diff --git a/arduino_lite/main.c b/arduino_lite/main.c
index ef7a1ed..49d0deb 100644
--- a/arduino_lite/main.c
+++ b/arduino_lite/main.c
@@ -32,9 +32,7 @@
 
 void init(void) {
     
-    /* Make PORTD2..7 PORTD0..1 (Arduino digital 2..10) input by clearing bits in DDR */
-    //DDRD &= ~(_BV(PORTD2) | _BV(PORTD3) | _BV(PORTD4) | _BV(PORTD5) | _BV(PORTD6) | _BV(PORTD7));
-    //DDRB &= ~(_BV(PORTB0) | _BV(PORTB1));
+    /* Switch inputs. */
     pin_mode(2, INPUT);
     pin_mode(3, INPUT);
     pin_mode(4, INPUT);
@@ -48,33 +46,21 @@ void init(void) {
     /* you don’t connect anything to pin and if you try to read it, it will read as 1. Now, */
     /* when you externally drive that pin to zero(i.e. connect to ground / or pull-down),   */
     /* only then it will be read as 0. */
-
-    /* Enable pullups by setting bits in PORT. Default state is now high. */
-    PORTD |= (_BV(PORTD2) | _BV(PORTD3) | _BV(PORTD4) | _BV(PORTD5) | _BV(PORTD6) | _BV(PORTD7));
-    PORTB |= (_BV(PORTB0) | _BV(PORTB1));
     
-    /* Disable pullups by clearing bits in PORT. Default state is now low. */
-    /*
-    PORTD &= ~(_BV(PORTD2) | _BV(PORTD3) | _BV(PORTD4) | _BV(PORTD5) | _BV(PORTD6) | _BV(PORTD7));
-    PORTB &= ~(_BV(PORTB0) | _BV(PORTB1));
-    */
+    pin_pullup(2, DISABLE);
+    pin_pullup(3, DISABLE);
+    pin_pullup(4, DISABLE);
+    pin_pullup(5, DISABLE);
+    pin_pullup(6, DISABLE);
+    pin_pullup(7, DISABLE);
+    pin_pullup(8, DISABLE);
+    pin_pullup(9, DISABLE);
     
-    /* Make PORTB5 (Arduino digital 13) an output by setting bit in DDR. */
-    //DDRB |= _BV(PORTB5);
+    /* Blinken led. */
     pin_mode(13, OUTPUT);
     
 }
 
-/*
-int digital_read(int input_register, int pin) {
-    return bit_is_set(input_register, pin) != 0 ? 1 : 0;
-}
-
-void digital_write(int input_register, int pin) {
-    input_register |= _BV(pin);
-}
-*/
-
 int main(void) {    
     
     init();
@@ -83,18 +69,11 @@ int main(void) {
     stdin  = &uart_input;
     
     int  value;
-    //char buffer[9];  
         
     while (1) {
+        
         /* Blink led by toggling state of PORTB5 (Arduino digital 13). */
         PORTB ^= _BV(PORTB5);
-
-        /*
-        puts("PINB");
-        value = PINB;
-        itoa(value, buffer, 2);
-        puts(buffer);
-        */
         
         value = digital_read(2);
         printf("%d", value);
diff --git a/arduino_lite/pins.h b/arduino_lite/pins.h
index ab71ac3..e6a3829 100644
--- a/arduino_lite/pins.h
+++ b/arduino_lite/pins.h
@@ -25,7 +25,8 @@
 #define INPUT 0x0
 #define OUTPUT 0x1
 
-
+#define ENABLE 0x1
+#define DISABLE 0x0
 
 #define ARDUINOPIN_TO_TIMERID(x) TIMER_AT_PIN_##x
 #define ARDUINOPIN_TO_TCCRID(x) TCCR_AT_PIN_##x
@@ -548,9 +549,14 @@
 #define D_WRITE_0x1(pin)        D_WRITE_HIGH(pin) 
 #define D_WRITE_0x0(pin)        D_WRITE_LOW(pin)
 
+#define D_WRITE_ENABLE(pin)     D_WRITE_HIGH(pin) 
+#define D_WRITE_DISABLE(pin)    D_WRITE_LOW(pin)
+
 #define SET_OUTPUT(pin)         EXPAND_WRAPPER(_SET_OUTPUT, ARDUINOPIN_TO_PORTID(pin), ARDUINOPIN_TO_PORTMSK(pin) )
 #define SET_INPUT(pin)          EXPAND_WRAPPER(_SET_INTPUT, ARDUINOPIN_TO_PORTID(pin), ARDUINOPIN_TO_PORTMSK(pin) )
 
 #define pin_mode(pin, mode)     SET_##mode(pin)
+#define pin_pullup(pin, val)    D_WRITE_##val(pin)
+
 
 #endif /* PINS_H */