diff --git a/ard/pins.c b/ard/pins.c
index c29069b..a066cfb 100644
--- a/ard/pins.c
+++ b/ard/pins.c
@@ -137,21 +137,22 @@ unsigned int analog_read(unsigned char pin){
 }
 
 // TODO: write PWM to digital pins which allow it
-void analog_write(unsigned char pin, unsigned int value){
-	if(pin > 11){
+void analog_write(unsigned char pin, unsigned char value){
+	if(pin != 3 && pin != 5 && pin != 6 && pin != 9 && pin != 10 && pin != 11){
 		return;
 	}
 
-	if(value > 255){
-		value = 255;
-	}
+	// TODO maybe set pin mode?
 
-	/*if(value == HIGH){
-		PORTC |= _BV(pin);
-	}
-	else{
-		PORTC &= ~_BV(pin);
-	}*/
+	// clear timer on compare match
+	TCCR0A |= _BV(COM0A1)|_BV(WGM01)|_BV(WGM00);
+
+	// set interrupt on overflow and value to compare to
+	TIMSK0 |= _BV(TOIE0);
+	OCR0A = value;
+
+	// set timer scaling to 1, which starts the timer
+	TCCR0B |= _BV(CS00)|_BV(CS02);
 }
 
 // maps A0-A7 to 0-7
@@ -167,3 +168,8 @@ unsigned char map_analog_pin(unsigned char pin){
 ISR(ADC_vect){
 	// required but not used...
 }
+
+// fast PWM overflow interrupt handler
+ISR(TIMER0_OVF_vect){
+
+}
diff --git a/ard/pins.h b/ard/pins.h
index 150a93c..cb67122 100644
--- a/ard/pins.h
+++ b/ard/pins.h
@@ -19,6 +19,6 @@ void pin_mode(unsigned char, unsigned char);
 int digital_read(unsigned char);
 void digital_write(unsigned char, unsigned char);
 unsigned int analog_read(unsigned char);
-void analog_write(unsigned char, unsigned int);
+void analog_write(unsigned char, unsigned char);
 
 #endif
diff --git a/main.c b/main.c
index 37fb760..bfe5944 100644
--- a/main.c
+++ b/main.c
@@ -33,9 +33,11 @@ void prepare(){
 
 	// PWM example
 	pin_mode(A1, INPUT);
-	pin_mode(3, OUTPUT);
+	pin_mode(6, OUTPUT);
 }
 
+unsigned char pwm = 0;
+
 void loop(){
 	// digital input/output example
 	/*if(digital_read(10) && digital_read(8)){
@@ -54,7 +56,7 @@ void loop(){
 
 	// PWM example
 	int analog = map(analog_read(A1), 0, 1023, 0, 255);
-	analog_write(3, analog);
+	analog_write(6, analog);
 
 	char out[15];
 	sprintf(out, "%d", analog);