_to_d(direction);
+	const uint8_t part_c = bits_to_c(direction);
+	const uint8_t part_d = bits_to_d(direction);
 
-	// reset everything
+	// reset direction
 
-	PORTC &= ~bits_c;
 	DDRC &= ~bits_c;
-
-	PORTD &= ~bits_d;
 	DDRD &= ~bits_d;
 
 	// pullup if input, off if output (inverted)
 
-	PORTC |= part_c;
-	PORTD |= part_d;
+	PORTC |= bits_c;
+	PORTD |= bits_d;
 
 	// set new direction
 
@@ -42,8 +41,8 @@ void pentatonic_direction(uint8_t direction) {
 void pentatonic_multi_led_on(uint8_t leds) {
 	// map bits to pins
 
-	uint8_t part_c = bits_to_c(leds);
-	uint8_t part_d = bits_to_d(leds);
+	const uint8_t part_c = bits_to_c(leds);
+	const uint8_t part_d = bits_to_d(leds);
 
 	// set leds on (inverted)
 
@@ -83,3 +82,19 @@ void pentatonic_all_led_set(uint8_t leds) {
 	pentatonic_multi_led_off(0xff);
 	pentatonic_multi_led_on(leds);
 }
+
+uint8_t pentatonic_buttons(void) {
+	// assign pins to pentatonic bits
+
+	uint8_t part_c = ((PINC & (1 << 5)) >> 2) | (PINC & (1 << 4));
+	uint8_t part_d = PIND >> 5 & 0b111;
+
+	// return inverted as switches are connected to ground
+
+	return ~(part_c | part_d) & 0b11111;
+}
+
+uint8_t pentatonic_button(uint8_t button) {
+	return pentatonic_buttons() & (1 << button);
+}
+